How to Use This Soil Survey
Detailed Soil Maps
The detailed soil maps can be useful in planning the use and management of small areas.
To find information about your area of interest, you can locate the Section, Township, and Range by zooming in on the Index to Map Sheets, or you can go to the Web Soil Survey at (http://websoilsurvey.nrcs.usda.gov/app/).
Note the map unit symbols that are in that area. The Contents lists the map units by symbol and name and shows the page where each map unit is described.
See the Contents for sections of this publication that may address your specific needs. ii
This soil survey is a publication of the National Cooperative Soil Survey, a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local agencies. The Natural Resources Conservation Service (formerly the Soil Conservation Service) has leadership for the Federal part of the National Cooperative Soil Survey. Major fieldwork for this soil survey was completed in 1989. Soil names and descriptions were approved in 1991. Unless otherwise indicated, statements in this publication refer to conditions in the survey area in 1991. This survey was made cooperatively by the Natural Resources Conservation Service and the Montana Agricultural Experiment Station. It is part of the technical assistance furnished to the Deer Lodge Valley and North Powell Conservation Districts. Financial assistance was provided by the Old West Regional Commission in cooperation with the Montana Department of State Lands and the Montana Association of Conservation Districts, the Board of County Commissioners, and Powell County. The most current official data are available through the NRCS Soil Data Mart website at http://soildatamart.nrcs.usda.gov. Soil maps in this survey may be copied without permission. Enlargement of these maps, however, could cause misunderstanding of the detail of mapping. If enlarged, maps do not show the small areas of contrasting soils that could have been shown at a larger scale. The United States Department of Agriculture (USDA) prohibits discrimination in all of its programs on the basis of race, color, national origin, gender, religion, age, disability, political beliefs, sexual orientation, and marital or family status. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact the USDA’s TARGET Center at 202-720-2600 (voice or TDD). To file a complaint of discrimination, write USDA, Director, Office of Civil Rights, Room 326W, Whitten Building, 14th and Independence Avenue SW, Washington, DC 20250-9410, or call 202-720-5964 (voice or TDD). USDA is an equal opportunity provider and employer.
Cover: Deer Lodge Mountain and Mount Powell in southern Powell County Area. The lower elevation forested soils are mainly Worock gravelly loam, and the rangeland soils are mainly Roy- Shawmut-Danvers complex.
Additional information about the Nation’s natural resources is available online from the Natural Resources Conservation Service at http://www.nrcs.usda.gov. iii
Contents
Part I 379E—Ambrant-Rochester-Rock outcrop complex, 15 to 35 percent slopes...... 30 How To Use This Soil Survey ...... i 379F—Ambrant-Rochester-Rock outcrop Index to Taxonomic Units ...... xiv complex, 35 to 60 percent slopes...... 31 Index to Map Units ...... xv Anaconda Series ...... 32 Summary of Tables ...... xxiv 35B—Anaconda loam, 0 to 4 percent slopes .... 33 Foreword ...... xxvii Aquents...... 33 Introduction ...... 1 4—Aquents-Slickens complex, 0 to 2 percent General Nature of the Survey Area ...... 1 slopes, occasionally flooded ...... 33 History...... 1 Baggs Series ...... 34 Industry, Transportation, and Recreation ...... 2 135B—Baggs sandy loam, 0 to 4 percent Physiography and Drainage...... 2 slopes ...... 35 Geologic History and Regional Geology ...... 3 135C—Baggs sandy loam, 4 to 8 percent Geologic Units ...... 4 slopes ...... 35 Mineral Resources ...... 5 135D—Baggs sandy loam, 8 to 15 percent Ground-Water Resources ...... 6 slopes ...... 35 Seismic Activity ...... 6 479B—Baggs sandy loam, cool, 0 to 4 Climate...... 6 percent slopes ...... 36 How This Survey Was Made ...... 7 Beaverell Series ...... 36 Formation and Classification of the Soils ...... 13 132B—Beaverell cobbly loam, 0 to 4 percent Formation of the Soils ...... 13 slopes ...... 37 Classification of the Soils ...... 14 132C—Beaverell cobbly loam, 4 to 8 percent Soil Series and Detailed Soil Map Units ...... 25 slopes ...... 38 Ambrant Series ...... 26 332B—Beaverell loam, 0 to 4 percent slopes.... 38 79D—Ambrant-Rochester complex, cool, Bignell Series ...... 38 4 to 15 percent slopes ...... 27 99D—Bignell gravelly clay loam, 8 to 15 79E—Ambrant-Rochester complex, cool, percent slopes ...... 39 15 to 35 percent slopes ...... 27 99E—Bignell gravelly clay loam, 15 to 35 79F—Ambrant-Rochester complex, cool, percent slopes ...... 40 35 to 60 percent slopes ...... 28 99F—Bignell gravelly clay loam, 35 to 60 179E—Ambrant-Rochester complex, 15 to 35 percent slopes ...... 40 percent slopes ...... 28 199E—Bignell gravelly clay loam, cool, 179F—Ambrant-Rochester complex, 35 to 60 15 to 35 percent slopes ...... 40 percent slopes ...... 29 199F—Bignell gravelly clay loam, cool, 279E—Ambrant, cool-Rochester, cool-Rock 35 to 60 percent slopes ...... 41 outcrop complex, 15 to 35 percent 299E—Bignell-Yreka complex, 15 to 35 slopes ...... 29 percent slopes ...... 41 279F—Ambrant, cool-Rochester, cool-Rock 299F—Bignell-Yreka complex, 35 to 60 outcrop complex, 35 to 60 percent slopes... 30 percent slopes ...... 41 iv
399E—Bignell-Yreka complex, cool, 15 to 35 242C—Braziel-Perma gravelly loams, 4 to 8 percent slopes ...... 42 percent slopes ...... 56 399F—Bignell-Yreka complex, cool, 35 to 60 242D—Braziel gravelly loam, 8 to 15 percent percent slopes ...... 42 slopes ...... 56 499D—Bignell, cool-Yreka complex, 8 to 15 242E—Braziel gravelly loam, 15 to 35 percent percent slopes ...... 43 slopes ...... 56 499E—Bignell, cool-Yreka complex, 15 to 35 342D—Braziel stony loam, 8 to 15 percent percent slopes ...... 43 slopes ...... 57 499F—Bignell, cool-Yreka complex, 35 to 60 342E—Braziel stony loam, 15 to 35 percent percent slopes ...... 44 slopes ...... 57 699D—Bignell gravelly loam, 8 to 15 percent 342F—Braziel stony loam, 35 to 60 percent slopes ...... 44 slopes ...... 58 699E—Bignell gravelly loam, 15 to 35 percent 442D—Braziel-Tolbert complex, 8 to 15 slopes ...... 45 percent slopes ...... 58 699F—Bignell gravelly loam, 35 to 60 percent 442E—Braziel-Tolbert complex, 15 to 35 slopes ...... 45 percent slopes ...... 58 799D—Bignell-Yreka-Crow complex, 8 to 15 442F—Braziel-Tolbert complex, 35 to 60 percent slopes ...... 46 percent slopes ...... 59 799E—Bignell-Yreka-Crow complex, 15 to 35 742E—Braziel-Perma-Water complex, 8 to 25 percent slopes ...... 46 percent slopes ...... 59 999D—Bignell-Rumblecreek complex, 8 to 15 742F—Braziel-Perma-Water complex, 25 to 50 percent slopes ...... 47 percent slopes ...... 60 999E—Bignell-Rumblecreek complex, Bushong Series ...... 61 15 to 35 percent slopes ...... 47 10—Bushong loam, taxadjunct, 0 to 4 percent 999F—Bignell-Rumblecreek complex, slopes ...... 62 35 to 60 percent slopes ...... 48 632—Bushong loam, 0 to 4 percent slopes ...... 62 Blossberg Series ...... 48 832—Bushong loam, 0 to 4 percent slopes, 634—Blossberg loam, 0 to 4 percent slopes ..... 49 rarely flooded...... 62 834—Blossberg loam, 0 to 4 percent slopes, Canarway Series ...... 63 rarely flooded...... 50 Carten Series ...... 64 Bohnly Series ...... 50 110—Carten-Wetsand complex, 0 to 2 percent 109—Bohnly silt loam, 0 to 2 percent slopes .... 51 slopes, rarely flooded ...... 65 Boxwell Series ...... 51 432—Carten loam, 0 to 4 percent slopes, 69C—Boxwell loam, 4 to 8 percent slopes ...... 52 rarely flooded...... 65 69D—Boxwell loam, 8 to 15 percent slopes ...... 53 532—Carten loam, cool, 0 to 4 percent 69E—Boxwell loam, 15 to 35 percent slopes .... 53 slopes ...... 66 Braziel Series...... 53 562—Carten loam, 0 to 4 percent slopes ...... 66 200E—Braziel-Tolbert-Rock outcrop complex, Castner Series ...... 66 15 to 35 percent slopes ...... 55 Cetrack Series ...... 67 200F—Braziel-Tolbert-Rock outcrop complex, 34B—Cetrack loam, 0 to 4 percent slopes ...... 68 35 to 60 percent slopes ...... 55 34C—Cetrack loam, 4 to 8 percent slopes ...... 69 v
Clasoil Series ...... 69 Crow Series ...... 83 152B—Clasoil sandy loam, 0 to 4 percent 83D—Crow clay loam, 4 to 15 percent slopes ... 84 slopes ...... 70 83E—Crow clay loam, 15 to 35 percent 152C—Clasoil sandy loam, 4 to 8 percent slopes ...... 85 slopes ...... 70 283D—Crow clay loam, moist, 4 to 15 percent 152D—Clasoil sandy loam, 8 to 15 percent slopes ...... 85 slopes ...... 71 283E—Crow clay loam, moist, 15 to 35 552C—Clasoil-Crackerville complex, 4 to 8 percent slopes ...... 85 percent slopes ...... 71 883E—Crow-Bignell complex, moist, 8 to 25 552D—Clasoil-Crackerville complex, 8 to 15 percent slopes ...... 86 percent slopes ...... 72 883F—Crow-Bignell complex, moist, 25 to 50 552E—Clasoil-Crackerville complex, 15 to 35 percent slopes ...... 86 percent slopes ...... 72 983D—Crow-Bignell complex, 8 to 15 percent 752E—Clasoil-Crackerville-Rock outcrop slopes ...... 87 complex, 15 to 35 percent slopes...... 73 983E—Crow-Bignell complex, 15 to 35 Coben Series ...... 73 percent slopes ...... 87 58B—Coben loam, 0 to 4 percent slopes ...... 74 Danaher Series ...... 88 58C—Coben loam, 4 to 8 percent slopes ...... 75 87D—Danaher loam, 4 to 15 percent slopes .... 89 58D—Coben loam, 8 to 15 percent slopes ...... 75 87E—Danaher loam, 15 to 35 percent slopes ... 89 Comad Series ...... 75 387E—Danaher-Loberg complex, 15 to 35 280E—Comad-Elkner-Rock outcrop complex, percent slopes ...... 89 15 to 35 percent slopes ...... 76 Danvers Series ...... 90 280F—Comad-Elkner-Rock outcrop complex, 49B—Danvers clay loam, 0 to 4 percent 35 to 60 percent slopes ...... 77 slopes ...... 91 580E—Comad-Elkner complex, 15 to 35 49C—Danvers clay loam, 4 to 8 percent percent slopes ...... 77 slopes ...... 92 580F—Comad-Elkner complex, 35 to 60 49D—Danvers clay loam, 8 to 15 percent percent slopes ...... 78 slopes ...... 92 680F—Comad-Rubble land complex, 35 to 60 149B—Danvers cobbly clay loam, 0 to 4 percent slopes ...... 78 percent slopes ...... 92 Con Series ...... 79 149C—Danvers cobbly clay loam, 4 to 8 24B—Con loam, 0 to 4 percent slopes ...... 80 percent slopes ...... 93 24C—Con loam, 4 to 8 percent slopes ...... 80 149D—Danvers cobbly clay loam, 8 to 15 24D—Con loam, 8 to 15 percent slopes ...... 81 percent slopes ...... 93 824E—Con-Sixbeacon cobbly loams, 15 to 35 446B—Danvers-Roy complex, 0 to 4 percent percent slopes ...... 81 slopes ...... 93 824F—Con-Sixbeacon cobbly loams, 35 to 60 446C—Danvers-Roy complex, 4 to 8 percent percent slopes ...... 81 slopes ...... 94 Copenhaver Series ...... 82 446D—Danvers-Roy complex, 8 to 15 percent Crackerville Series ...... 83 slopes ...... 94 vi
Dolus Series ...... 95 482F—Elve gravelly loam, dry, 35 to 60 168C—Dolus-Boxwell complex, 4 to 8 percent percent slopes ...... 107 slopes ...... 96 682E—Elve bouldery sandy loam, 8 to 25 168D—Dolus-Boxwell complex, 8 to 15 percent slopes ...... 108 percent slopes ...... 96 682F—Elve bouldery sandy loam, 25 to 50 168E—Dolus-Boxwell complex, 15 to 35 percent slopes ...... 108 percent slopes ...... 97 982F—Elve-Rock outcrop complex, 35 to 60 268F—Dolus-Castner channery loams, percent slopes ...... 108 15 to 45 percent slopes ...... 97 Endoaquolls ...... 109 Doney Series ...... 98 Evaro Series ...... 109 169F—Doney-Dolus channery loams, 97D—Evaro gravelly loam, dry, 4 to 15 15 to 45 percent slopes ...... 99 percent slopes ...... 110 Dougcliff Series ...... 99 97E—Evaro gravelly loam, dry, 15 to 35 2—Dougcliff mucky peat, 0 to 2 percent percent slopes ...... 110 slopes, ponded ...... 100 97F—Evaro gravelly loam, dry, 35 to 60 103—Dumps, mine ...... 100 percent slopes ...... 111 DUMPS—Dumps, sanitary landfill ...... 100 197D—Evaro gravelly loam, 4 to 15 percent Elkner Series ...... 100 slopes ...... 111 80E—Elkner-Ovando complex, 15 to 35 197E—Evaro gravelly loam, 15 to 35 percent percent slopes ...... 101 slopes ...... 112 80F—Elkner-Ovando complex, 35 to 60 197F—Evaro gravelly loam, 35 to 60 percent percent slopes ...... 102 slopes ...... 112 Elliston Series ...... 102 Fergus Series ...... 112 6B—Elliston loam, 0 to 4 percent slopes, 40C—Fergus-Water complex, 2 to 8 percent rarely flooded...... 103 slopes ...... 114 Elve Series ...... 104 Fluvaquentic Endoaquolls ...... 114 82D—Elve gravelly loam, 4 to 15 percent 104A—Fluvaquentic Endoaquolls-Slickens slopes ...... 105 complex, 0 to 2 percent slopes, severely 82E—Elve gravelly loam, 15 to 35 percent impacted ...... 115 slopes ...... 105 Fluvaquents ...... 115 82F—Elve gravelly loam, 35 to 60 percent 7—Fluvaquents-Endoaquolls complex, slopes ...... 105 0 to 2 percent slopes, occasionally 382D—Elve gravelly loam, warm, 8 to 15 flooded...... 116 percent slopes ...... 106 Gregson Series ...... 116 382E—Elve gravelly loam, warm, 15 to 35 434—Gregson loam, cool, 0 to 4 percent percent slopes ...... 106 slopes, rarely flooded ...... 117 382F—Elve gravelly loam, warm, 35 to 60 444—Gregson loam, 0 to 4 percent slopes, percent slopes ...... 106 rarely flooded...... 117 482E—Elve gravelly loam, dry, 15 to 35 534—Gregson loam, cool, 0 to 4 percent percent slopes ...... 107 slopes ...... 117 vii
544—Gregson loam, 0 to 4 percent slopes ..... 118 Marcott Series...... 131 Helmville Series ...... 118 549—Marcott silty clay loam, 0 to 4 percent 84D—Helmville cobbly loam, 8 to 15 percent slopes ...... 132 slopes ...... 119 Martinsdale Series ...... 133 84E—Helmville cobbly loam, 15 to 35 percent 52B—Martinsdale loam, 0 to 4 percent slopes ...... 119 slopes ...... 134 84F—Helmville cobbly loam, 35 to 60 percent 52C—Martinsdale loam, 4 to 8 percent slopes ...... 120 slopes ...... 134 184E—Helmville cobbly loam, moist, 15 to 35 52D—Martinsdale loam, 8 to 15 percent percent slopes ...... 120 slopes ...... 134 184F—Helmville cobbly loam, moist, 35 to 60 352B—Martinsdale cobbly loam, 0 to 4 percent slopes ...... 120 percent slopes ...... 135 Hoyt Series ...... 121 352E—Martinsdale cobbly loam, 15 to 35 452D—Hoyt loam, 8 to 15 percent slopes ...... 122 percent slopes ...... 135 452E—Hoyt loam, 15 to 35 percent slopes ..... 122 Mccabe Series ...... 135 Kleinschmidt Series ...... 123 10A—Mccabe-Canarway complex, impacted, 547—Kleinschmidt gravelly loam, cool, 0 to 4 0 to 2 percent slopes, occasionally percent slopes ...... 124 flooded...... 136 557—Kleinschmidt gravelly loam, 0 to 4 11A—Mccabe-Canarway complex, 0 to 2 percent slopes ...... 124 percent slopes, occasionally flooded ...... 137 Lap Series...... 124 M-W—Miscellaneous Water ...... 137 Libeg Series ...... 125 Mocmont Series ...... 137 54D—Libeg gravelly loam, 8 to 15 percent 90F—Mocmont very gravelly loam, moist, slopes ...... 126 35 to 60 percent slopes ...... 139 54E—Libeg gravelly loam, 15 to 35 percent 190E—Mocmont very gravelly loam, 15 to 35 slopes ...... 126 percent slopes ...... 139 854D—Libeg-Monad-Copenhaver complex, 190F—Mocmont very gravelly loam, 35 to 60 8 to 15 percent slopes ...... 127 percent slopes ...... 139 854E—Libeg-Monad-Copenhaver complex, Mollet Series ...... 140 15 to 35 percent slopes ...... 127 48D—Mollet loam, 4 to 15 percent slopes ...... 141 854F—Libeg-Monad-Copenhaver complex, 48E—Mollet loam, 15 to 35 percent slopes ..... 141 35 to 60 percent slopes ...... 128 Monad Series ...... 141 Loberg Series ...... 129 50C—Monad loam, 2 to 8 percent slopes ...... 142 85D—Loberg gravelly loam, 4 to 15 percent 50D—Monad loam, 8 to 15 percent slopes ..... 142 slopes ...... 130 50E—Monad loam, 15 to 35 percent slopes ... 143 85E—Loberg gravelly loam, 15 to 35 percent Ovando Series ...... 143 slopes ...... 130 180F—Ovando-Elkner complex, 35 to 60 385D—Loberg gravelly loam, moist, 4 to 15 percent slopes ...... 144 percent slopes ...... 130 780E—Ovando-Elkner-Rock outcrop complex, 385E—Loberg gravelly loam, moist, 15 to 35 15 to 35 percent slopes ...... 144 percent slopes ...... 131 viii
780F—Ovando-Elkner-Rock outcrop complex, Poronto Series ...... 153 35 to 60 percent slopes ...... 145 637—Poronto loam, 0 to 4 percent slopes ...... 154 Perma Series ...... 145 837—Poronto loam, 0 to 4 percent slopes, 41B—Perma gravelly loam, 0 to 4 percent rarely flooded...... 155 slopes ...... 146 Quigley Series ...... 155 41C—Perma gravelly loam, 4 to 8 percent 60B—Quigley loam, 0 to 4 percent slopes ...... 156 slopes ...... 147 60C—Quigley loam, 4 to 8 percent slopes ...... 157 41D—Perma gravelly loam, 8 to 15 percent 60D—Quigley loam, 8 to 15 percent slopes .... 157 slopes ...... 147 63C—Quigley-Straw-Water complex, 2 to 8 41E—Perma gravelly loam, 15 to 35 percent percent slopes ...... 158 slopes ...... 147 63E—Quigley-Straw-Water complex, 8 to 25 41F—Perma gravelly loam, 35 to 60 percent percent slopes ...... 158 slopes ...... 148 460C—Quigley cobbly loam, 4 to 8 percent 241B—Perma stony loam, 0 to 4 percent slopes ...... 159 slopes ...... 148 Redchief Series ...... 159 241C—Perma stony loam, 4 to 8 percent 45D—Redchief cobbly loam, 4 to 15 percent slopes ...... 149 slopes ...... 160 241D—Perma stony loam, 8 to 15 percent 45E—Redchief cobbly loam, 15 to 35 slopes ...... 149 percent slopes ...... 160 241E—Perma stony loam, 15 to 35 percent 845D—Redchief-Copenhaver gravelly loams, slopes ...... 149 8 to 15 percent slopes ...... 161 338C—Perma cobbly loam, 4 to 8 percent 845E—Redchief-Copenhaver gravelly loams, slopes ...... 150 15 to 35 percent slopes ...... 161 338D—Perma cobbly loam, 8 to 15 percent Relyea Series ...... 162 slopes ...... 150 185E—Relyea-Helmville complex, 15 to 35 338E—Perma cobbly loam, 15 to 35 percent percent slopes ...... 163 slopes ...... 150 185F—Relyea-Helmville complex, 35 to 60 338F—Perma cobbly loam, 35 to 60 percent percent slopes ...... 164 slopes ...... 151 485E—Relyea-Helmville complex, moist, 542E—Perma very bouldery loam, 8 to 25 15 to 35 percent slopes ...... 164 percent slopes ...... 151 485F—Relyea-Helmville complex, moist, 542F—Perma very bouldery loam, 25 to 50 35 to 60 percent slopes ...... 165 percent slopes ...... 152 Rittel Series ...... 165 642E—Perma extremely bouldery loam, 91E—Rittel loam, 15 to 35 percent slopes ...... 166 8 to 50 percent slopes ...... 152 Rochester Series ...... 166 838E—Perma-Whitlash-Rock outcrop Roy Series ...... 167 complex, 15 to 35 percent slopes...... 152 46B—Roy gravelly loam, 0 to 4 percent 838F—Perma-Whitlash-Rock outcrop slopes ...... 168 complex, 35 to 60 percent slopes...... 153 46C—Roy gravelly loam, 4 to 8 percent 102—Pits, gravel ...... 153 slopes ...... 169 ix
46D—Roy gravelly loam, 8 to 15 percent 51B—Shawmut gravelly loam, 0 to 4 percent slopes ...... 169 slopes ...... 180 146D—Roy cobbly loam, 8 to 15 percent 51C—Shawmut gravelly loam, 4 to 8 percent slopes ...... 169 slopes ...... 180 146E—Roy cobbly loam, 15 to 35 percent 51D—Shawmut gravelly loam, 8 to 15 percent slopes ...... 170 slopes ...... 181 351E—Roy-Shawmut-Danvers complex, 53B—Shawmut-Martinsdale complex, 0 to 4 15 to 35 percent slopes ...... 170 percent slopes ...... 181 351F—Roy-Shawmut-Danvers complex, 53C—Shawmut-Martinsdale complex, 4 to 8 35 to 60 percent slopes ...... 171 percent slopes ...... 181 846D—Roy-Tolbert complex, 8 to 15 percent 151C—Shawmut cobbly loam, 4 to 8 percent slopes ...... 171 slopes ...... 182 846E—Roy-Tolbert complex, 15 to 35 percent 151D—Shawmut cobbly loam, 8 to 15 percent slopes ...... 172 slopes ...... 182 846F—Roy-Tolbert complex, 35 to 60 percent 151E—Shawmut cobbly loam, 15 to 35 slopes ...... 172 percent slopes ...... 183 100—Rubble land-Rock outcrop complex ...... 173 151F—Shawmut cobbly loam, 35 to 60 Rumblecreek Series ...... 173 percent slopes ...... 183 271C—Rumblecreek-Water complex, 2 to 8 251D—Shawmut stony loam, 0 to 15 percent percent slopes ...... 174 slopes ...... 183 271E—Rumblecreek-Water complex, 8 to 25 251E—Shawmut stony loam, 15 to 35 percent slopes ...... 174 percent slopes ...... 184 271F—Rumblecreek-Water complex, 25 to 50 451E—Shawmut very bouldery loam, 8 to 25 percent slopes ...... 175 percent slopes ...... 184 395D—Rumblecreek gravelly loam, 8 to 15 451F—Shawmut very bouldery loam, percent slopes ...... 175 25 to 50 percent slopes ...... 184 395E—Rumblecreek gravelly loam, 15 to 35 551F—Shawmut extremely bouldery loam, percent slopes ...... 175 8 to 50 percent slopes ...... 185 395F—Rumblecreek gravelly loam, 35 to 60 651C—Shawmut-Winspect-Water complex, percent slopes ...... 176 2 to 8 percent slopes ...... 185 Saypo Series ...... 176 651E—Shawmut-Winspect-Water complex, 435—Saypo loam, cool, 0 to 4 percent slopes, 8 to 25 percent slopes ...... 186 rarely flooded...... 177 651F—Shawmut-Winspect-Water complex, 445—Saypo loam, 0 to 4 percent slopes, 25 to 50 percent slopes ...... 186 rarely flooded...... 177 Silverchief Series ...... 187 535—Saypo loam, cool, 0 to 4 percent 599D—Silverchief-Trapps complex, 8 to 15 slopes ...... 178 percent slopes ...... 188 545—Saypo loam, 0 to 4 percent slopes ...... 178 599E—Silverchief-Trapps complex, 15 to 35 Shawmut Series ...... 178 percent slopes ...... 188 x
Sixbeacon Series ...... 189 93E—Tigeron very gravelly loam, 15 to 35 137B—Sixbeacon cobbly loam, 0 to 4 percent percent slopes ...... 201 slopes ...... 190 93F—Tigeron very gravelly loam, 35 to 60 137C—Sixbeacon cobbly loam, 4 to 8 percent percent slopes ...... 202 slopes ...... 190 Tolbert Series ...... 202 137D—Sixbeacon cobbly loam, 8 to 15 Trapps Series ...... 203 percent slopes ...... 190 98E—Trapps gravelly loam, 15 to 35 percent 237B—Sixbeacon gravelly loam, 0 to 4 slopes ...... 204 percent slopes ...... 191 98F—Trapps gravelly loam, 35 to 60 percent 237C—Sixbeacon gravelly loam, 4 to 8 slopes ...... 204 percent slopes ...... 191 198E—Trapps-Yreka stony loams, 8 to 25 5—Slickens-Aquents complex, 0 to 2 percent percent slopes ...... 204 slopes, 298D—Trapps channery loam, 4 to 25 occasionally flooded ...... 191 percent slopes ...... 205 105A—Slickens-Fluvaquentic Endoaquolls 298F—Trapps channery loam, 25 to 60 complex, 0 to 2 percent slopes, severely percent slopes ...... 205 impacted ...... 192 298G—Trapps channery loam, 60 to 80 Straw Series ...... 192 percent slopes ...... 206 25B—Straw loam, 0 to 4 percent slopes ...... 193 Turrah Series ...... 206 Tanna Series ...... 193 649—Turrah silty clay loam, 0 to 4 percent 65C—Tanna loam, 4 to 8 percent slopes ...... 194 slopes ...... 207 65D—Tanna loam, 8 to 15 percent slopes ...... 195 Varney Series ...... 207 265C—Tanna-Boxwell loams, 4 to 8 percent 31B—Varney clay loam, 0 to 4 percent slopes ...... 195 slopes ...... 208 265D—Tanna-Boxwell loams, 8 to 15 percent 31C—Varney clay loam, 4 to 8 percent slopes ...... 195 slopes ...... 209 Tetonview Series ...... 196 31D—Varney clay loam, 8 to 15 percent 635—Tetonview loam, 0 to 4 percent slopes ... 197 slopes ...... 209 735—Tetonview-Blossberg loams, 0 to 4 36B—Varney-Con loams, 0 to 4 percent percent slopes, rarely flooded ...... 197 slopes ...... 210 835—Tetonview loam, 0 to 4 percent slopes, 36C—Varney-Con loams, 4 to 8 percent rarely flooded...... 198 slopes ...... 210 Tevis Series ...... 198 36D—Varney-Con loams, 8 to 15 percent 486D—Tevis gravelly loam, 4 to 15 percent slopes ...... 211 slopes ...... 199 131E—Varney cobbly clay loam, 15 to 35 486E—Tevis gravelly loam, 15 to 35 percent percent slopes ...... 211 slopes ...... 200 131F—Varney cobbly clay loam, 35 to 50 486F—Tevis gravelly loam, 35 to 60 percent percent slopes ...... 211 slopes ...... 200 136E—Varney-Con complex, 15 to 35 Tigeron Series ...... 200 percent slopes ...... 212 xi
236B—Varney sandy clay loam, 2 to 4 371C—Wildgen-Yreka gravelly loams, 2 to 8 percent slopes ...... 212 percent slopes ...... 223 236C—Varney sandy clay loam, 4 to 8 371E—Wildgen-Yreka gravelly loams, 8 to 25 percent slopes ...... 213 percent slopes ...... 224 236D—Varney sandy clay loam, 8 to 15 371F—Wildgen-Yreka gravelly loams, percent slopes ...... 213 25 to 50 percent slopes ...... 224 331B—Varney clay loam, 0 to 4 percent Windham Series ...... 225 slope, impacted ...... 213 42E—Windham gravelly loam, 15 to 35 336B—Varney-Anaconda loams, 0 to 4 percent slopes ...... 226 percent slopes, impacted ...... 214 42F—Windham gravelly loam, 35 to 60 336C—Varney-Anaconda loams, 4 to 8 percent slopes ...... 226 percent slopes, impacted ...... 214 839E—Windham-Lap gravelly loams, 15 to 35 W—Water ...... 215 percent slopes ...... 226 Wetsand Series ...... 215 839F—Windham-Lap gravelly loams, 35 to 60 Whitecow Series ...... 216 percent slopes ...... 227 88E—Whitecow gravelly loam, dry, 15 to 35 Winfall Series ...... 227 percent slopes ...... 217 71C—Winfall gravelly loam, 2 to 8 percent 88F—Whitecow gravelly loam, dry, 35 to 60 slopes ...... 228 percent slopes ...... 217 71E—Winfall gravelly loam, 8 to 25 percent 88G—Whitecow gravelly loam, dry, 60 to 80 slopes ...... 228 percent slopes ...... 217 71F—Winfall gravelly loam, 25 to 50 percent 488E—Whitecow gravelly loam, cool, slopes ...... 229 15 to 35 percent slopes ...... 218 171C—Winfall-Rumblecreek gravelly loams, 488F—Whitecow gravelly loam, cool, 2 to 8 percent slopes ...... 229 35 to 60 percent slopes ...... 218 171E—Winfall-Rumblecreek gravelly loams, 488G—Whitecow gravelly loam, cool, 8 to 25 percent slopes ...... 230 60 to 80 percent slopes ...... 218 171F—Winfall-Rumblecreek gravelly loams, 788F—Whitecow, cool-Rock outcrop complex, 25 to 50 percent slopes ...... 230 35 to 60 percent slopes ...... 219 Winkler Series...... 231 988F—Whitecow-Rock outcrop complex, 86D—Winkler gravelly loam, 8 to 15 percent 35 to 60 percent slopes ...... 219 slopes ...... 232 988G—Whitecow-Rock outcrop complex, 86E—Winkler gravelly loam, 15 to 35 percent 60 to 80 percent slopes ...... 220 slopes ...... 232 Whitlash Series ...... 220 86F—Winkler gravelly loam, 35 to 60 percent Whitore Series ...... 221 slopes ...... 232 92E—Whitore gravelly loam, 15 to 35 percent 86G—Winkler gravelly loam, 60 to 80 percent slopes ...... 222 slopes ...... 233 92F—Whitore gravelly loam, 35 to 60 percent 786D—Winkler gravelly loam, cool, 8 to 15 slopes ...... 222 percent slopes ...... 233 Wildgen Series ...... 222 xii
786E—Winkler gravelly loam, cool, 15 to 35 596E—Worock, cool-Loberg complex, percent slopes ...... 234 15 to 35 percent slopes ...... 243 786F—Winkler gravelly loam, cool, 35 to 60 596F—Worock, cool-Loberg complex, percent slopes ...... 234 35 to 60 percent slopes ...... 244 786G—Winkler gravelly loam, cool, 60 to 80 696E—Worock gravelly loam, dry, 15 to 35 percent slopes ...... 234 percent slopes ...... 244 886E—Winkler-Rubble land-Rock outcrop 696F—Worock gravelly loam, dry, 35 to 60 complex, 15 to 35 percent slopes...... 235 percent slopes ...... 245 886F—Winkler-Rubble land-Rock outcrop 996E—Worock-Rock outcrop complex, complex, 35 to 60 percent slopes...... 235 15 to 35 percent slopes ...... 245 886G—Winkler-Rubble land-Rock outcrop 996F—Worock-Rock outcrop complex, complex, 60 to 80 percent slopes...... 236 35 to 60 percent slopes ...... 246 Winspect Series ...... 236 Yreka Series ...... 246 39C—Winspect gravelly loam, 4 to 8 percent 95D—Yreka gravelly loam, 8 to 15 percent slopes ...... 237 slopes ...... 247 39D—Winspect gravelly loam, 8 to 15 percent 95E—Yreka gravelly loam, 15 to 35 percent slopes ...... 237 slopes ...... 247 39E—Winspect gravelly loam, 15 to 35 95F—Yreka gravelly loam, 35 to 60 percent percent slopes ...... 238 slopes ...... 248 39F—Winspect gravelly loam, 35 to 60 195E—Yreka gravelly loam, cool, 15 to 35 percent slopes ...... 238 percent slopes ...... 248 Worock Series...... 239 195F—Yreka gravelly loam, cool, 35 to 60 96D—Worock gravelly loam, cool, 8 to 15 percent slopes ...... 248 percent slopes ...... 240 995E—Yreka-Rock outcrop complex, 15 to 35 96E—Worock gravelly loam, cool, 15 to 35 percent slopes ...... 249 percent slopes ...... 240 995F—Yreka-Rock outcrop complex, 35 to 60 96F—Worock gravelly loam, cool, 35 to 60 percent slopes ...... 249 percent slopes ...... 240 References ...... 251 196E—Worock-Loberg complex, 15 to 35 Glossary ...... 253 percent slopes ...... 241 196F—Worock-Loberg complex, 35 to 60 percent slopes ...... 241 Part II 396D—Worock gravelly loam, 8 to 15 percent slopes ...... 242 How to Use This Survey ...... i 396E—Worock gravelly loam, 15 to 35 Detailed Soil Map Unit Legend ...... iv percent slopes ...... 242 Summary of Tables ...... xii 396F—Worock gravelly loam, 35 to 60 Introduction ...... 1 percent slopes ...... 242 Agronomy ...... 11 596D—Worock, cool-Loberg complex, 8 to 15 Cropland Limitations and Hazards ...... 11 percent slopes ...... 243 Crop Yield Estimates...... 12 xiii
Pasture and Hayland Management ...... 13 Elements of Wildlife Habitat ...... 259 Land Capability Classification...... 13 Kinds of Wildlife Habitat ...... 259 Prime Farmland and Other Important Wildlife of the Powell County Area ...... 260 Farmland ...... 14 Engineering ...... 263 Erosion Factors ...... 15 Building Site Development ...... 263 Range ...... 79 Sanitary Facilities ...... 264 Similarity Index ...... 80 Waste Management ...... 265 Rangeland Management ...... 80 Construction Materials ...... 266 Understory Management ...... 81 Water Management ...... 267 Forestland ...... 181 Soil Properties ...... 421 Woodland Ordination System ...... 181 Engineering Index Properties ...... 421 Forestland Management and Productivity ...... 182 Physical and Chemical Properties ...... 422 Main Forest Access Road Water Features ...... 424 Limitations and Hazards ...... 183 Soil Features ...... 425 Recreation...... 221 References ...... 675 Wildlife Habitat ...... 259 Glossary ...... 679
Issued 2003 xiv
Index to Taxonomic Units
Ambrant Series ...... 26 Loberg Series ...... 129 Anaconda Series ...... 32 Marcott Series ...... 131 Aquents ...... 33 Martinsdale Series ...... 133 Baggs Series ...... 34 Mccabe Series ...... 135 Beaverell Series ...... 36 Mocmont Series ...... 137 Bignell Series ...... 38 Mollet Series ...... 140 Blossberg Series ...... 48 Monad Series ...... 141 Bohnly Series ...... 50 Ovando Series ...... 143 Boxwell Series ...... 51 Perma Series ...... 145 Braziel Series ...... 53 Poronto Series ...... 153 Bushong Series ...... 61 Quigley Series ...... 155 Canarway Series ...... 63 Redchief Series ...... 159 Carten Series ...... 64 Relyea Series ...... 162 Castner Series ...... 66 Rittel Series ...... 165 Cetrack Series ...... 67 Rochester Series ...... 166 Clasoil Series ...... 69 Roy Series ...... 167 Coben Series ...... 73 Rumblecreek Series ...... 173 Comad Series ...... 75 Saypo Series ...... 176 Con Series ...... 79 Shawmut Series ...... 178 Copenhaver Series ...... 82 Silverchief Series ...... 187 Crackerville Series ...... 83 Sixbeacon Series ...... 189 Crow Series ...... 83 Straw Series ...... 192 Danaher Series ...... 88 Tanna Series...... 193 Danvers Series ...... 90 Tetonview Series ...... 196 Dolus Series ...... 95 Tevis Series ...... 198 Doney Series ...... 98 Tigeron Series ...... 200 Dougcliff Series ...... 99 Tolbert Series ...... 202 Elkner Series ...... 100 Trapps Series...... 203 Elliston Series ...... 102 Turrah Series ...... 206 Elve Series ...... 104 Varney Series ...... 207 Endoaquolls ...... 109 Wetsand Series ...... 215 Evaro Series ...... 109 Whitecow Series ...... 216 Fergus Series ...... 112 Whitlash Series ...... 220 Fluvaquentic Endoaquolls ...... 114 Whitore Series ...... 221 Fluvaquents ...... 115 Wildgen Series ...... 222 Gregson Series ...... 116 Windham Series ...... 225 Helmville Series...... 118 Winfall Series...... 227 Hoyt Series ...... 121 Winkler Series ...... 231 Kleinschmidt Series ...... 123 Winspect Series ...... 236 Lap Series ...... 124 Worock Series ...... 239 Libeg Series ...... 125 Yreka Series ...... 246 xv
Index to Map Units
2—Dougcliff mucky peat, 0 to 2 percent 39E—Winspect gravelly loam, 15 to 35 slopes, ponded ...... 100 percent slopes ...... 238 4—Aquents-Slickens complex, 0 to 2 percent 39F—Winspect gravelly loam, 35 to 60 slopes, occasionally flooded ...... 33 percent slopes ...... 238 5—Slickens-Aquents complex, 0 to 2 percent 40C—Fergus-Water complex, 2 to 8 percent slopes, occasionally flooded ...... 191 slopes ...... 114 6B—Elliston loam, 0 to 4 percent slopes, 41B—Perma gravelly loam, 0 to 4 percent rarely flooded ...... 103 slopes ...... 146 7—Fluvaquents-Endoaquolls complex, 41C—Perma gravelly loam, 4 to 8 percent 0 to 2 percent slopes, occasionally slopes ...... 147 flooded ...... 116 41D—Perma gravelly loam, 8 to 15 percent 10—Bushong loam, taxadjunct, 0 to 4 percent slopes ...... 147 slopes ...... 62 41E—Perma gravelly loam, 15 to 35 percent 10A—Mccabe-Canarway complex, impacted, slopes ...... 147 0 to 2 percent slopes, occasionally 41F—Perma gravelly loam, 35 to 60 percent flooded...... 136 slopes ...... 148 11A—Mccabe-Canarway complex, 0 to 2 42E—Windham gravelly loam, 15 to 35 percent slopes, occasionally flooded ...... 137 percent slopes ...... 226 24B—Con loam, 0 to 4 percent slopes ...... 80 42F—Windham gravelly loam, 35 to 60 24C—Con loam, 4 to 8 percent slopes ...... 80 percent slopes ...... 226 24D—Con loam, 8 to 15 percent slopes ...... 81 45D—Redchief cobbly loam, 4 to 15 percent 25B—Straw loam, 0 to 4 percent slopes ...... 193 slopes ...... 160 31B—Varney clay loam, 0 to 4 percent 45E—Redchief cobbly loam, 15 to 35 percent slopes ...... 208 slopes ...... 160 31C—Varney clay loam, 4 to 8 percent 46B—Roy gravelly loam, 0 to 4 percent slopes ...... 209 slopes ...... 168 31D—Varney clay loam, 8 to 15 percent 46C—Roy gravelly loam, 4 to 8 percent slopes ...... 209 slopes ...... 169 34B—Cetrack loam, 0 to 4 percent slopes...... 68 46D—Roy gravelly loam, 8 to 15 percent 34C—Cetrack loam, 4 to 8 percent slopes ...... 69 slopes ...... 169 35B—Anaconda loam, 0 to 4 percent 48D—Mollet loam, 4 to 15 percent slopes ...... 141 slopes ...... 33 48E—Mollet loam, 15 to 35 percent slopes .... 141 36B—Varney-Con loams, 0 to 4 percent 49B—Danvers clay loam, 0 to 4 percent slopes ...... 210 slopes ...... 91 36C—Varney-Con loams, 4 to 8 percent 49C—Danvers clay loam, 4 to 8 percent slopes ...... 210 slopes ...... 92 36D—Varney-Con loams, 8 to 15 percent 49D—Danvers clay loam, 8 to 15 percent slopes ...... 211 slopes ...... 92 39C—Winspect gravelly loam, 4 to 8 percent 50C—Monad loam, 2 to 8 percent slopes ...... 142 slopes ...... 237 50D—Monad loam, 8 to 15 percent slopes..... 142 39D—Winspect gravelly loam, 8 to 15 percent 50E—Monad loam, 15 to 35 percent slopes ...... 237 slopes ...... 143 xvi
51B—Shawmut gravelly loam, 0 to 4 percent 71F—Winfall gravelly loam, 25 to 50 percent slopes ...... 180 slopes ...... 229 51C—Shawmut gravelly loam, 4 to 8 percent 79D—Ambrant-Rochester complex, cool, slopes ...... 180 4 to 15 percent slopes...... 27 51D—Shawmut gravelly loam, 8 to 15 percent 79E—Ambrant-Rochester complex, cool, slopes ...... 181 15 to 35 percent slopes ...... 27 52B—Martinsdale loam, 0 to 4 percent 79F—Ambrant-Rochester complex, cool, slopes ...... 134 35 to 60 percent slopes ...... 28 52C—Martinsdale loam, 4 to 8 percent 80E—Elkner-Ovando complex, 15 to 35 slopes ...... 134 percent slopes ...... 101 52D—Martinsdale loam, 8 to 15 percent 80F—Elkner-Ovando complex, 35 to 60 slopes ...... 134 percent slopes ...... 102 53B—Shawmut-Martinsdale complex, 0 to 4 82D—Elve gravelly loam, 4 to 15 percent percent slopes ...... 181 slopes ...... 105 53C—Shawmut-Martinsdale complex, 4 to 8 82E—Elve gravelly loam, 15 to 35 percent percent slopes ...... 181 slopes ...... 105 54D—Libeg gravelly loam, 8 to 15 percent 82F—Elve gravelly loam, 35 to 60 percent slopes ...... 126 slopes ...... 105 54E—Libeg gravelly loam, 15 to 35 percent 83D—Crow clay loam, 4 to 15 percent slopes ...... 126 slopes ...... 84 58B—Coben loam, 0 to 4 percent slopes ...... 74 83E—Crow clay loam, 15 to 35 percent 58C—Coben loam, 4 to 8 percent slopes ...... 75 slopes ...... 85 58D—Coben loam, 8 to 15 percent slopes ...... 75 84D—Helmville cobbly loam, 8 to 15 percent 60B—Quigley loam, 0 to 4 percent slopes ...... 156 slopes ...... 119 60C—Quigley loam, 4 to 8 percent slopes ..... 157 84E—Helmville cobbly loam, 15 to 35 percent 60D—Quigley loam, 8 to 15 percent slopes ...... 119 slopes ...... 157 84F—Helmville cobbly loam, 35 to 60 percent 63C—Quigley-Straw-Water complex, 2 to 8 slopes ...... 120 percent slopes ...... 158 85D—Loberg gravelly loam, 4 to 15 percent 63E—Quigley-Straw-Water complex, 8 to 25 slopes ...... 130 percent slopes ...... 158 85E—Loberg gravelly loam, 15 to 35 percent 65C—Tanna loam, 4 to 8 percent slopes ...... 194 slopes ...... 130 65D—Tanna loam, 8 to 15 percent slopes ...... 195 86D—Winkler gravelly loam, 8 to 15 percent 69C—Boxwell loam, 4 to 8 percent slopes ...... 52 slopes ...... 232 69D—Boxwell loam, 8 to 15 percent slopes ..... 53 86E—Winkler gravelly loam, 15 to 35 percent 69E—Boxwell loam, 15 to 35 percent slopes ... 53 slopes ...... 232 71C—Winfall gravelly loam, 2 to 8 percent 86F—Winkler gravelly loam, 35 to 60 percent slopes ...... 228 slopes ...... 232 71E—Winfall gravelly loam, 8 to 25 percent 86G—Winkler gravelly loam, 60 to 80 percent slopes ...... 228 slopes ...... 233 xvii
87D—Danaher loam, 4 to 15 percent 98E—Trapps gravelly loam, 15 to 35 percent slopes ...... 89 slopes ...... 204 87E—Danaher loam, 15 to 35 percent 98F—Trapps gravelly loam, 35 to 60 percent slopes ...... 89 slopes ...... 204 88E—Whitecow gravelly loam, dry, 15 to 35 99D—Bignell gravelly clay loam, 8 to 15 percent slopes ...... 217 percent slopes ...... 39 88F—Whitecow gravelly loam, dry, 35 to 60 99E—Bignell gravelly clay loam, 15 to 35 percent slopes ...... 217 percent slopes ...... 40 88G—Whitecow gravelly loam, dry, 60 to 80 99F—Bignell gravelly clay loam, 35 to 60 percent slopes ...... 217 percent slopes ...... 40 90F—Mocmont very gravelly loam, moist, 100—Rubble land-Rock outcrop complex ...... 173 35 to 60 percent slopes ...... 139 102—Pits, gravel ...... 153 91E—Rittel loam, 15 to 35 percent slopes...... 166 103—Dumps, mine ...... 100 92E—Whitore gravelly loam, 15 to 35 104A—Fluvaquentic Endoaquolls-Slickens percent slopes ...... 222 complex, 0 to 2 percent slopes, severely 92F—Whitore gravelly loam, 35 to 60 impacted ...... 115 percent slopes ...... 222 105A—Slickens-Fluvaquentic Endoaquolls 93E—Tigeron very gravelly loam, 15 to 35 complex, 0 to 2 percent slopes, severely percent slopes ...... 201 impacted ...... 192 93F—Tigeron very gravelly loam, 35 to 60 109—Bohnly silt loam, 0 to 2 percent slopes .... 51 percent slopes ...... 202 10A—Mccabe-Canarway complex, impacted, 95D—Yreka gravelly loam, 8 to 15 percent 0 to 2 percent slopes, occasionally slopes ...... 247 flooded ...... 136 95E—Yreka gravelly loam, 15 to 35 percent 110—Carten-Wetsand complex, 0 to 2 percent slopes ...... 247 slopes, rarely flooded ...... 65 95F—Yreka gravelly loam, 35 to 60 percent 131E—Varney cobbly clay loam, 15 to 35 slopes ...... 248 percent slopes ...... 211 96D—Worock gravelly loam, cool, 8 to 15 131F—Varney cobbly clay loam, 35 to 50 percent slopes ...... 240 percent slopes ...... 211 96E—Worock gravelly loam, cool, 15 to 35 132B—Beaverell cobbly loam, to 4 percent percent slopes ...... 240 slopes ...... 37 96F—Worock gravelly loam, cool, 35 to 60 132C—Beaverell cobbly loam, 4 to 8 percent percent slopes ...... 240 slopes ...... 38 97D—Evaro gravelly loam, dry, 4 to 15 135B—Baggs sandy loam, 0 to 4 percent percent slopes ...... 110 slopes ...... 35 97E—Evaro gravelly loam, dry, 15 to 35 135C—Baggs sandy loam, 4 to 8 percent percent slopes ...... 110 slopes ...... 35 97F—Evaro gravelly loam, dry, 35 to 60 135D—Baggs sandy loam, 8 to 15 percent percent slopes ...... 111 slopes ...... 35 xviii
136E—Varney-Con complex, 15 to 35 171C—Winfall-Rumblecreek gravelly loams, percent slopes ...... 212 2 to 8 percent slopes...... 229 137B—Sixbeacon cobbly loam, 0 to 4 percent 171E—Winfall-Rumblecreek gravelly loams, slopes ...... 190 8 to 25 percent slopes...... 230 137C—Sixbeacon cobbly loam, 4 to 8 percent 171F—Winfall-Rumblecreek gravelly loams, slopes ...... 190 25 to 50 percent slopes ...... 230 137D—Sixbeacon cobbly loam, 8 to 15 179E—Ambrant-Rochester complex, 15 to 35 percent slopes ...... 190 percent slopes ...... 28 146D—Roy cobbly loam, 8 to 15 percent 179F—Ambrant-Rochester complex, 35 to 60 slopes ...... 169 percent slopes ...... 29 146E—Roy cobbly loam, 15 to 35 percent 180F—Ovando-Elkner complex, 35 to 60 slopes ...... 170 percent slopes ...... 144 149B—Danvers cobbly clay loam, 0 to 4 184E—Helmville cobbly loam, moist, 15 to 35 percent slopes ...... 92 percent slopes ...... 120 149C—Danvers cobbly clay loam, 4 to 8 184F—Helmville cobbly loam, moist, 35 to 60 percent slopes ...... 93 percent slopes ...... 120 149D—Danvers cobbly clay loam, 8 to 15 185E—Relyea-Helmville complex, 15 to 35 percent slopes ...... 93 percent slopes ...... 163 151C—Shawmut cobbly loam, 4 to 8 percent 185F—Relyea-Helmville complex, 35 to 60 slopes ...... 182 percent slopes ...... 164 151D—Shawmut cobbly loam, 8 to 15 190E—Mocmont very gravelly loam, 15 to 35 percent slopes ...... 182 percent slopes ...... 139 151E—Shawmut cobbly loam, 15 to 35 190F—Mocmont very gravelly loam, 35 to 60 percent slopes ...... 183 percent slopes ...... 139 151F—Shawmut cobbly loam, 35 to 60 195E—Yreka gravelly loam, cool, 15 to 35 percent slopes ...... 183 percent slopes ...... 248 152B—Clasoil sandy loam, 0 to 4 percent 195F—Yreka gravelly loam, cool, 35 to 60 slopes ...... 70 percent slopes ...... 248 152C—Clasoil sandy loam, 4 to 8 percent 196E—Worock-Loberg complex, 15 to 35 slopes ...... 70 percent slopes ...... 241 152D—Clasoil sandy loam, 8 to 15 percent 196F—Worock-Loberg complex, 35 to 60 slopes ...... 71 percent slopes ...... 241 168C—Dolus-Boxwell complex, 4 to 8 percent 197D—Evaro gravelly loam, 4 to 15 percent slopes ...... 96 slopes ...... 111 168D—Dolus-Boxwell complex, 8 to 15 percent 197E—Evaro gravelly loam, 15 to 35 percent slopes ...... 96 slopes ...... 112 168E—Dolus-Boxwell complex, 15 to 35 197F—Evaro gravelly loam, 35 to 60 percent percent slopes ...... 97 slopes ...... 112 169F—Doney-Dolus channery loams, 15 to 45 198E—Trapps-Yreka stony loams, 8 to 25 percent slopes ...... 99 percent slopes ...... 204 xix
199E—Bignell gravelly clay loam, cool, 15 to 268F—Dolus-Castner channery loams, 15 to 35 percent slopes...... 40 45 percent slopes...... 97 199F—Bignell gravelly clay loam, cool, 35 to 271C—Rumblecreek-Water complex, 2 to 8 60 percent slopes...... 41 percent slopes ...... 174 200E—Braziel-Tolbert-Rock outcrop complex, 271E—Rumblecreek-Water complex, 8 to 25 15 to 35 percent slopes ...... 55 percent slopes ...... 174 200F—Braziel-Tolbert-Rock outcrop complex, 271F—Rumblecreek-Water complex, 25 to 50 35 to 60 percent slopes ...... 55 percent slopes ...... 175 236B—Varney sandy clay loam, 2 to 4 279E—Ambrant, cool-Rochester, cool- percent slopes ...... 212 Rock outcrop complex, 15 to 35 percent 236C—Varney sandy clay loam, 4 to 8 slopes ...... 29 percent slopes ...... 213 279F—Ambrant, cool-Rochester, cool- 236D—Varney sandy clay loam, 8 to 15 Rock outcrop complex, 35 to 60 percent percent slopes ...... 213 slopes ...... 30 237B—Sixbeacon gravelly loam, 0 to 4 280E—Comad-Elkner-Rock outcrop complex, percent slopes ...... 191 15 to 35 percent slopes ...... 76 237C—Sixbeacon gravelly loam, 4 to 8 280F—Comad-Elkner-Rock outcrop complex, percent slopes ...... 191 35 to 60 percent slopes ...... 77 241B—Perma stony loam, 0 to 4 percent 283D—Crow clay loam, moist, 4 to 15 percent slopes ...... 148 slopes ...... 85 241C—Perma stony loam, 4 to 8 percent 283E—Crow clay loam, moist, 15 to 35 slopes ...... 149 percent slopes ...... 85 241D—Perma stony loam, 8 to 15 percent 298D—Trapps channery loam, 4 to 25 slopes ...... 149 percent slopes ...... 205 241E—Perma stony loam, 15 to 35 percent 298F—Trapps channery loam, 25 to 60 slopes ...... 149 percent slopes ...... 205 242C—Braziel-Perma gravelly loams, 4 to 8 298G—Trapps channery loam, 60 to 80 percent slopes ...... 56 percent slopes ...... 206 242D—Braziel gravelly loam, 8 to 15 percent 299E—Bignell-Yreka complex, 15 to 35 slopes ...... 56 percent slopes ...... 41 242E—Braziel gravelly loam, 15 to 35 percent 299F—Bignell-Yreka complex, 35 to 60 slopes ...... 56 percent slopes ...... 41 251D—Shawmut stony loam, 0 to 15 percent 331B—Varney clay loam, 0 to 4 percent slopes ...... 183 slopes, impacted ...... 213 251E—Shawmut stony loam, 15 to 35 332B—Beaverell loam, 0 to 4 percent percent slopes ...... 184 slopes ...... 38 265C—Tanna-Boxwell loams, 4 to 8 percent 336B—Varney-Anaconda loams, 0 to 4 slopes ...... 195 percent slopes, impacted ...... 214 265D—Tanna-Boxwell loams, 8 to 15 percent 336C—Varney-Anaconda loams, 4 to 8 slopes ...... 195 percent slopes, impacted ...... 214 xx
338C—Perma cobbly loam, 4 to 8 percent 385E—Loberg gravelly loam, moist, 15 to 35 slopes ...... 150 percent slopes ...... 131 338D—Perma cobbly loam, 8 to 15 percent 387E—Danaher-Loberg complex, 15 to 35 slopes ...... 150 percent slopes ...... 89 338E—Perma cobbly loam, 15 to 35 percent 395D—Rumblecreek gravelly loam, 8 to 15 slopes ...... 150 percent slopes ...... 175 338F—Perma cobbly loam, 35 to 60 percent 395E—Rumblecreek gravelly loam, 15 to 35 slopes ...... 151 percent slopes ...... 175 342D—Braziel stony loam, 8 to 15 percent 395F—Rumblecreek gravelly loam, 35 to 60 slopes ...... 57 percent slopes ...... 176 342E—Braziel stony loam, 15 to 35 percent 396D—Worock gravelly loam, 8 to 15 percent slopes ...... 57 slopes ...... 242 342F—Braziel stony loam, 35 to 60 percent 396E—Worock gravelly loam, 15 to 35 slopes ...... 58 percent slopes ...... 242 351E—Roy-Shawmut-Danvers complex, 15 to 396F—Worock gravelly loam, 35 to 60 35 percent slopes ...... 170 percent slopes ...... 242 351F—Roy-Shawmut-Danvers complex, 35 to 399E—Bignell-Yreka complex, cool, 15 to 35 60 percent slopes ...... 171 percent slopes ...... 42 352B—Martinsdale cobbly loam, 0 to 4 399F—Bignell-Yreka complex, cool, 35 to 60 percent slopes ...... 135 percent slopes ...... 42 352E—Martinsdale cobbly loam, 15 to 35 432—Carten loam, 0 to 4 percent slopes, percent slopes ...... 135 rarely flooded ...... 65 371C—Wildgen-Yreka gravelly loams, 2 to 8 434—Gregson loam, cool, 0 to 4 percent percent slopes ...... 223 slopes, rarely flooded ...... 117 371E—Wildgen-Yreka gravelly loams, 8 to 25 435—Saypo loam, cool, 0 to 4 percent slopes, percent slopes ...... 224 rarely flooded ...... 177 371F—Wildgen-Yreka gravelly loams, 25 to 442D—Braziel-Tolbert complex, 8 to 15 50 percent slopes ...... 224 percent slopes ...... 58 379E—Ambrant-Rochester-Rock outcrop 442E—Braziel-Tolbert complex, 15 to 35 complex, 15 to 35 percent slopes ...... 30 percent slopes ...... 58 379F—Ambrant-Rochester-Rock outcrop 442F—Braziel-Tolbert complex, 35 to 60 complex, 35 to 60 percent slopes ...... 31 percent slopes ...... 59 382D—Elve gravelly loam, warm, 8 to 15 444—Gregson loam, 0 to 4 percent slopes, percent slopes ...... 106 rarely flooded ...... 117 382E—Elve gravelly loam, warm, 15 to 35 445—Saypo loam, 0 to 4 percent slopes, percent slopes ...... 106 rarely flooded ...... 177 382F—Elve gravelly loam, warm, 35 to 60 446B—Danvers-Roy complex, 0 to 4 percent percent slopes ...... 106 slopes ...... 93 385D—Loberg gravelly loam, moist, 4 to 15 446C—Danvers-Roy complex, 4 to 8 percent percent slopes ...... 130 slopes ...... 94 xxi
446D—Danvers-Roy complex, 8 to 15 percent 534—Gregson loam, cool, 0 to 4 percent slopes ...... 94 slopes ...... 117 451E—Shawmut very bouldery loam, 8 to 25 535—Saypo loam, cool, 0 to 4 percent percent slopes ...... 184 slopes ...... 178 451F—Shawmut very bouldery loam, 25 to 542E—Perma very bouldery loam, 8 to 25 50 percent slopes ...... 184 percent slopes ...... 151 452D—Hoyt loam, 8 to 15 percent slopes ...... 122 542F—Perma very bouldery loam, 25 to 50 452E—Hoyt loam, 15 to 35 percent slopes..... 122 percent slopes ...... 152 460C—Quigley cobbly loam, 4 to 8 percent 544—Gregson loam, 0 to 4 percent slopes .... 118 slopes ...... 159 545—Saypo loam, 0 to 4 percent slopes ...... 178 479B—Baggs sandy loam, cool, 0 to 4 percent 547—Kleinschmidt gravelly loam, cool, 0 to 4 slopes ...... 36 percent slopes ...... 124 482E—Elve gravelly loam, dry, 15 to 35 549—Marcott silty clay loam, 0 to 4 percent percent slopes ...... 107 slopes ...... 132 482F—Elve gravelly loam, dry, 35 to 60 551F—Shawmut extremely bouldery loam, percent slopes ...... 107 8 to 50 percent slopes...... 185 485E—Relyea-Helmville complex, moist, 552C—Clasoil-Crackerville complex, 4 to 8 15 to 35 percent slopes ...... 164 percent slopes ...... 71 485F—Relyea-Helmville complex, moist, 552D—Clasoil-Crackerville complex, 8 to 15 35 to 60 percent slopes ...... 165 percent slopes ...... 72 486D—Tevis gravelly loam, 4 to 15 percent 552E—Clasoil-Crackerville complex, 15 to 35 slopes ...... 199 percent slopes ...... 72 486E—Tevis gravelly loam, 15 to 35 percent 557—Kleinschmidt gravelly loam, 0 to 4 slopes ...... 200 percent slopes ...... 124 486F—Tevis gravelly loam, 35 to 60 percent 562—Carten loam, 0 to 4 percent slopes ...... 66 slopes ...... 200 580E—Comad-Elkner complex, 15 to 35 488E—Whitecow gravelly loam, cool, 15 to percent slopes ...... 77 35 percent slopes ...... 218 580F—Comad-Elkner complex, 35 to 60 488F—Whitecow gravelly loam, cool, 35 to percent slopes ...... 78 60 percent slopes ...... 218 596D—Worock, cool-Loberg complex, 8 to 15 488G—Whitecow gravelly loam, cool, 60 to percent slopes ...... 243 80 percent slopes ...... 218 596E—Worock, cool-Loberg complex, 15 to 499D—Bignell, cool-Yreka complex, 8 to 15 35 percent slopes ...... 243 percent slopes ...... 43 596F—Worock, cool-Loberg complex, 35 to 499E—Bignell, cool-Yreka complex, 15 to 35 60 percent slopes ...... 244 percent slopes ...... 43 599D—Silverchief-Trapps complex, 8 to 15 499F—Bignell, cool-Yreka complex, 35 to 60 percent slopes ...... 188 percent slopes ...... 44 599E—Silverchief-Trapps complex, 15 to 35 532—Carten loam, cool, 0 to 4 percent percent slopes ...... 188 slopes ...... 66 632—Bushong loam, 0 to 4 percent slopes ...... 62 xxii
634—Blossberg loam, 0 to 4 percent 780E—Ovando-Elkner-Rock outcrop complex, slopes ...... 49 15 to 35 percent slopes ...... 144 635—Tetonview loam, 0 to 4 percent 780F—Ovando-Elkner-Rock outcrop complex, slopes ...... 197 35 to 60 percent slopes ...... 145 637—Poronto loam, 0 to 4 percent 786D—Winkler gravelly loam, cool, 8 to 15 slopes ...... 154 percent slopes ...... 233 642E—Perma extremely bouldery loam, 8 to 786E—Winkler gravelly loam, cool, 15 to 35 50 percent slopes ...... 152 percent slopes ...... 234 649—Turrah silty clay loam, 0 to 4 percent 786F—Winkler gravelly loam, cool, 35 to 60 slopes ...... 207 percent slopes ...... 234 651C—Shawmut-Winspect-Water complex, 786G—Winkler gravelly loam, cool, 60 to 80 2 to 8 percent slopes...... 185 percent slopes ...... 234 651E—Shawmut-Winspect-Water complex, 788F—Whitecow, cool-Rock outcrop complex, 8 to 25 percent slopes...... 186 35 to 60 percent slopes ...... 219 651F—Shawmut-Winspect-Water complex, 799D—Bignell-Yreka-Crow complex, 8 to 15 25 to 50 percent slopes ...... 186 percent slopes ...... 46 680F—Comad-Rubble land complex, 35 to 60 799E—Bignell-Yreka-Crow complex, 15 to 35 percent slopes ...... 78 percent slopes ...... 46 682E—Elve bouldery sandy loam, 8 to 25 824E—Con-Sixbeacon cobbly loams, 15 to 35 percent slopes ...... 108 percent slopes ...... 81 682F—Elve bouldery sandy loam, 25 to 50 824F—Con-Sixbeacon cobbly loams, 35 to 60 percent slopes ...... 108 percent slopes ...... 81 696E—Worock gravelly loam, dry, 15 to 35 832—Bushong loam, 0 to 4 percent slopes, percent slopes ...... 244 rarely flooded ...... 62 696F—Worock gravelly loam, dry, 35 to 60 834—Blossberg loam, 0 to 4 percent slopes, percent slopes ...... 245 rarely flooded ...... 50 699D—Bignell gravelly loam, 8 to 15 percent 835—Tetonview loam, 0 to 4 percent slopes, slopes ...... 44 rarely flooded ...... 198 699E—Bignell gravelly loam, 15 to 35 percent 837—Poronto loam, 0 to 4 percent slopes, slopes ...... 45 rarely flooded ...... 155 699F—Bignell gravelly loam, 35 to 60 percent 838E—Perma-Whitlash-Rock outcrop slopes ...... 45 complex, 15 to 35 percent slopes ...... 152 735—Tetonview-Blossberg loams, 0 to 4 838F—Perma-Whitlash-Rock outcrop percent slopes, rarely flooded...... 197 complex, 35 to 60 percent slopes ...... 153 742E—Braziel-Perma-Water complex, 8 to 25 839E—Windham-Lap gravelly loams, 15 to percent slopes ...... 59 35 percent slopes ...... 226 742F—Braziel-Perma-Water complex, 25 to 50 839F—Windham-Lap gravelly loams, 35 to percent slopes ...... 60 60 percent slopes ...... 227 752E—Clasoil-Crackerville-Rock outcrop 845D—Redchief-Copenhaver gravelly loams, complex, 15 to 35 percent slopes ...... 73 8 to 15 percent slopes...... 161 xxiii
845E—Redchief-Copenhaver gravelly loams, 983D—Crow-Bignell complex, 8 to 15 percent 15 to 35 percent slopes ...... 161 slopes ...... 87 846D—Roy-Tolbert complex, 8 to 15 percent 983E—Crow-Bignell complex, 15 to 35 percent slopes ...... 171 slopes ...... 87 846E—Roy-Tolbert complex, 15 to 35 percent 988F—Whitecow-Rock outcrop complex, slopes ...... 172 35 to 60 percent slopes ...... 219 846F—Roy-Tolbert complex, 35 to 60 percent 988G—Whitecow-Rock outcrop complex, slopes ...... 172 60 to 80 percent slopes ...... 220 854D—Libeg-Monad-Copenhaver complex, 995E—Yreka-Rock outcrop complex, 15 to 8 to 15 percent slopes...... 127 35 percent slopes ...... 249 854E—Libeg-Monad-Copenhaver complex, 995F—Yreka-Rock outcrop complex, 35 to 15 to 35 percent slopes ...... 127 60 percent slopes ...... 249 854F—Libeg-Monad-Copenhaver complex, 996E—Worock-Rock outcrop complex, 15 to 35 to 60 percent slopes ...... 128 35 percent slopes ...... 245 883E—Crow-Bignell complex, moist, 8 to 25 996F—Worock-Rock outcrop complex, 35 to percent slopes ...... 86 60 percent slopes ...... 246 883F—Crow-Bignell complex, moist, 25 to 50 999D—Bignell-Rumblecreek complex, 8 to 15 percent slopes ...... 86 percent slopes ...... 47 886E—Winkler-Rubble land-Rock outcrop 999E—Bignell-Rumblecreek complex, 15 to 35 complex, 15 to 35 percent slopes ...... 235 percent slopes ...... 47 886F—Winkler-Rubble land-Rock outcrop 999F—Bignell-Rumblecreek complex, 35 to 60 complex, 35 to 60 percent slopes ...... 235 percent slopes ...... 48 886G—Winkler-Rubble land-Rock outcrop DUMPS—Dumps, sanitary landfill ...... 100 complex, 60 to 80 percent slopes ...... 236 M-W—Miscellaneous Water ...... 137 982F—Elve-Rock outcrop complex, 35 to 60 W—Water ...... 215 percent slopes ...... 108 xxiv
Summary of Tables
Temperature and precipitation ...... 9
Freeze dates in spring and fall ...... 10
Growing season ...... 11
For tables with the most current data, please visit the Soil Data Mart at http://soildatamart.nrcs.usda.gov/. xxvii
Foreword
This soil survey contains information that affects land use planning in this survey area. It contains predictions of soil behavior for selected land uses. The survey also highlights limitations and hazards inherent in the soil. This soil survey is designed for many different users. Farmers, ranchers, foresters, and agronomists can use it to evaluate the potential of the soil and the management needed for maximum food and fiber production. Planners, community officials, engineers, developers, builders, and home buyers can use the survey to plan land use, select sites for construction, and identify special practices needed to ensure proper performance. Conservationists, teachers, students, and specialists in recreation, wildlife management, waste disposal, and pollution control can use the survey to help them understand, protect, and enhance the environment. Various land use regulations of Federal, State, and local governments may impose special restrictions on land use or land treatment. The information in this report is intended to identify soil properties that are used in making various land use or land treatment decisions. Statements made in this report are intended to help the land users identify and reduce the effects of soil limitations on various land uses. The landowner or user is responsible for identifying and complying with existing laws and regulations. Great differences in soil properties can occur within short distances. Some soils are seasonally wet or subject to flooding. Some are shallow to bedrock. Some are too unstable to be used as a foundation for buildings or roads. Clayey or wet soils are poorly suited to use as septic tank absorption fields. A high water table makes a soil poorly suited to basements or underground installations. These and many other soil properties that affect land use are described in this soil survey. The location of each soil is shown on the detailed soil maps. Each soil in the survey area is described. Information on specific uses is given for each soil. Help in using this publication and additional information are available at local offices of the Natural Resources Conservation Service or the Cooperative Extension Service.
Dave White State Conservationist Natural Resources Conservation Service 1
Soil Survey of Powell County Area, Montana
Fieldwork by Brian D. Dougherty, Frank Gariglio III, Arnie Irwin, Huey Long, George A. Rolfes, and Neal Svendsen, Natural Resources Conservation Service
United States Department of Agriculture, Natural Resources Conservation Service, in cooperation with the Montana Agricultural Experiment Station
POWELL COUNTY AREA is located in southwestern Montana (fig. 1). Powell County is bounded on the north by Flathead County, on the west by Missoula and Granite Counties, on the south by Deer Lodge and Jefferson Counties, and on the east by Lewis and Clark County. The Continental Divide runs adjacent to the eastern border of Powell County. The survey area includes 852,500 acres and covers approximately 2,337 square miles. National forest areas within Powell County were not included in this survey. Deer Lodge, the county seat, is located in the south-central part of the county. The survey area’s residents are dependent on the area’s natural resources for most of their livelihood. Figure 1.—Location of Powell County Area, Montana. Ranching and farming, timber harvesting, and mining rely on the wealth of the geology, soil, and water of the region. History Elevation ranges from 3,500 to 8,600 feet. Mean annual precipitation ranges from 10 to 40 inches, In July 1806, Meriwether Lewis and nine members and mean annual temperature ranges from 34 to of his expedition crossed the northern part of the 42 degrees F. The growing season ranges from 30 to survey area. They became the first documented 105 days. people of European descent to visit this area. The first discovery of gold in Montana occurred in General Nature of the Survey Area the 1850s at Gold Creek. The lure of precious metals brought a rapid influx of prospectors, miners, and This section describes some of the environmental fortune seekers to the survey area. Others who were and cultural features that affect the use and willing to test the merits of additional business management of soils in the survey area. These activities also arrived. features are history; industry, transportation, and Shortly after World War I, the mining boom came recreation; physiography and drainage; geologic to a halt, and many marginal mining operations shut history and regional geology; geologic units; mineral down. Some people left the area while others resources; ground-water resources; seismic activity; remained and began ranching, developing their and climate. holdings, and establishing permanent homes. 2 Soil Survey
Ranching development accompanied the growth of The Powell County Area provides numerous mining activities. At first, industry was limited to opportunities for outdoor recreation. Antelope, elk, production that could be consumed locally. The mule deer, and white-tailed deer are abundant and Mullan Road, a military road connecting the Missouri offer excellent big-game hunting. Camping, fishing, River transportation facilities at Fort Benton, and water recreation activities can be found along the Montana, to the military outpost at Walla Walla, Blackfoot, Little Blackfoot, and Clark Fork Rivers. Washington, provided the only access to the mining Numerous small lakes, ponds, and smaller streams towns until the establishment of the Northern Pacific provide good fishing. Railway in 1883. In 1863, Johnny Grant started a ranch in the Deer Lodge Valley; Conrad Kohrs later owned it. The Grant-Kohrs Ranch became one of the Physiography and Drainage nation’s largest and best-known 19th century range Mary Marshall Garsjo, State Geologist, Natural Resources ranches and is now a national historic site. Conservation Service, prepared the Geology section. Today ranching, as well as some mining and forest industries, supports the economy of the survey area. The Powell County Area is located near the center of the physiographic province of the Northern Rocky Industry, Transportation, and Recreation Mountains. The rugged, mountainous terrain of the Flint Creek Range to the southwest and the relatively Raising livestock, growing forage crops, and low, rounded mountains of the Garnet Range to the producing timber are the principal industries in the east characterize the survey area. The Deer Lodge survey area. Also of importance is the mining of Valley separates the ranges with its broad benches phosphate and precious metals. Cow-calf operations sloping toward the flood plain of the Clark Fork River. account for nearly 85 percent of farm income. Barley, In the northeastern and eastern sections of the oats, spring wheat, and winter wheat are generally county, the Continental Divide forms 60 miles of the grown in rotation with forage crops. Small grains are border. mainly used for feed grain. Alfalfa grass-hay and The Garnet Range trends west-northwest across certified seed potatoes are grown on irrigated land. the northern half of the survey area. The upper Public stockyards at the nearby towns of Butte and surface of the Garnet Range is an ancient plateau; Missoula provide ranchers with good livestock there are only a few hundred feet of relief in the marketing facilities. Some cattle are sold directly from range’s upper elevations. The Garnet Range contains the ranch to feeder buyers. several isolated topographic highs, including Devil In the north-central part of the Powell County Area, Mountain with an elevation of 7,438 feet above sea State Highway 200 runs west and east through level. Ovando. East of Ovando, State Highway 141 joins The Flint Creek Range is a rugged north-south State Highway 200. State Highway 141 then runs trending feature located on the southwestern margin southeast near Helmville, joining U.S. Highway 12 at of the survey area. The Flint Creek Range is much Avon. U.S. Highway 12 runs mainly east and west more dissected than the Garnet Range and has a from the summit of McDonald Pass, in the maximum relief of 4,000 feet. In the Powell County northeastern corner of the survey area, to its merger Area, the range’s highest peak is Mount Powell, with with Interstate Highway 90 at Garrison. Interstate an elevation of 10,300 feet. Highway 90 exits the county line just west of the Jens The Lewis and Clark Range extends into the exit, northwest of Garrison. Interstate Highway 90 northern tip of Powell County but was not included in runs north and south through the town of Deer Lodge the survey area. Areas within the survey area that from the Jens exit on the northern end of the county were not mapped include Beaverhead National to the Racetrack exit on the southern. Forestlands in the southwestern portion, Helena Numerous secondary roads exist throughout the National Forestlands in the eastern portion, and county. A daily bus service is available to most Lewis and Clark National Forestlands in the northern communities. Railroads join at Garrison and run portion. mainly parallel with Interstate Highway 90 and U.S. The Clark Fork River, which parallels Interstate Highway 12 through Avon. Burlington Northern and Highway 90 north through the survey area and Santa Fe, Montana Rail Link, and Montana Western eventually drains into the Columbia River, drains the are the principal railroads providing traffic through the survey area. Tributaries enter the Clark Fork drainage county. Powell County airport is located just west of from the Flint Creek, Lewis and Clark, and Garnet Deer Lodge. Ranges. The Little Blackfoot River and its tributaries Powell County Area, Montana—Part I 3
drain the east-central portion of the survey area, compressional forces, which initiated the uplift of the joining the Clark Fork River at Garrison. Rocky Mountains. This compression caused large- scale folding and faulting throughout the entire Geologic History and Regional Geology region. Thrusting was completed by about 75-million years Characteristic of the Rocky Mountains, the survey ago (Ruppel, 1984). Thrusting was followed by area has had an extremely complex geologic history, widespread episodes of plutonism and volcanism that which has been greatly simplified here. Because of continued throughout Cretaceous and early-Tertiary the mineral deposits within the survey area, it has time into the Eocene. During the later stages of thrust been mapped and studied extensively. faulting, melting within the lower crust or upper The geologic history of the Powell County Area mantle created masses of magma that rose toward began as the earth’s crust cooled in the Archean Eon the surface. As the magma rose, it metamorphosed of the Precambrian Age. Geologists believe that the the surrounding country rock. Hydrothermal activity earth was formed approximately 4.5-billion years ago. associated with these intrusions formed a variety of In the vast amount of time that has passed since mineral deposits. then, most of these ancient rocks have been buried Numerous plutons were emplaced in the Powell and recrystallized, obscuring their original textures. County Area during this time, and most have a Age dates on the Archean rocks of Montana show granitic composition. The largest pluton is the Boulder that most of them recrystallized about 2.7-billion Batholith, which is composed of several coalesced years ago. plutons and surrounded by other isolated plutons of About 1.5-billion years ago, a very thick sequence varying composition. [Plutons are igneous intrusions of sediments, known as the Belt Supergroup, began of any size. Batholiths are igneous intrusions with a to accumulate in what are now western Montana, surface exposure of greater than 40 square miles northern Idaho, and southern British Columbia. (100 square kilometers).] Radiometric dating has Vegetation had not yet developed on the continents, shown that the entire intrusive assemblage was so erosion was extensive. Vast amounts of sediment emplaced over a 10-million-year time span, starting were deposited into a deep basin that contained approximately 80-million years ago (Smedes and exposed mudflats; small beaches; and shallow, others, 1988). probably brackish, water. Sandstone was deposited Some of the magma rose and erupted on the on beach and near-shore environments; siltstone and surface, forming large fields of volcanic rocks. shale were deposited in lower energy, deeper water Magma from the melt that formed the Boulder environments; and limestone was normally formed in Batholith erupted to form the Elkhorn Mountain warm, shallow water. Volcanics. The Lowland Creek Volcanics were Sediments were deposited in the Belt Basin for at erupted during a later volcanic episode that occurred least 20- to 30-million years, resulting in thousands of 51- to 55-million years ago. feet of accumulated sediments. Over time, the In mid-Tertiary time, regional tectonic forces sediments were metamorphosed by pressure caused shifted from compressional to extensional. This by the weight of the overlying materials as they extensional tectonism led to the development of accumulated. Shale was metamorphosed to argillite, isolated mountain ranges surrounded by broad siltstone to siltite, and sandstone to quartzite. valleys, characteristic of the topography of Alternating periods of deposition and erosion have southwestern Montana. occurred with changing sea levels since Precambrian As the basins began to form, great volumes of time, producing a thick sedimentary sequence of sediment were washed into them from the interbedded sandstone, shale, and limestone. Much surrounding mountains, forming extensive basin-fill of Montana was above sea level for long periods. deposits. Volcanic eruptions blanketed the survey Erosion that occurred during these periods created area with volcanic ash and debris. Sediment disconformities, or gaps, in the geologic record. The accumulated in large basins throughout the Tertiary survey area contains rocks from every geologic Period. period except the Ordovician and Silurian and the The climate, arid throughout most of the Tertiary upper Triassic through mid-Jurassic. Period, affected the character of the basin-fill The prominent structural features visible today deposits. Tropical periods during the mid-Miocene began forming approximately 90-million years ago in Period featured lush vegetation, which prevented the late-Cretaceous period. At that time, a collision widespread erosion; streams carried relatively fine- between major tectonic plates to the west created grained sediment through permanent channels. The 4 Soil Survey
climate changed about 10-million years ago, and the entire sequence is not completely represented land became a desert again. Permanent streams because of regional thrust faulting. The groups became ephemeral, and the character of the present include the Ravalli Group, the Middle Belt sediment changed. Coarser-grained sediments were carbonates, and the Missoula Group. These rocks are laid down in flash-flood deposits that choked stream hard and thinly bedded and consist primarily of channels and spread across the landscape. These limestone, argillite, siltite, and quartzite. They are sediments first filled the valleys, which had been exposed mainly in the northern part of the Garnet created during tropical times, then buried the hills Range. These groups have been subdivided into between them. separate formations. Because of their limited The Quaternary Period has been dominated by exposures in this survey area, they will not be periods of glaciation, volcanism, and continuing discussed separately here. erosion and deposition. During the ice ages of the Pleistocene, alpine glaciers covered the high Paleozoic and Mesozoic Rocks mountain peaks, eroding U-shaped valleys and Paleozoic and Mesozoic sedimentary formations depositing linear moraines and glacial outwash in are exposed in the Flint Creek Range and the many valleys. The Flint Creek Range has been southern part of the Garnet Range. These formations affected by at least three known, separate glacial occur as components within the folded stacks of events. Glaciers extended into the northern tip of sedimentary rocks that make up the imbricated thrust Powell County from the Lewis and Clark Range to the sheets characteristic of this survey area. The north. The Garnet Range was too low in elevation to stratigraphic units are not continuous across broad be affected, and the remainder of the survey area is areas. unglaciated. The last ice age ended approximately Middle Cambrian- to Permian-aged rocks that 10,000 years ago. make up the Paleozoic section consist of thick- The landscape has continued to evolve since the bedded limestone and dolomite, with lesser amounts end of the last ice age, although the changes are not of carbonate-bearing shale and siltstone, and some as dramatic. Today, streams and rivers are reworking sandstone and quartzite. These rocks include a alluvial deposits in the active flood plains. These flood Devonian-aged, highly brecciated, recrystallized plains are subject to overflow from fluctuating water limestone that is petroliferous, commonly exuding a levels during periods of high runoff. Alluvial terraces petroleum odor. Pennsylvanian-aged sandstone, the at higher elevations along the valley floor show Quadrant Quartzite, forms one of the better marker former river levels. These older terraces are no longer beds of the Garnet Range. Pennsylvanian-aged undergoing active deposition and are relatively sandstone is a resistant, relatively pure quartzite that stable. Landslides occur along steep slopes is fine- to medium-grained, white to tan, and vitreous; composed of clayey materials, and they can occur it commonly forms ridges, hogbacks, and cuestas near faults where saturated strata, regardless of rock above the underlying, less resistant shales. Also of type, have been weakened by excessive seepage. interest is the Permian-aged Phosphoria Formation, Ongoing seismic activity indicates that tectonic forces consisting of phosphate-rich, calcareous mudstone are still active in this region. that has been mined in the Garrison region. Triassic- to Upper Cretaceous-aged rocks that Geologic Units make up the Mesozoic section are primarily sandstone and shale with lesser amounts of siltstone, Listed in order of decreasing age, the sequence of thin limestone, and conglomerate. rocks exposed in the survey area is summarized A variety of both intrusive and extrusive rock types below. Formations are defined as a succession of associated with the extensive igneous activity of the strata distinctive enough to constitute a basic unit for late-Cretaceous and early-Tertiary Periods occurs in mapping, identified by similar rock type and the survey area. Mesozoic-aged igneous rocks stratigraphic position. Formations can be combined consist primarily of coarse-grained granitic rocks of into groups or subdivided into members. Systems are the Boulder Batholith. The Boulder Batholith extends the rocks deposited during a particular geologic to the northeast from the Big Hole River near the period. town of Divide and across the Boulder River almost to Precambrian Rocks Helena. It occurs in the southeastern corner of the survey area. The oldest rocks in the survey area were The late-Cretaceous Elkhorn Mountain Volcanics deposited within the Belt Supergroup, although the crop out in a wide, northeast-trending band in the Powell County Area, Montana—Part I 5
southeastern corner of the survey area and in the volcanic ash and tuff and reworked ash that was hills to the east of the Grant-Kohrs Ranch. The eroded off the hills and deposited in the basin fill. volcanics consist of andesitic and basaltic air-fall Some of the units contain bentonite, formed when tuffs, welded tuffs, breccias, and flows. volcanic ash weathers under water. The northern end of the survey area contains Cenozoic Rocks Pleistocene-aged alpine glacial till and outwash fan Cenozoic rocks in the survey area consist of both deposits derived from the Ovando and Placid Creek volcanic rocks and the large thickness of sediments glaciers. These deposits extend south to an area that were deposited in the intermontane basin during approximately 4 miles southwest of the town of Tertiary time. The most recent deposits include Helmville, including the Kleinschmidt Flat area. Other colluvium, alluvium, terrace gravels, and landslide glacial deposits consist primarily of moraine, which is debris, which are currently being deposited and a hummocky, unsorted deposit that covers glaciated reworked. valley bottoms and extends up the adjacent slopes. Volcanic rocks include the flows and pyroclastic Lateral moraines form along the side margins of the deposits associated with Lowland Creek Volcanics glacier as it advances, and terminal moraines form and younger, silica rich-rhyolite flows. The Lowland across the course of a glacier at the point of its Creek Volcanics extend into the extreme furthest advance. One of the most distinctive southeastern corner of the survey area where they moraines in the Flint Creek Range is the Racetrack overlie the Elkhorn Mountain Volcanics and granitic Moraine, located at the southern end of Powell rocks of the Boulder Batholith. These volcanics are County. Other terminal moraines are located at the predominantly of volcanic breccias and mostly valley floor below Dempsey, Tincup Joe, Rock, Mill, rhyolitic flows with interbeds of ash-flow tuffs, welded Pike’s Peak, and Gold Creeks. tuffs, and sedimentary strata. They are over 4,000- Quaternary surficial deposits make up the material feet thick where fully exposed. In some areas, typically found on the valley floors of the survey area sedimentary units contain coal beds up to 6-inches and include terrace gravels, colluvium, alluvium, and thick. landslide deposits. These deposits are generally The Lowland Creek Volcanics can be recognized unconsolidated and relatively thin. Most of these by their fine-grained character and their tendency to deposits are originally of glacial origin and have been weather to angular talus slopes. Coarser-grained reworked and transported by current streams. Recent granitic rock weathers to rounded, bouldery outcrops. alluvium includes both coarse-grained channel In the survey area, Tertiary basin-fill sediments deposits and fine-grained flood plain deposits. Fan occur in the Deer Lodge Valley, on the northeastern deposits and cemented colluvium are near the valley side of the Garnet Mountains, and in the north-central margins. part of the survey area in the Blackfoot River Valley. Tertiary sediments are very thick in the survey area, Mineral Resources reaching a maximum thickness of 10,300 feet in an exploratory drill hole completed in the center of the In 1852, Powell County Area was the site of valley near Deer Lodge. Tertiary strata underlie the Montana’s first placer gold discovery near the mouth high terraces at the margins of the valley. A thin of Gold Creek. The placer deposit at the mouth of veneer of glacial outwash west of the Clark Fork Bear Creek produced more than $7,000,000 in gold River and alluvium near the center of the valley and silver before 1917. The Powell County Area ranks overlay the Tertiary strata. fourth overall in the historical production of placer Tertiary basin fill has been mapped as units of the gold in Montana between 1904 and 1946. Lode Bozeman Group and consists of light-gray to deposits of gold, silver, copper, lead, and zinc were yellowish-brown tuffaceous sandstone containing emplaced with the granodiorite intrusive rocks. These subordinate interbeds of limestone and lenses of deposits include replacement lodes located along the pebble and cobble conglomerate. The sediments vary contact between granodiorite and the Cambrian and widely in both grain size and their degree of Precambrian sedimentary rocks it intruded and in consolidation; individual units grade into and veins within both the intrusive bodies and the country interfinger with each other. Some sediments are rocks they intruded. unconsolidated to semiconsolidated, while some are Commercial phosphate was mined for a number of hard and completely lithified. The sediments are years outside Garrison, near the Clark Fork River. interbedded with both in-place air-fall deposits of These deposits were mined for use in fertilizer; 6 Soil Survey
however, because of fluoride emissions the operation the surface and can occur along small, discontinuous was eventually stopped. Phosphate is currently being faults that do not extend to the surface. mined near Warm Springs Creek. Since 1982, The Earthquake Studies Office of the There are no significant oil and gas prospects Montana Bureau of Mines and Geology has operated located in the survey area at this time. Seven a network of seismographs in western Montana. The exploration holes have previously been drilled in the network is relatively dense around the Butte area to Deer Lodge Valley. Minor lignite deposits are identify any increases in seismicity following flooding contained in the Tertiary sediments around the Rock of the Berkeley Pit and the mines around it. Creek area, southwest of Garrison, and in the area Information provided by the Earthquake Studies near Spotted Dog Creek, west of Elliston. Office shows that there have been hundreds of small earthquakes, with a maximum magnitude of 2.8, Ground-Water Resources recorded in the Butte area since the network began in 1982. Ninety-six earthquakes, with a maximum The main source of ground water in the Deer magnitude of 3.1, were recorded in or near Deer Lodge Valley is the alluvium of the Clark Fork River. Lodge County in this same period. Only three Wells completed in this aquifer are generally shallow, earthquakes had magnitudes greater than 2.5. ranging from 10- to 150-feet deep. The water is Microearthquakes are earthquakes with unconfined, and the water table fluctuates seasonally. magnitudes of 2.0 or less. Microearthquakes are not Overall water quality is suitable for both domestic and commonly felt and are recorded only on local livestock use. Yields range from 5 to 150 gallons per seismographs. Earthquakes with magnitudes under minute (gpm), with an average of about 25 gpm. 4.5 do not generally cause significant damage. Limited irrigation supplies of 200 to 300 gpm can Montana has been divided into earthquake hazard generally be obtained locally from the upper few areas on a scale from five to ten. This designation is hundred feet, and flows to 600 gpm are possible in based on historic earthquake activity and the the Racetrack area. distribution of active faults. The survey contains areas Tertiary basin-fill sediments are the other primary designated as both seven and eight. For comparison, source of water in the Deer Lodge Valley. These the area around Plentywood is designated as a six, sediments are finer grained than the alluvium and and the area around Hebgen Lake is designated as a become more consolidated with depth. Well yields ten. are generally between 15 and 20 gpm, although the city of Deer Lodge is reported to have a 900-gpm well Climate in this deposit. Ground water is confined under artesian conditions; however, few wells flow at the The survey area, located along the western slopes surface. of the Continental Divide, is quite irregular in In the upper elevations of the survey area, ground topography. The area experiences large variations in water reserves are available in bedrock aquifers at far climate within short distances, typical of mountain- greater depths, generally 200 to over 600 feet. valley landscapes. Formations containing limestone and sandstone are Powell County Area has marked seasonal commonly the best producing aquifers. variations, typical of Montana’s counties situated near or along the Continental Divide. A pronounced Seismic Activity difference in precipitation exists between mountain and valley areas. Powell County Area is located on the western edge The valleys are relatively dry during the colder of the intermountain seismic belt, although its seismic months and wetter during late spring and early activity is relatively quiet for this region. The summer. In the valleys, the moist season generally intermountain seismic belt extends from southern occurs during May, June, and July. In the mountains, Nevada north to Flathead Lake and contains most of the wettest part of the year is from midwinter to early the known active faults in Montana, Idaho, Wyoming, spring; however, the average pattern is more and Utah. The intermountain seismic belt is complicated and, as a result, more variable. At high characterized by shallow seismicity, earthquake elevations the wettest periods are fall, winter, and swarms, and normal fault scarps, which show spring. Precipitation during the colder half of the year evidence of Quaternary or historic movement. Small- is often light and steady, sometimes lasting for hours. to moderate-magnitude earthquakes in this seismic During the warmer months, showers and zone occur at depths between 3 and 10 miles below thundershowers dominate precipitation events. Powell County Area, Montana—Part I 7
Winter months in the northern half of the survey Individual soils on the landscape commonly merge area produce cloudy weather. Nearly all winter into one another as their characteristics gradually precipitation falls as snow. Winters are cold, change. To construct an accurate map, however, soil averaging well below freezing. Summers, although scientists must determine the boundaries between warm, seldom produce oppressive heat, and even the the soils. They can observe only a limited number of warmest days (most commonly in the 90-degree soil profiles. Nevertheless, these observations, range) are followed by cool nights. supplemented by an understanding of the soil- Following this section are tables giving data on vegetation-landscape relationship, are sufficient to temperature and precipitation, probable dates of the verify predictions of the kinds of soil in an area and to first freeze in fall and the last freeze in spring, and determine the boundaries. data on length of the growing season. Soil scientists recorded the characteristics of the Growing-degree days, as shown in the soil profiles that they studied. They noted color, “Temperature and Precipitation” table, are equivalent texture, size, and shape of soil aggregates; kind and to heat units. During the month, growing-degree days amount of rock fragments; distribution of plant roots; accumulate by the amount that the average reaction; and other features that enable them to temperature each day exceeds a base temperature identify soils. After describing the soils in the survey (40 degrees F). The normal growing-degree area and determining their properties, soil scientists accumulation is used to schedule single or assigned the soils to taxonomic classes (units). successive plantings of a crop between the last Taxonomic classes are concepts. Each taxonomic freeze in spring and the first freeze in fall. class has a set of soil characteristics with precisely defined limits. The classes are used as a basis for comparison to classify soils systematically. Soil How This Survey Was Made taxonomy, the system of taxonomic classification used in the United States, is based mainly on the This survey was made to provide information kind and character of soil properties and the about the soils and miscellaneous areas in the arrangement of horizons within the profile. After the survey area. This information includes a description soil scientists classified and named the soils in the of the soils and miscellaneous areas and their survey area, they compared the individual soils with location and a discussion of their suitability, similar soils in the same taxonomic class in other limitations, and management for specified uses. Soil areas so that they could confirm data and assemble scientists observed the steepness, length, and shape additional data based on experience and research. of the slopes; the general pattern of drainage; the While a soil survey is in progress, samples of kinds of crops and native plants; and the kinds of some of the soils in the area generally are collected bedrock. They dug many holes to study the soil for laboratory analyses and for engineering tests. Soil profile, which is the sequence of natural layers, or scientists interpret data from these analyses and horizons, in a soil. The profile extends from the tests as well as field-observed characteristics and soil surface down into the unconsolidated material in properties to determine the expected behavior of the which the soil formed. The unconsolidated material is soils under different uses. Interpretations for all of the devoid of roots and other living organisms and has soils are field tested through observation of the soils not been changed by other biological activity. in different uses and under different levels of The soils and miscellaneous areas in the survey management. Some interpretations are modified to fit area are in an orderly pattern that is related to the local conditions, and some new interpretations are geology, landforms, relief, climate, and natural developed to meet local needs. Data are assembled vegetation of the survey area. Each kind of soil and from other sources, such as research information, miscellaneous area is associated with a particular production records, and field experience of kind of landform or with a segment of the landform. specialists. For example, data for crop yields under By observing the soils and miscellaneous areas in high levels of management are modeled and the survey area and relating their position to specific validated with farm records and field or plot segments of the landform, soil scientists develop a information on the same kinds of soil. concept, or model, of how the soils were formed. Predictions about soil behavior are based not only During mapping, this model enables soil scientists to on soil properties but also on such variables as predict with a considerable degree of accuracy the climate and biological activity. Soil conditions are kind of soil or miscellaneous area at a specific predictable over long periods, but they are not location on the landscape. predictable from year to year. For example, soil 8 Soil Survey
scientists can predict with a fairly high degree of roads, and rivers, all of which help in locating accuracy that a given soil will have a high water table boundaries accurately. within certain depths in most years, but they cannot Descriptions, names, and delineations of the soils predict that a high water table will always be at a in this survey area may not fully agree with those of specific level in the soil on a specific date. the soils in adjacent survey areas. Differences result After soil scientists located and identified the from a better knowledge of soils, modifications in significant natural bodies of soil in the survey area, series concepts, or variations in the intensity of they drew the boundaries of these bodies on aerial mapping or in the extent of the soils in the survey photographs and identified each as a specific map areas. unit. Aerial photographs show trees, buildings, fields, Powell County Area, Montana—Part I 9
Temperature and Precipitation
(Recorded in the period 1961-1990 at Deer Lodge, Montana)
______| | | Temperature (Degrees F) | Precipitation (Inches) |______| | | | | | | | | | | | | | 2 Years in 10 | Average | | 2 years in 10 | Average | Month | Average | Average | | Will Have— | Number | | Will Have— | Number | Average | Daily | Daily |Average| | | of |Average| | | of Days | Total | Maximum | Minimum | | Maximum | Minimum | Growing-| | Less | More | With | Snowfall | | | |Temperature|Temperature| Degree | | Than | Than | 0.10 or | | | | | More Than | Less Than | Days* | | | | More | ______| | | | | | | | | | | | | | | | | | | | | | DEER LODGE: | | | | | | | | | | | | | | | | | | | | | | January-----| 31.8 | 9.2 | 20.5 | 53 | -29 | 2 | 0.49 | 0.15 | 0.77 | 1 | 11.0 February----| 37.8 | 14.6 | 26.2 | 58 | -24 | 6 | 0.33 | 0.12 | 0.51 | 0 | 5.3 March------| 44.0 | 19.4 | 31.7 | 66 | -12 | 23 | 0.48 | 0.22 | 0.70 | 1 | 9.1 April------| 54.7 | 25.7 | 40.2 | 78 | 8 | 99 | 0.75 | 0.34 | 1.15 | 2 | 4.9 May------| 63.0 | 32.9 | 48.0 | 83 | 16 | 262 | 1.83 | 1.00 | 2.56 | 5 | 0.4 June------| 71.8 | 40.1 | 56.0 | 90 | 26 | 476 | 1.76 | 0.88 | 2.53 | 5 | 0.2 July------| 80.6 | 43.2 | 61.9 | 94 | 30 | 679 | 1.17 | 0.45 | 1.76 | 3 | 0.0 August------| 80.2 | 42.0 | 61.1 | 96 | 29 | 652 | 1.21 | 0.51 | 1.88 | 4 | 0.0 September---| 69.3 | 33.9 | 51.6 | 90 | 15 | 361 | 1.09 | 0.29 | 1.73 | 3 | 0.1 October-----| 58.3 | 26.2 | 42.2 | 80 | 5 | 142 | 0.63 | 0.23 | 1.00 | 2 | 1.4 November----| 42.4 | 18.2 | 30.3 | 65 | -12 | 21 | 0.42 | 0.19 | 0.63 | 1 | 5.6 December----| 32.8 | 10.5 | 21.6 | 55 | -27 | 4 | 0.43 | 0.20 | 0.63 | 1 | 8.3 | | | | | | | | | | | Yearly: | | | | | | | | | | | Average----| 55.6 | 26.3 | 40.9 | ——— | ——— | ——— | ——— | ——— | ——— | ——— | ——— Extreme----| 100.0 | -40.0 | ——— | 96 | -35 | ——— | ——— | ——— | ——— | ——— | ——— Total------| ——— | ——— | ——— | ——— | ——— | 2,728 | 10.59 | 7.86 | 12.42 | 28 | 46.2 ______| | | | | | | | | | |
* A growing-degree day is a unit of heat available for plant growth. It can be calculated by adding the maximum and minimum daily temperatures, dividing the sum by 2, and subtracting the temperature below which growth is minimal for the principal crops in the area (Threshold: 40.0 degrees F). 10 Soil Survey
Freeze Dates in Spring and Fall
(Recorded in the period 1961-1990 at Deer Lodge, Montana)
______| | Temperature |______Probability | | | | 24 degrees F | 28 degrees F | 32 degrees F | or lower | or lower | or lower ______| | | | | | DEER LODGE: | | | | | | Last freezing temperature | | | in spring: January-July | | | | | | 1 year in 10 later than----| June 7 | July 1 | July 24 | | | 2 years in 10 later than---| May 31 | June 22 | July 16 | | | 5 years in 10 later than---| May 17 | June 7 | July 2 | | | First freezing temperature | | | in fall: August-December | | | | | | 1 year in 10 earlier than--| Sept. 3 | Aug. 26 | Aug. 11 | | | 2 years in 10 earlier than-| Sept. 9 | Aug. 31 | Aug. 16 | | | 5 years in 10 earlier than-| Sept. 20 | Sept. 8 | Aug. 27 ______| | | Powell County Area, Montana—Part I 11
Growing Season
(Recorded in the period 1961-1990 at Deer Lodge, Montana)
______| | Daily Minimum Temperature |______Probability | | | | Higher than | Higher than | Higher than | 24 degrees F | 28 degrees F | 32 degrees F ______| | | | Days | Days | Days | | | DEER LODGE: | | | | | | 9 years in 10------| 95 | 66 | 30 | | | 8 years in 10------| 106 | 75 | 39 | | | 5 years in 10------| 126 | 94 | 57 | | | 2 years in 10------| 146 | 113 | 74 | | | 1 year in 10------| 157 | 123 | 84 ______| | |
13
Formation and Classification of the Soils
This section relates the soils in the survey area to soil. Soils that have cool temperatures and high the major factors of soil formation and describes the precipitation generally contain more organic matter system of soil classification. The tables, and are dark colored. Soils that have warm “Classification of the Soils” and “Acreage and temperatures and low precipitation generally contain Proportionate Extent of the Soils,” at the end of this less organic matter and are light colored. section show the classification and extent of the soils In the survey area, the mean annual precipitation in this survey area. ranges from 11 to 40 inches. The mean annual temperature ranges from 34 to 44 degrees F. Formation of the Soils Living Organisms Soil is a natural, three-dimensional body on the earth’s surface. Soil has properties that result from Living organisms are active in the formation of the integrated effect of climate and living matter soils. Plants, animals, insects, and microorganisms acting on earthy parent material, as conditioned by affect gains or losses in organic matter, plant relief over a period of time. nutrients, and changes in porosity and structure. Although there are many different soils, each soil Roots, rodents, and insects penetrate the soil and is the result of the interaction of the same five factors. alter its structure. Microorganisms, chemicals in the These factors are the effect of climate on the parent soil, and insects change leaves, roots, and entire material, the kinds of plants and organisms living in plants that remain in the surface layer to humus. the soil, the relief of the land, the physical and Fungi and algae also contribute to the decomposition chemical composition of the parent material, and the of bedrock. Animals increase porosity by burrowing length of time it took for the soil to form. through the soil and leaving open channels for the Within short distances, the combination of these movement of water and air. Common rodents in the factors varies, and, consequently, the soils that form survey area are badger, ground squirrel, and rabbit. differ in fertility, productivity, and physical and Vegetation in this survey area consists mainly of chemical characteristics. In the following paragraphs, short grasses, mid grasses, and shrubs in the valleys the factors of soil formation are discussed as they and coniferous forests in the mountains. relate to the soils in the Powell County Area. Topography Climate Topography, or relief, is determined by glaciation Temperature and precipitation mainly determine and mountain formation and by the age and climate, an active force in the formation of soils. In the resistance of geologic formations to erosion by wind Powell County Area, winters are cold; springs are and water. Topography influences soil development cool and moist; and summers are warm and dry. through its effect on drainage and runoff. On the Seasonal weather patterns include arctic cold waves terrace edges of this survey area, runoff water has and gusty warm southwest winds, called Chinooks. carved drainages. These rugged areas contrast Soils form in rocks that have been broken into sharply with the smoother areas of the terrace suitable materials by erosion and alternate freezing surfaces. and thawing. Chemical reactions, such as solution The number and distinctness of soil horizons and hydration, further break down this weathered generally decrease as slope increases. Soils on material. steep slopes with rapid runoff have many Precipitation and temperature affect the kind and characteristics similar to those of soils formed in arid amount of vegetation that grows on the soil. climates. Nearly level to moderately sloping soils Vegetation decays to produce organic matter in the have the characteristics of soils common in the 14 Soil Survey
survey area. Examples of this general principle are The Coben soil formed in parent material that the Sixbeacon soil that is moderately steep or very is similar to that of the Canarway gravelly sandy steep and the Coben soil that is nearly level to loam but is much older. These soils formed in strongly sloping. alluvium on alluvial fans and stream terraces. They contain enough organic matter to have a dark- Parent Material colored A horizon and a distinct clay accumulation in a Bt horizon. Nearly all of the carbonates have been Most of the soils in the survey area formed in leached to a depth of about 23 inches. alluvium derived from mixed sources or from material Many of the sloping and steep, shallow, and very weathered from bedrock. Types of this bedrock shallow soils appear to have been in the process of include andesite, argillite, basalt, granite, limestone, formation for about as long as some of the more quartzite, rhyolite, and sandstone. developed, less sloping soils. However, erosion has Soils, such as the Elve and the Libeg series, that removed the soil as fast as it formed. In this case, the formed in argillites and quartzites are generally effect of time has been offset by the effect of relief. loamy. Soils, such as the Danaher and the Loberg series, that formed in materials weathered from Classification of the Soils igneous rocks are generally clayey. Soils, such as the Ambrant and the Comad series, that formed in The system of soil classification used by the materials weathered from granite are generally sandy. National Cooperative Soil Survey has six categories Soils, such as the Helmville and the Relyea series, (Soil Survey Staff, 1998 and 1999). Beginning with that formed from limestone are clayey or loamy. Soils, the broadest, these categories are the order, such as the Con and the Danvers series, that formed suborder, great group, subgroup, family, and series. in mixed alluvium are either clayey or loamy. Classification is based on soil properties observed in Many soils in the survey area have accumulated the field or inferred from those observations or from lime from the parent material. Lime affects the laboratory measurements. The table, “Classification availability of plant nutrients, especially phosphorus. of the Soils,” shows the classification of the soils in the survey area. The categories are defined in the Time following paragraphs. ORDER. Twelve soil orders are recognized. The Change taking place in soils over a long period is differences among orders reflect the dominant soil- called soil genesis. As a result of these changes, forming processes and the degree of soil formation. distinct horizons, or layers, develop in the soils. The Each order is identified by a word ending in sol. An length of time that parent materials have been in example is Inceptisol, from inceptum, meaning place and exposed to climate and living organisms is beginning. generally reflected in the degree to which the soil SUBORDER. Each order is divided into suborders profile has developed. The kind and arrangement of primarily on the basis of properties that influence soil these horizons are called soil morphology. These genesis and are important to plant growth or layers are described in terms of chemistry, color, properties that reflect the most important variables consistence, permeability, structure, texture, and within the orders. The last syllable in the name of a thickness. suborder indicates the order. An example is Ustept Soils are classified according to their approximate (Ust, meaning burnt, plus ept, from Inceptisol). age, from young to mature. Age, or maturity, of a soil GREAT GROUP. Each suborder is divided into is generally indicated by the thickness and great groups on the basis of close similarities in kind, distinctness of subsurface horizons, content of arrangement, and degree of development of organic matter and clay, depth to which soluble pedogenic horizons; soil moisture and temperature material is leached, and form and distribution of regimes; type of saturation; and base status. Each calcium carbonate and gypsum in the soil. great group is identified by the name of a suborder Young soils show very little profile development. and by a prefix that indicates a property of the soil. Canarway gravelly sandy loam, a soil of the Entisol An example is Haplustepts (Hapl, meaning simple, order, is an example of a young soil. It is on a flood plus ustepts, the suborder of the Inceptisols that have plain adjacent to a stream. The soil contains organic an ustic moisture regime). matter that forms an A horizon; it has little clay SUBGROUP. Each great group has a typic accumulation and little translocation of carbonates subgroup. Other subgroups are intergrades or within the profile. extragrades. The typic subgroup is the central Powell County Area, Montana—Part I 15
concept of the great group; it is not necessarily the biological activity. Among the properties and most extensive. Intergrades are transitions to other characteristics considered are particle-size class, orders, suborders, or great groups. Extragrades have mineralogy class, cation-exchange activity class, soil some properties that are not representative of the temperature regime, soil depth, and reaction class. A great group but do not indicate transitions to any family name consists of the name of a subgroup other taxonomic class. Each subgroup is identified by preceded by terms that indicate soil properties. An one or more adjectives preceding the name of the example is fine-loamy, mixed, superactive, frigid Typic great group. The adjective Typic identifies the Haplustepts. subgroup that typifies the great group. An example is SERIES. The series consists of soils within a family Typic Haplustepts. that have horizons similar in arrangement in the FAMILY. Families are established within a profile, color, consistence, mineral and chemical subgroup on the basis of physical and chemical composition, reaction, structure, and texture. An properties and other characteristics that affect example is the Doney series. The Doney series is a management. Generally, the properties are those of fine-loamy, mixed, superactive, frigid Typic horizons below plow depth where there is much Haplustept. 25
Soil Series and Detailed Soil Map Units
In this section, arranged in alphabetical order, called noncontrasting, or similar, components. They each soil series recognized in the survey area is may or may not be mentioned in a particular map unit described. Each description is followed by the description. Other minor components, however, have detailed soil map units associated with the series. properties and behavioral characteristics divergent Characteristics of the soil and the material in which enough to affect use or to require different it formed are identified for each soil series. A pedon, management. These are called contrasting, or a small three-dimensional area of soil, that is typical dissimilar, components. They generally are in small of the series in the survey area is described. The areas and could not be mapped separately because detailed description of each soil horizon follows of the scale used. Some small areas of strongly standards in the “Soil Survey Manual” (Soil Survey contrasting soils or miscellaneous areas are Division Staff, 1962). Many of the technical terms identified by a special symbol on the maps. The used in the descriptions are defined in “Soil contrasting components are mentioned in the map Taxonomy” (Soil Survey Staff, 1999). Unless unit descriptions. A few areas of minor components otherwise stated, colors in the descriptions are for dry may not have been observed, and, consequently, soil. Following the pedon description is the range of they are not mentioned in the descriptions, especially important characteristics of the soils in the series. where the pattern was so complex that it was The map units delineated on the detailed soil impractical to make enough observations to identify maps in this survey represent the soils or all of the soils and miscellaneous areas on the miscellaneous areas in the survey area. The map unit landscape. descriptions in this section, along with the maps, can The presence of minor components in a map unit be used to determine the suitability and potential of a in no way diminishes the usefulness or accuracy of unit for specific uses. They also can be used to plan the data. The objective of mapping is not to delineate the management needed for those uses. pure taxonomic classes but rather to separate the A map unit delineation on a soil map represents an landscape into landforms or landform segments that area dominated by one or more major kinds of soil or have similar use and management requirements. The miscellaneous areas. A map unit is identified and delineation of such segments on the map provides named according to the taxonomic classification of sufficient information for the development of resource the dominant soils. Within a taxonomic class, there plans. If intensive use of small areas is planned, are precisely defined limits for the properties of the however, onsite investigation is needed to define and soils. On the landscape, however, the soils are locate the soils and miscellaneous areas. natural phenomena, and they have the characteristic An identifying symbol precedes the map unit name variability of all natural phenomena. Thus, the range in the map unit descriptions. Each description of some observed properties may extend beyond the includes general facts about the unit and gives the limits defined for a taxonomic class. Areas of soils of principal hazards and limitations to be considered in a single taxonomic class rarely, if ever, can be planning for specific uses. mapped without including areas of other taxonomic Soils that have profiles that are almost alike make classes. Consequently, every map unit is made up of up a soil series. Except for differences in texture of the soils or miscellaneous areas for which it is named the surface layer, all of the soils of a series have and some minor components that belong to major horizons that are similar in composition, taxonomic classes other than those of the major thickness, and arrangement. soils. Soils of one series can differ in texture of the Most minor soils have properties similar to those of surface layer, slope, stoniness, salinity, degree of the dominant soil or soils in the map unit, and thus erosion, and other characteristics that affect their use. they do not affect use and management. These are On the basis of such differences, a soil series is 26 Soil Survey
divided into soil phases. Most of the areas shown on E1—0 to 7 inches; pale brown (10YR 6/3) gravelly the detailed soil maps are phases of soil series. The sandy loam, dark brown (10YR 4/3) moist; weak name of a soil phase commonly indicates a feature fine subangular blocky structure; soft, very friable, that affects use or management. For example, Bignell nonsticky, nonplastic; many very fine and fine and gravelly loam, 8 to 15 percent slopes, is one of common medium and coarse roots; many very several phases of the Bignell series. fine and common fine pores; 5 percent cobbles Some map units are made up of two or more major and 15 percent pebbles; moderately acid; clear soils or miscellaneous areas. These map units are wavy boundary. complexes, associations, or undifferentiated groups. E and Bt1—7 to 18 inches; E part (70 percent) is pale This survey includes complexes. They consist of brown (10YR 6/3) gravelly coarse sandy loam, two or more soils or miscellaneous areas in such an brown (10YR 5/3) moist; B part (30 percent) is 1/ intricate pattern or in such small areas that they brown (10YR 5/3) sandy loam lamellae, 4- to 3 cannot be shown separately on the maps. The /8-inch thick, dark brown (10YR 4/3) moist; pattern and proportion of the soils or miscellaneous moderate medium subangular blocky structure; areas are somewhat similar in all areas. Braziel- slightly hard, very friable, nonsticky, nonplastic; Tolbert complex, 8 to 15 percent slopes, is an many very fine and fine and common medium example. and coarse roots; many very fine and common This survey includes miscellaneous areas. They fine pores; 5 percent cobbles and 20 percent have little or no soil material and support little or no pebbles; moderately acid; clear wavy boundary. vegetation. Rubble land is an example. E and Bt2—18 to 32 inches; about 80 percent is pale The “Acreage and Proportionate Extent of the brown (10YR 6/3) gravelly coarse sandy loam, Soils” table in Parts I and II of the manuscript gives brown (10YR 5/3) moist (E part); about 20 the acreage and proportionate extent of each map percent is brown (10YR 5/3) gravelly sandy loam 1 3 unit. Other tables (see “Summary of Tables”) give lamellae, /4- to /8-inch thick, dark brown (10YR properties of the soils and the limitations, capabilities, 4/3) moist (B part); weak medium subangular and potentials for many uses. Many of the terms used blocky structure; slightly hard, very friable, in describing the soils or miscellaneous areas are nonsticky, nonplastic; common very fine and fine defined in the “Glossary.” and few medium and coarse roots; many very fine and common fine pores; 10 percent cobbles and 25 percent pebbles; slightly acid; clear wavy Ambrant Series boundary. 2C—32 to 60 inches; light yellowish brown (10YR Depth class: Very deep 6/4) very cobbly loamy coarse sand, dark Drainage class: Somewhat excessively drained yellowish brown (10YR 4/4) moist; massive; hard, Permeability: Moderately rapid to 2C, rapid below very friable, nonsticky, nonplastic; few very fine Landform: Mountains and fine roots; many very fine and common fine Parent material: Granitic colluvium pores; 5 percent stones, 15 percent cobbles, and Slope range: 4 to 60 percent 25 percent pebbles; moderately acid. Elevation range: 4,500 to 5,500 feet Annual precipitation: 18 to 25 inches Range in Characteristics Annual air temperature: 38 to 42 degrees F Frost-free period: 70 to 90 days Soil temperature: 42 to 47 degrees F Moisture control section: Between depths of 8 and Taxonomic Class: Coarse-loamy, mixed, 24 inches superactive, frigid Lamellic Haplustepts Depth to the 2C horizon: 28 to 46 inches Typical Pedon E1 horizon Value: 5 to 7 dry; 3 or 4 moist Ambrant gravelly sandy loam, in an area of Ambrant- Chroma: 2 or 3 Rochester complex, 35 to 60 percent slopes, in an Clay content: 5 to 15 percent area of woodland, 1,700 feet north and 1,600 feet Content of rock fragments: 15 to 35 percent—0 to east of the southwest corner of sec. 29, T. 11 N., 5 percent boulders, stones, and cobbles; 15 to R. 7 W. 30 percent angular pebbles Oe—1 inch to 0; partially decomposed forest litter. Reaction: pH 5.6 to 7.3 Powell County Area, Montana—Part I 27
E and Bt horizons Major Component Description Hue: E part—10YR or 2.5Y; B part—10YR or Ambrant 2.5Y Surface layer texture: Stony sandy loam Value: E part—6 or 7 dry, 4 to 6 moist; B part— Depth class: Very deep (more than 60 inches) 4 or 5 dry, 3 or 4 moist Drainage class: Somewhat excessively drained Chroma: E part—2 or 3; B part—2 or 3 Dominant parent material: Colluvium Clay content, mixed: 5 to 18 percent; lamellae Native plant cover type: Forestland have less than 3 percent clay increase Flooding: None Texture: Sandy loam or coarse sandy loam Available water capacity: Mainly 3.7 inches Content of rock fragments: 0 to 35 percent—0 to 10 percent cobbles; 10 to 35 percent angular Rochester pebbles Surface layer texture: Very stony sandy loam Reaction: pH 5.6 to 7.3 Depth class: Very deep (more than 60 inches) 2C horizon Drainage class: Excessively drained Hue: 10YR or 2.5Y Dominant parent material: Granitic colluvium Value: 5 to 7 dry; 4 or 5 moist Native plant cover type: Forestland Chroma: 1 to 4 Flooding: None Texture: Coarse sandy loam, coarse sand, loamy Available water capacity: Mainly 2.3 inches coarse sand, sand, or loamy sand Clay content: 0 to 5 percent A typical soil description with range in Content of rock fragments: 15 to 60 percent— characteristics is included, in alphabetical order, in 10 to 25 percent stones and cobbles; 10 to this section. 45 percent angular pebbles Management Reaction: pH 5.6 to 7.3 For management information about this map unit, see appropriate sections in Part II of this publication. 79D—Ambrant-Rochester complex, cool, 4 to 15 percent slopes 79E—Ambrant-Rochester complex, cool, 15 to 35 percent slopes Setting Setting Landform: • Ambrant—Mountains Landform: • Rochester—Mountains • Ambrant—Mountains Slope: • Rochester—Mountains • Ambrant—4 to 15 percent Slope: • Rochester—4 to 15 percent • Ambrant—15 to 35 percent Elevation: 4,500 to 5,500 feet • Rochester—15 to 35 percent Mean annual precipitation: 18 to 25 inches Elevation: 4,500 to 5,500 feet Frost-free period: 70 to 90 days Mean annual precipitation: 18 to 25 inches Frost-free period: 70 to 90 days Composition Composition Major Components Major Components Ambrant and similar soils: 50 percent Ambrant and similar soils: 50 percent Rochester and similar soils: 35 percent Rochester and similar soils: 35 percent Minor Components Minor Components Soils that have loamy sand or sand throughout: 0 to Soils that have loamy sand or sand throughout: 0 to 5 percent 5 percent Soils that have loam throughout: 0 to 5 percent Soils that have loam throughout: 0 to 5 percent Areas of rock outcrop: 0 to 5 percent Areas of rock outcrop: 0 to 5 percent 28 Soil Survey
Major Component Description Major Component Description Ambrant Ambrant Surface layer texture: Stony sandy loam Surface layer texture: Stony sandy loam Depth class: Very deep (more than 60 inches) Depth class: Very deep (more than 60 inches) Drainage class: Somewhat excessively drained Drainage class: Somewhat excessively drained Dominant parent material: Colluvium Dominant parent material: Colluvium Native plant cover type: Forestland Native plant cover type: Forestland Flooding: None Flooding: None Available water capacity: Mainly 3.7 inches Available water capacity: Mainly 3.7 inches
Rochester Rochester Surface layer texture: Very stony sandy loam Surface layer texture: Very stony sandy loam Depth class: Very deep (more than 60 inches) Depth class: Very deep (more than 60 inches) Drainage class: Excessively drained Drainage class: Excessively drained Dominant parent material: Granitic colluvium Dominant parent material: Granitic colluvium Native plant cover type: Forestland Native plant cover type: Forestland Flooding: None Flooding: None Available water capacity: Mainly 2.3 inches Available water capacity: Mainly 2.3 inches
A typical soil description with range in A typical soil description with range in characteristics is included, in alphabetical order, in characteristics is included, in alphabetical order, in this section. this section. Management Management For management information about this map unit, For management information about this map unit, see appropriate sections in Part II of this publication. see appropriate sections in Part II of this publication.
79F—Ambrant-Rochester complex, 179E—Ambrant-Rochester complex, cool, 35 to 60 percent slopes 15 to 35 percent slopes Setting Setting Landform: • Ambrant—Mountains Landform: • Rochester—Mountains • Ambrant—Mountains Slope: • Rochester—Mountains • Ambrant—35 to 60 percent Slope: • Rochester—35 to 60 percent • Ambrant—15 to 35 percent Elevation: 4,500 to 5,500 feet • Rochester—15 to 35 percent Mean annual precipitation: 18 to 25 inches Elevation: 4,500 to 5,500 feet Frost-free period: 70 to 90 days Mean annual precipitation: 18 to 25 inches Frost-free period: 70 to 90 days Composition Major Components Composition Ambrant and similar soils: 50 percent Rochester and similar soils: 35 percent Major Components Ambrant and similar soils: 50 percent Minor Components Rochester and similar soils: 35 percent Soils that have loamy sand or sand throughout: 0 to 5 percent Minor Components Soils that have loam throughout: 0 to 5 percent Soils that have a clayey subsoil: 0 to 10 percent Areas of rock outcrop: 0 to 5 percent Soils that are sandy below 10 inches: 0 to 5 percent Powell County Area, Montana—Part I 29
Major Component Description Major Component Description Ambrant Ambrant Surface layer texture: Stony sandy loam Surface layer texture: Stony sandy loam Depth class: Very deep (more than 60 inches) Depth class: Very deep (more than 60 inches) Drainage class: Somewhat excessively drained Drainage class: Somewhat excessively drained Dominant parent material: Colluvium Dominant parent material: Colluvium Native plant cover type: Forestland Native plant cover type: Forestland Flooding: None Flooding: None Available water capacity: Mainly 3.5 inches Available water capacity: Mainly 3.8 inches
Rochester Rochester Surface layer texture: Very stony sandy loam Surface layer texture: Very stony sandy loam Depth class: Very deep (more than 60 inches) Depth class: Very deep (more than 60 inches) Drainage class: Excessively drained Drainage class: Excessively drained Dominant parent material: Granitic colluvium Dominant parent material: Granitic colluvium Native plant cover type: Forestland Native plant cover type: Forestland Flooding: None Flooding: None Available water capacity: Mainly 2.3 inches Available water capacity: Mainly 2.3 inches
A typical soil description with range in A typical soil description with range in characteristics is included, in alphabetical order, in characteristics is included, in alphabetical order, in this section. this section. Management Management For management information about this map unit, For management information about this map unit, see appropriate sections in Part II of this publication. see appropriate sections in Part II of this publication.
179F—Ambrant-Rochester complex, 279E—Ambrant, cool-Rochester, 35 to 60 percent slopes cool-Rock outcrop complex, 15 to 35 percent slopes Setting Landform: Setting • Ambrant—Mountains Landform: • Rochester—Mountains • Ambrant—Mountains Slope: • Rochester—Mountains • Ambrant—35 to 60 percent • Rock outcrop—Mountains • Rochester—35 to 60 percent Slope: Elevation: 4,500 to 5,500 feet • Ambrant—15 to 35 percent Mean annual precipitation: 18 to 25 inches • Rochester—15 to 35 percent Frost-free period: 70 to 90 days Elevation: 4,500 to 5,500 feet Composition Mean annual precipitation: 18 to 25 inches Frost-free period: 70 to 90 days Major Components Ambrant and similar soils: 50 percent Composition Rochester and similar soils: 35 percent Major Components Minor Components Ambrant and similar soils: 35 percent Soils that have a clayey subsoil: 0 to 10 percent Rochester and similar soils: 30 percent Soils that are sandy below 10 inches: 0 to 5 percent Rock outcrop: 20 percent 30 Soil Survey
Minor Components Composition Soils that have bedrock at depths less than Major Components 60 inches: 0 to 5 percent Ambrant and similar soils: 35 percent Areas of rubble land: 0 to 5 percent Rochester and similar soils: 30 percent Soils that have slopes more than 35 percent: 0 to Rock outcrop: 20 percent 5 percent Minor Components Major Component Description Soils that have bedrock at depths of less than Ambrant 60 inches: 0 to 5 percent Surface layer texture: Bouldery coarse sandy loam Areas of rubble land: 0 to 5 percent Depth class: Very deep (more than 60 inches) Soils that have slopes more than 60 percent: 0 to Drainage class: Somewhat excessively drained 5 percent Dominant parent material: Colluvium Major Component Description Native plant cover type: Forestland Flooding: None Ambrant Available water capacity: Mainly 3.5 inches Surface layer texture: Bouldery coarse sandy loam Depth class: Very deep (more than 60 inches) Rochester Drainage class: Somewhat excessively drained Surface layer texture: Very bouldery coarse sandy Dominant parent material: Colluvium loam Native plant cover type: Forestland Depth class: Very deep (more than 60 inches) Flooding: None Drainage class: Excessively drained Available water capacity: Mainly 3.5 inches Dominant parent material: Granitic colluvium Native plant cover type: Forestland Rochester Flooding: None Surface layer texture: Very bouldery coarse sandy Available water capacity: Mainly 2.3 inches loam Depth class: Very deep (more than 60 inches) Rock outcrop Drainage class: Excessively drained Definition: Areas of exposed bedrock Dominant parent material: Granitic colluvium Native plant cover type: Forestland A typical soil description with range in Flooding: None characteristics is included, in alphabetical order, in Available water capacity: Mainly 2.3 inches this section. Rock outcrop Management Definition: Areas of exposed bedrock For management information about this map unit, see appropriate sections in Part II of this publication. A typical soil description with range in characteristics is included, in alphabetical order, in this section. 279F—Ambrant, cool-Rochester, cool-Rock outcrop complex, Management 35 to 60 percent slopes For management information about this map unit, see appropriate sections in Part II of this publication. Setting Landform: • Ambrant—Mountains 379E—Ambrant-Rochester-Rock outcrop • Rochester—Mountains complex, 15 to 35 percent slopes • Rock outcrop—Mountains Slope: Setting • Ambrant—35 to 60 percent • Rochester—35 to 60 percent Landform: Elevation: 4,500 to 5,500 feet • Ambrant—Mountains Mean annual precipitation: 18 to 25 inches • Rochester—Mountains Frost-free period: 70 to 90 days • Rock outcrop—Mountains Powell County Area, Montana—Part I 31
Slope: 379F—Ambrant-Rochester-Rock outcrop • Ambrant—15 to 35 percent complex, 35 to 60 percent slopes • Rochester—15 to 35 percent Elevation: 4,500 to 5,500 feet Setting Mean annual precipitation: 18 to 25 inches Frost-free period: 70 to 90 days Landform: • Ambrant—Mountains Composition • Rochester—Mountains Major Components • Rock outcrop—Mountains Ambrant and similar soils: 35 percent Slope: Rochester and similar soils: 30 percent • Ambrant—35 to 60 percent Rock outcrop: 20 percent • Rochester—35 to 60 percent Elevation: 4,500 to 5,500 feet Minor Components Mean annual precipitation: 18 to 25 inches Soils that have a clayey subsoil: 0 to 8 percent Frost-free period: 70 to 90 days Soils that are sandy below 10 inches: 0 to 7 percent Composition Major Component Description Major Components Ambrant and similar soils: 35 percent Ambrant Rochester and similar soils: 30 percent Surface layer texture: Bouldery coarse sandy loam Rock outcrop: 20 percent Depth class: Very deep (more than 60 inches) Drainage class: Somewhat excessively drained Minor Components Dominant parent material: Colluvium Soils that have a clayey subsoil: 0 to 8 percent Native plant cover type: Forestland Soils that are sandy below 10 inches: 0 to 7 percent Flooding: None Major Component Description Available water capacity: Mainly 3.5 inches Ambrant Rochester Surface layer texture: Bouldery coarse sandy loam Surface layer texture: Very bouldery coarse sandy Depth class: Very deep (more than 60 inches) loam Drainage class: Somewhat excessively drained Depth class: Very deep (more than 60 inches) Dominant parent material: Colluvium Drainage class: Excessively drained Native plant cover type: Forestland Dominant parent material: Granitic colluvium Flooding: None Native plant cover type: Forestland Available water capacity: Mainly 3.5 inches Flooding: None Available water capacity: Mainly 2.3 inches Rochester Surface layer texture: Very bouldery coarse sandy Rock outcrop loam Definition: Areas of exposed bedrock Depth class: Very deep (more than 60 inches) Drainage class: Excessively drained A typical soil description with range in Dominant parent material: Granitic colluvium characteristics is included, in alphabetical order, in Native plant cover type: Forestland this section. Flooding: None Available water capacity: Mainly 2.3 inches Management For management information about this map unit, Rock outcrop see appropriate sections in Part II of this publication. Definition: Areas of exposed bedrock 32 Soil Survey
A typical soil description with range in friable, nonsticky, nonplastic; few fine roots; many characteristics is included, in alphabetical order, in fine irregular pores; 10 percent pebbles; this section. continuous distinct lime coatings and casts on surface of pebbles; common fine masses of lime; Management strongly effervescent; moderately alkaline. For management information about this map unit, see appropriate sections in Part II of this publication. Range in Characteristics
Soil temperature: 41 to 46 degrees F Anaconda Series Moisture control section: Between depths of 4 and 12 inches; dry in all parts less than five-tenths Depth class: Very deep and dry in some part more than six-tenths Drainage class: Well drained of the cumulative days per year when the Permeability: Moderate soil temperature at a depth of 20 inches is Landform: Alluvial fans 41 degrees F or higher Parent material: Calcareous alluvium Thickness of the mollic epipedon: 7 to 9 inches Slope range: 0 to 60 percent Depth to the calcic horizon: 10 to 16 inches Elevation range: 4,000 to 5,000 feet Soil phases: Heavy metals Annual precipitation: 10 to 14 inches Annual air temperature: 39 to 44 degrees F Ap horizon Frost-free period: 90 to 105 days Chroma: 1 to 3 Clay content: 5 to 18 percent Taxonomic Class: Coarse-loamy, mixed, Content of rock fragments: 0 to 15 percent superactive, frigid Aridic Haplustolls pebbles Reaction: pH 5.6 to 7.3 (pH 5.6 to 6.5—heavy Typical Pedon metal phase) Anaconda loam, 0 to 4 percent slopes, in an area of Bw horizon cropland, 500 feet north and 600 feet west of the Value: 4 to 6 dry; 3 to 5 moist southeast corner of sec. 19, T. 7 N., R. 9 W. Chroma: 3 or 4 Ap—0 to 8 inches; brown (10YR 5/3) loam, dark Texture: Loam or sandy loam brown (10YR 3/3) moist; weak medium platy Clay content: 5 to 18 percent structure parting to moderate fine granular Content of rock fragments: 0 to 15 percent structure; loose, very friable, nonsticky, pebbles nonplastic; common fine and coarse roots; Reaction: pH 6.1 to 7.3 neutral; clear smooth boundary. Bk1 horizon Bw—8 to 14 inches; yellowish brown (10YR 5/4) Value: 7 or 8 dry; 5 to 7 moist loam, dark brown (10YR 4/3) moist; weak Chroma: 2 to 4 medium subangular blocky structure; soft, friable, Texture: Loam or sandy loam slightly sticky, slightly plastic; common fine Clay content: 5 to 18 percent and coarse roots; many fine irregular pores; Content of rock fragments: 0 to 20 percent—0 to 10 percent pebbles; neutral; clear wavy boundary. 5 percent cobbles; 0 to 15 percent pebbles Bk1—14 to 27 inches; white (10YR 8/2) gravelly Calcium carbonate equivalent: 15 to 40 percent loam, light yellowish brown (10YR 6/4) moist; Reaction: pH 7.9 to 8.4 weak fine subangular blocky structure; soft, friable, nonsticky, nonplastic; few fine roots; many Bk2 horizon fine irregular pores; 15 percent pebbles; Value: 5 to 8 dry; 4 or 6 moist continuous distinct lime coatings and casts on Chroma: 3 or 4 surface of pebbles; common fine masses of lime; Texture: Sandy loam or loam violently effervescent; moderately alkaline; clear Clay content: 5 to 18 percent wavy boundary. Content of rock fragments: 0 to 25 percent—0 to Bk2—27 to 60 inches; very pale brown (10YR 8/3) 5 percent cobbles; 0 to 20 percent pebbles sandy loam, light yellowish brown (10YR 6/4) Calcium carbonate equivalent: 15 to 25 percent moist; weak fine subangular blocky structure; soft, Reaction: pH 7.9 to 8.4 Powell County Area, Montana—Part I 33
35B—Anaconda loam, A—0 to 5 inches; dark gray (10YR 4/1) loam, very 0 to 4 percent slopes dark brown (10YR 2/2) moist; moderate fine and medium granular structure; soft, friable, slightly sticky, slightly plastic; strongly effervescent; Setting moderately alkaline; clear irregular boundary. Landform: Alluvial fans and stream terraces C1—5 to 16 inches; light brownish gray (5Y 6/2) Slope: 0 to 4 percent loam, dark grayish brown (5Y 4/2) moist; few fine Elevation: 4,000 to 5,000 feet prominent brownish yellow (10YR 6/8) redox Mean annual precipitation: 10 to 14 inches concentrations; moderate medium subangular Frost-free period: 90 to 105 days blocky structure; soft, friable, moderately sticky, slightly plastic; strongly effervescent; moderately Composition alkaline; gradual irregular boundary. C2—16 to 30 inches; light brownish gray (5Y 6/2) Major Components loam, dark grayish brown (5Y 4/2) moist; common Anaconda and similar soils: 85 percent fine and coarse prominent brownish yellow (10YR 6/8) redox concentrations; moderate very coarse Minor Components prismatic structure parting to weak coarse Anaconda very gravelly loam: 0 to 10 percent subangular blocky; soft, friable, slightly sticky, Somewhat poorly drained soils: 0 to 5 percent slightly plastic; moderately alkaline; clear wavy boundary. Major Component Description C3—30 to 60 inches; very pale brown (10YR 7/3) very gravelly coarse sand, light yellowish brown Surface layer texture: Loam (10YR 6/4) moist; single grain; loose, very friable, Depth class: Very deep (more than 60 inches) nonsticky, nonplastic; 45 percent pebbles; slightly Drainage class: Well drained alkaline. Dominant parent material: Alluvium Native plant cover type: Rangeland Range in Characteristics Flooding: None Clay content: 5 to 50 percent Available water capacity: Mainly 8.0 inches Rock fragments in the control section: 0 to 70 percent Depth to the seasonal high water table: 12 to A typical soil description with range in 24 inches characteristics is included, in alphabetical order, in this section. Management 4—Aquents-Slickens complex, 0 to 2 percent slopes, For management information about this map unit, occasionally flooded see appropriate sections in Part II of this publication. Setting Aquents Landform: • Aquents—Flood plains Depth class: Very deep • Slickens—Flood plains Drainage class: Poorly drained Slope: 0 to 2 percent Permeability: Moderate, moderately slow, or rapid Elevation: 3,600 to 5,200 feet Landform: Flood plains Mean annual precipitation: 10 to 14 inches Parent material: Alluvium Frost-free period: 90 to 105 days Slope range: 0 to 2 percent Composition Elevation range: 3,600 to 5,200 feet Annual precipitation: 10 to 14 inches Major Components Annual air temperature: 39 to 44 degrees F Aquents and similar soils: 55 percent Frost-free period: 90 to 105 days Slickens: 30 percent Minor Components Representative Pedon Very poorly drained soils: 0 to 7 percent Aquents, in an area of pasture, 1,100 feet north of the Areas of riverwash: 0 to 5 percent southeast corner of sec. 29, T. 9 N., R. 9 W. Areas of open water: 0 to 3 percent 34 Soil Survey
Major Component Description A2—4 to 10 inches; grayish brown (10YR 5/2) sandy loam, very dark grayish brown (10YR 3/2) moist; Aquents weak medium subangular blocky structure; soft, Surface layer texture: Loam very friable, nonsticky, nonplastic; many very fine Depth class: Very deep (more than 60 inches) and fine and few medium roots; many very fine Drainage class: Poorly drained and fine interstitial pores; neutral; clear smooth Dominant parent material: Alluvium boundary. Flooding: Occasional Bw—10 to 21 inches; light brownish gray (10YR 6/2) Water table: Apparent sandy loam, dark grayish brown (10YR 4/2) moist; weak coarse subangular blocky structure; Slickens soft, very friable, nonsticky, nonplastic; many very Definition: Material from ore mills, commonly freshly fine and fine roots; many very fine and fine ground rock that has undergone chemical interstitial pores; neutral; gradual wavy boundary. treatment during the milling process BC—21 to 43 inches; brown (7.5YR 5/4) sandy loam, Flooding: Occasional dark brown (7.5YR 4/4) moist; weak coarse subangular blocky; soft, very friable, nonsticky, A typical soil description with range in nonplastic; common fine roots; many very fine characteristics is included, in alphabetical order, in interstitial pores; 5 percent pebbles; moderately this section. alkaline; gradual wavy boundary. Management C—43 to 60 inches; brown (7.5YR 5/4) loamy sand, dark brown (7.5YR 4/4) moist; single-grained; For management information about this map unit, loose, nonsticky, nonplastic; few fine roots; see appropriate sections in Part II of this publication. common very fine interstitial pores; 10 percent pebbles; slightly alkaline. Baggs Series Range in Characteristics Depth class: Very deep Thickness of the mollic epipedon: 7 to 16 inches Drainage class: Well drained Permeability: Moderately rapid A horizons Landform: Alluvial fans Value: 4 or 5 dry; 2 or 3 moist Parent material: Alluvium Chroma: 1 to 3 Slope range: 0 to 15 percent Clay content: 5 to 18 percent Annual precipitation: 15 to 19 inches Reaction: pH 6.6 to 7.3 Annual air temperature: 39 to 44 degrees Bw horizon Frost-free period: 70 to 90 days Value: 5 or 6 dry; 3 to 5 moist Elevation range: 3,800 to 5,000 feet Chroma: 2 to 4 Clay content: 5 to 18 percent Taxonomic Class: Coarse-loamy, mixed, Content of rock fragments: 0 to 15 percent superactive, frigid Typic Haplustolls pebbles Typical Pedon Reaction: pH 6.6 to 7.3 Baggs sandy loam, cool, 0 to 4 percent slopes, in an BC horizon area of woodland, 4,800 feet north and 2,700 feet Hue: 10YR or 7.5YR east of the southwest corner of sec. 7, T. 15 N., Value: 5 to 7 dry; 4 or 5 moist R. 13 W. Chroma: 2 to 4 Texture: Fine sandy loam or sandy loam O—1.5 inches to 0; partially decomposed organic Clay content: 5 to 18 percent matter. Content of rock fragments: 0 to 15 percent A1—0 to 4 inches; dark grayish brown (10YR 4/2) pebbles sandy loam, very dark grayish brown (10YR 3/2) Reaction: pH 6.6 to 8.4 moist; moderate fine granular structure; soft, very friable, nonsticky, nonplastic; many very fine and C horizon fine and few medium roots; many very fine and Hue: 10YR or 7.5YR fine interstitial pores; neutral; clear smooth Value: 5 to 7 dry; 4 to 6 moist boundary. Chroma: 2 to 4 Powell County Area, Montana—Part I 35
Texture: Fine sandy loam, sandy loam, or loamy Mean annual precipitation: 15 to 19 inches sand Frost-free period: 70 to 90 days Clay content: 5 to 18 percent Composition Content of rock fragments: 0 to 15 percent pebbles Major Components Reaction: pH 6.6 to 7.9 Baggs and similar soils: 85 percent Minor Components Somewhat poorly drained soils: 0 to 4 percent 135B—Baggs sandy loam, Poorly drained soils: 0 to 4 percent 0 to 4 percent slopes Soils that are loamy below 10 inches: 0 to 4 percent Soils that have a loamy fine sand substratum: 0 to 3 percent Setting Major Component Description Landform: Alluvial fans Slope: 0 to 4 percent Surface layer texture: Sandy loam Elevation: 3,800 to 5,000 feet Depth class: Very deep (more than 60 inches) Mean annual precipitation: 15 to 19 inches Drainage class: Well drained Frost-free period: 70 to 90 days Dominant parent material: Alluvium Native plant cover type: Rangeland Composition Flooding: None Major Components Available water capacity: Mainly 7.6 inches Baggs and similar soils: 85 percent A typical soil description with range in Minor Components characteristics is included, in alphabetical order, in Soils that are somewhat poorly drained: 0 to this section. 8 percent Soils that have a loamy fine sand substratum: 0 to Management 7 percent For management information about this map unit, Major Component Description see appropriate sections in Part II of this publication. Surface layer texture: Sandy loam Depth class: Very deep (more than 60 inches) 135D—Baggs sandy loam, Drainage class: Well drained 8 to 15 percent slopes Dominant parent material: Alluvium Native plant cover type: Rangeland Setting Flooding: None Available water capacity: Mainly 7.6 inches Landform: Alluvial fans Slope: 8 to 15 percent A typical soil description with range in Elevation: 3,800 to 5,000 feet characteristics is included, in alphabetical order, in Mean annual precipitation: 15 to 19 inches this section. Frost-free period: 70 to 90 days Management Composition For management information about this map unit, Major Components see appropriate sections in Part II of this publication. Baggs and similar soils: 85 percent Minor Components 135C—Baggs sandy loam, Soils that have a loamy fine sand substratum: 0 to 4 to 8 percent slopes 15 percent Major Component Description Setting Surface layer texture: Sandy loam Landform: Alluvial fans Depth class: Very deep (more than 60 inches) Slope: 4 to 8 percent Drainage class: Well drained Elevation: 3,800 to 5,000 feet Dominant parent material: Alluvium 36 Soil Survey
Native plant cover type: Rangeland Permeability: Moderate to the 2Bk1 horizon, rapid Flooding: None below Available water capacity: Mainly 7.6 inches Landform: Alluvial fans and stream terraces Parent material: Alluvium A typical soil description with range in Slope range: 0 to 8 percent characteristics is included, in alphabetical order, in Elevation range: 3,600 to 5,200 feet this section. Annual precipitation: 10 to 14 inches Annual air temperature: 39 to 44 degrees F Management Frost-free period: 90 to 105 days For management information about this map unit, see appropriate sections in Part II of this publication. Taxonomic Class: Loamy-skeletal over sandy or sandy-skeletal, mixed, superactive, frigid Aridic Argiustolls 479B—Baggs sandy loam, cool, 0 to 4 percent slopes Typical Pedon
Setting Beaverell cobbly loam, 0 to 4 percent slopes, in an area of rangeland, 2,000 feet south and 1,200 feet Landform: Alluvial fans east of the northwest corner of sec. 10, T. 7 N., Slope: 0 to 4 percent R. 10 W. Elevation: 3,800 to 5,000 feet Mean annual precipitation: 15 to 19 inches A—0 to 5 inches; grayish brown (10YR 5/2) cobbly Frost-free period: 70 to 90 days loam, very dark brown (10YR 2/2) moist; weak medium platy structure parting to moderate Composition medium granular structure; soft, friable, nonsticky, Major Components nonplastic; many very fine and fine roots; Baggs and similar soils: 85 percent common very fine discontinuous vesicular pores; 10 percent cobbles and 15 percent pebbles; Minor Components slightly acid; clear wavy boundary. Quigley soils: 0 to 4 percent Bt1—5 to 12 inches; brown (7.5YR 5/4) very gravelly Soils that are sandy below 10 inches: 0 to 4 percent loam, brown (7.5YR 4/4) moist; weak medium Somewhat poorly drained soils: 0 to 4 percent prismatic structure parting to moderate medium Soils that have a dark surface: 0 to 3 percent subangular blocky structure; slightly hard, firm, Major Component Description slightly sticky, slightly plastic; common very fine and fine roots; few very fine discontinuous pores; Surface layer texture: Sandy loam few faint clay films on faces of peds; 15 percent Depth class: Very deep (more than 60 inches) cobbles and 35 percent pebbles; neutral; gradual Drainage class: Well drained wavy boundary. Dominant parent material: Alluvium Bt2—12 to 16 inches; yellowish brown (10YR 5/6) Native plant cover type: Forestland very gravelly loam, dark yellowish brown (10YR Flooding: None 4/6) moist; moderate medium subangular blocky Available water capacity: Mainly 6.2 inches structure; slightly hard, firm, slightly sticky, slightly plastic; common very fine and fine roots; few very A typical soil description with range in fine discontinuous pores; common faint clay characteristics is included, in alphabetical order, in films on faces of peds; 15 percent cobbles and this section. 35 percent pebbles; neutral; clear wavy boundary. Management 2Bk1—16 to 31 inches; white (10YR 8/2) extremely gravelly loamy sand, light brownish gray (10YR For management information about this map unit, 6/2) moist; weak very fine subangular blocky see appropriate sections in Part II of this publication. structure; soft, very friable, nonsticky, nonplastic; few fine roots; 20 percent cobbles and 40 percent Beaverell Series pebbles; disseminated lime; continuous distinct lime casts surrounding coarse fragments; Depth class: Very deep violently effervescent; slightly alkaline; gradual Drainage class: Well drained wavy boundary. Powell County Area, Montana—Part I 37
2Bk2—31 to 60 inches; reddish yellow (5YR 6/6) Content of rock fragments: 35 to 75 percent—5 to extremely gravelly loamy sand, yellowish red 30 percent cobbles; 30 to 45 percent pebbles (5YR 5/6) moist; single grain; loose, nonsticky, Calcium carbonate equivalent: 5 to 15 percent nonplastic; 20 percent cobbles and 45 percent Reaction: pH 7.4 to 8.4 pebbles; disseminated lime; continuous distinct 2Bk2 horizon lime casts surrounding coarse fragments; Hue: 5YR, 10YR, or 2.5Y strongly effervescent; slightly alkaline. Value: 4 to 6 dry; 4 to 6 moist Chroma: 2 to 4 or 6 Range in Characteristics Texture: Loamy sand or sand Clay content: 0 to 5 percent Soil temperature: 40 to 47 degrees F Content of rock fragments: 35 to 80 percent—5 to Moisture control section: Between depths of 4 and 30 percent stones and cobbles; 30 to 60 12 inches; dry in all parts less than five-tenths percent pebbles and dry in some part more than six-tenths of Calcium carbonate equivalent: 2 to 10 percent the cumulative days per year when the soil Reaction: pH 7.4 to 8.4 temperature at 20 inches is 41 degrees F or higher Thickness of the mollic epipedon: 7 to 14 inches Depth to the Bk horizon: 10 to 20 inches 132B—Beaverell cobbly loam, 0 to 4 percent slopes A horizon Value: 2 or 3 moist Chroma: 2 or 3 Setting Clay content: 10 to 27 percent Landform: Alluvial fans and stream terraces Content of rock fragments: 5 to 35 percent—0 to Slope: 0 to 4 percent 15 percent cobbles; 5 to 20 percent pebbles Elevation: 3,600 to 5,200 feet Reaction: pH 6.6 to 7.8 Mean annual precipitation: 10 to 14 inches Bt1 horizon Frost-free period: 90 to 105 days Hue: 10YR or 7.5YR Composition Value: 3 to 5 dry; 2 to 4 moist Chroma: 2 to 4 Major Components Texture: Clay loam, sandy clay loam, or loam Beaverell and similar soils: 85 percent Clay content: 20 to 35 percent Minor Components Content of rock fragments: 35 to 60 percent—0 to Somewhat poorly drained soils: 0 to 15 percent 15 percent cobbles; 35 to 45 percent pebbles Reaction: pH 6.6 to 7.8 Major Component Description Bt2 horizon Surface layer texture: Cobbly loam Hue: 7.5YR, 10YR, or 2.5Y Depth class: Very deep (more than 60 inches) Value: 3 to 5 dry; 2 to 4 moist Drainage class: Well drained Chroma: 2 to 4 or 6 Dominant parent material: Alluvium Texture: Clay loam, sandy clay loam, or loam Native plant cover type: Rangeland Clay content: 20 to 35 percent Flooding: None Content of rock fragments: 35 to 60 percent—0 to Available water capacity: Mainly 2.9 inches 15 percent cobbles; 35 to 45 percent pebbles Reaction: pH 6.6 to 7.8 A typical soil description with range in 2Bk1 horizon characteristics is included, in alphabetical order, in Hue: 10YR or 2.5Y this section. Value: 5 to 8 dry; 4 to 6 moist Management Chroma: 2 to 4 Texture: Loamy sand or sand For management information about this map unit, Clay content: 0 to 5 percent see appropriate sections in Part II of this publication. 38 Soil Survey
132C—Beaverell cobbly loam, Soils that have a cobbly loam surface: 0 to 3 percent 4 to 8 percent slopes Soils that have slopes more than 4 percent: 0 to 3 percent Major Component Description Setting Surface layer texture: Loam Landform: Alluvial fans and stream terraces Depth class: Very deep (more than 60 inches) Slope: 4 to 8 percent Drainage class: Well drained Elevation: 3,600 to 5,200 feet Dominant parent material: Alluvium Mean annual precipitation: 10 to 14 inches Native plant cover type: Rangeland Frost-free period: 90 to 105 days Flooding: None Composition Available water capacity: Mainly 3.7 inches Major Components A typical soil description with range in Beaverell and similar soils: 85 percent characteristics is included, in alphabetical order, in Minor Components this section. Anaconda soils: 0 to 15 percent Management Major Component Description For management information about this map unit, Surface layer texture: Cobbly loam see appropriate sections in Part II of this publication. Depth class: Very deep (more than 60 inches) Drainage class: Well drained Dominant parent material: Alluvium Bignell Series Native plant cover type: Rangeland Flooding: None Depth class: Very deep Available water capacity: Mainly 2.9 inches Drainage class: Well drained Permeability: Slow A typical soil description with range in Landform: Mountains, moraines, and hills characteristics is included, in alphabetical order, in Parent material: Colluvium derived from fine-grained this section. extrusive igneous rocks and till Slope range: 8 to 60 percent Management Elevation range: 4,000 to 6,500 feet For management information about this map unit, Annual precipitation: 18 to 30 inches see appropriate sections in Part II of this publication. Annual air temperature: 38 to 42 degrees F Frost-free period: 70 to 90 days
332B—Beaverell loam, Taxonomic Class: Clayey-skeletal, mixed, 0 to 4 percent slopes superactive, frigid Typic Haplustalfs
Setting Typical Pedon Landform: Alluvial fans and stream terraces Bignell gravelly clay loam, cool, 15 to 35 percent Slope: 0 to 4 percent slopes, in an area of woodland, 2,100 feet south and Elevation: 3,600 to 5,200 feet 1,400 feet west of the northeast corner of sec. 24, Mean annual precipitation: 10 to 14 inches T. 10 N., R. 9 W. Frost-free period: 90 to 105 days Oi—2 inches to 0; undecomposed and slightly Composition decomposed forest litter. E—0 to 13 inches; light brownish gray (10YR 6/2) Major Components gravelly clay loam, brown (10YR 4/3) moist; weak Beaverell and similar soils: 85 percent fine subangular blocky structure; slightly hard, Minor Components friable, nonsticky, slightly plastic; many very fine Very gravelly sandy soils: 0 to 5 percent and fine and common medium roots; common Somewhat poorly drained soils: 0 to 4 percent very fine and fine pores; 5 percent cobbles and Powell County Area, Montana—Part I 39
20 percent pebbles; moderately acid; clear wavy Texture: Loam, sandy clay loam, or clay loam boundary. Content of rock fragments: 25 to 60 percent—0 to E/Bt—13 to 17 inches; about 75 percent pinkish gray 25 percent cobbles; 15 to 55 percent pebbles (7.5YR 6/2) very gravelly clay loam, brown Reaction: pH 5.1 to 6.5 (7.5YR 5/2) moist (E part); 25 percent brown Bt horizons (7.5YR 5/4) very gravelly clay loam, dark brown Hue: 5YR, 7.5YR, or 10YR (7.5YR 4/4) moist (B part); common distinct clay Value: 5 to 7 dry; 3 to 6 moist films on faces of peds; moderate medium Chroma: 2 to 4 or 6 subangular blocky structure parting to weak fine Texture: Clay, sandy clay, or clay loam subangular blocky structure; slightly hard, firm, Clay content: 35 to 60 percent slightly sticky, moderately plastic; many very fine Content of rock fragments: 35 to 60 percent—0 to and fine and common medium roots; common 30 percent cobbles; 15 to 45 percent pebbles very fine and fine pores; 5 percent cobbles and Reaction: pH 5.1 to 6.5 40 percent pebbles; slightly acid; clear wavy boundary. Bt1—17 to 25 inches; brown (7.5YR 5/4) very gravelly clay, dark brown (7.5YR 4/4) moist; moderate 99D—Bignell gravelly clay loam, medium subangular blocky structure; very hard, 8 to 15 percent slopes firm, moderately sticky, moderately plastic; common very fine and few fine roots; few very Setting fine and fine pores; common distinct clay films on faces of peds; 15 percent cobbles and 40 percent Landform: Hills pebbles; slightly acid; clear wavy boundary. Slope: 8 to 15 percent Bt2—25 to 60 inches; brown (7.5YR 5/4) very gravelly Elevation: 4,000 to 6,500 feet clay loam, dark brown (7.5YR 4/4) moist; strong Mean annual precipitation: 18 to 26 inches fine subangular blocky structure; very hard, firm, Frost-free period: 70 to 90 days moderately sticky, moderately plastic; few very Composition fine and fine roots; few very fine and fine pores; common distinct clay films on faces of peds; Major Components 15 percent cobbles and 45 percent pebbles; Bignell and similar soils: 85 percent moderately acid. Minor Components Range in Characteristics Crow soils: 0 to 5 percent Yreka soils: 0 to 4 percent Soil temperature: 42 to 46 degrees F Areas of rock outcrop: 0 to 3 percent Moisture control section: Between depths of 4 and Soils that are shallow: 0 to 3 percent 12 inches E horizon Major Component Description Hue: 7.5YR or 10YR Surface layer texture: Gravelly clay loam Value: 6 or 7 dry; 4 to 6 moist Depth class: Very deep (more than 60 inches) Chroma: 2 to 4 Drainage class: Well drained Texture: Loam or clay loam Dominant parent material: Colluvium Clay content: 10 to 35 percent Native plant cover type: Forestland Content of rock fragments: 15 to 35 percent—0 to Flooding: None 10 percent stones and cobbles; 15 to 25 Available water capacity: Mainly 5.3 inches percent pebbles Reaction: pH 5.1 to 6.0 A typical soil description with range in E/Bt horizon characteristics is included, in alphabetical order, in Hue: E part—7.5YR or 10YR; B part—7.5YR or this section. 10YR Management Value: E part—6 or 7 dry, 5 or 6 moist; B part— 5 to 7 dry For management information about this map unit, Chroma: E part—2 or 3; B part—2, 4, or 6 see appropriate sections in Part II of this publication. 40 Soil Survey
99E—Bignell gravelly clay loam, Minor Components 15 to 35 percent slopes Crow soils: 0 to 5 percent Yreka soils: 0 to 4 percent Areas of rock outcrop: 0 to 3 percent Setting Soils that are shallow: 0 to 3 percent Landform: Hills Major Component Description Slope: 15 to 35 percent Elevation: 4,000 to 6,500 feet Surface layer texture: Gravelly clay loam Mean annual precipitation: 18 to 26 inches Depth class: Very deep (more than 60 inches) Frost-free period: 70 to 90 days Drainage class: Well drained Dominant parent material: Colluvium Composition Native plant cover type: Forestland Major Components Flooding: None Bignell and similar soils: 85 percent Available water capacity: Mainly 5.3 inches Minor Components A typical soil description with range in Crow soils: 0 to 4 percent characteristics is included, in alphabetical order, in Yreka soils: 0 to 4 percent this section. Areas of rock outcrop: 0 to 3 percent Soils that are shallow: 0 to 3 percent Management Major Component Description For management information about this map unit, see appropriate sections in Part II of this publication. Surface layer texture: Gravelly clay loam Depth class: Very deep (more than 60 inches) Drainage class: Well drained Dominant parent material: Colluvium 199E—Bignell gravelly clay loam, Native plant cover type: Forestland cool, 15 to 35 percent slopes Flooding: None Available water capacity: Mainly 5.3 inches Setting A typical soil description with range in Landform: Hills characteristics is included, in alphabetical order, in Slope: 15 to 35 percent this section. Elevation: 4,000 to 6,500 feet Mean annual precipitation: 18 to 26 inches Management Frost-free period: 70 to 90 days For management information about this map unit, Composition see appropriate sections in Part II of this publication. Major Components Bignell and similar soils: 85 percent 99F—Bignell gravelly clay loam, 35 to 60 percent slopes Minor Components Yreka soils: 0 to 5 percent Areas of rock outcrop: 0 to 5 percent Setting Soils that are gravelly loam throughout: 0 to 5 percent Landform: Hills Major Component Description Slope: 35 to 60 percent Elevation: 4,000 to 6,500 feet Surface layer texture: Gravelly clay loam Mean annual precipitation: 18 to 26 inches Depth class: Very deep (more than 60 inches) Frost-free period: 70 to 90 days Drainage class: Well drained Dominant parent material: Colluvium Composition Native plant cover type: Forestland Major Components Flooding: None Bignell and similar soils: 85 percent Available water capacity: Mainly 5.3 inches Powell County Area, Montana—Part I 41
A typical soil description with range in Slope: characteristics is included, in alphabetical order, in • Bignell—15 to 35 percent this section. • Yreka—15 to 35 percent Elevation: 4,000 to 6,500 feet Management Mean annual precipitation: 18 to 26 inches For management information about this map unit, Frost-free period: 70 to 90 days see appropriate sections in Part II of this publication. Composition Major Components 199F—Bignell gravelly clay loam, Bignell and similar soils: 50 percent cool, 35 to 60 percent slopes Yreka and similar soils: 35 percent Minor Components Setting Areas of rock outcrop: 0 to 4 percent Trapps soils: 0 to 4 percent Landform: Hills Soils that have slopes more than 35 percent: 0 to Slope: 35 to 60 percent 4 percent Elevation: 4,000 to 6,500 feet Poorly drained soils: 0 to 3 percent Mean annual precipitation: 18 to 26 inches Frost-free period: 70 to 90 days Major Component Description Composition Bignell Surface layer texture: Gravelly clay loam Major Components Depth class: Very deep (more than 60 inches) Bignell and similar soils: 85 percent Drainage class: Well drained Minor Components Dominant parent material: Colluvium Yreka soils: 0 to 10 percent Native plant cover type: Forestland Areas of rock outcrop: 0 to 5 percent Flooding: None Available water capacity: Mainly 5.3 inches Major Component Description Surface layer texture: Gravelly clay loam Yreka Depth class: Very deep (more than 60 inches) Surface layer texture: Gravelly loam Drainage class: Well drained Depth class: Very deep (more than 60 inches) Dominant parent material: Colluvium Drainage class: Well drained Native plant cover type: Forestland Dominant parent material: Colluvium Flooding: None Native plant cover type: Forestland Available water capacity: Mainly 5.3 inches Flooding: None Available water capacity: Mainly 5.6 inches A typical soil description with range in characteristics is included, in alphabetical order, in A typical soil description with range in this section. characteristics is included, in alphabetical order, in this section. Management Management For management information about this map unit, see appropriate sections in Part II of this publication. For management information about this map unit, see appropriate sections in Part II of this publication.
299E—Bignell-Yreka complex, 299F—Bignell-Yreka complex, 15 to 35 percent slopes 35 to 60 percent slopes
Setting Setting Landform: Landform: • Bignell—Hills • Bignell—Hills • Yreka—Hills • Yreka—Hills 42 Soil Survey
Slope: Slope: • Bignell—35 to 60 percent • Bignell—15 to 35 percent • Yreka—35 to 60 percent • Yreka—15 to 35 percent Elevation: 4,000 to 6,500 feet Elevation: 4,000 to 6,500 feet Mean annual precipitation: 18 to 26 inches Mean annual precipitation: 18 to 26 inches Frost-free period: 70 to 90 days Frost-free period: 70 to 90 days Composition Composition Major Components Major Components Bignell and similar soils: 50 percent Bignell and similar soils: 50 percent Yreka and similar soils: 35 percent Yreka and similar soils: 35 percent Minor Components Minor Components Areas of rock outcrop: 0 to 4 percent Areas of rock outcrop: 0 to 4 percent Trapps soils: 0 to 4 percent Soils that are moderately deep: 0 to 4 percent Soils that have slopes more than 35 percent: 0 to Poorly drained soils: 0 to 4 percent 4 percent Soils that have a gravelly clay subsoil: 0 to 3 percent Poorly drained soils: 0 to 3 percent Major Component Description Major Component Description Bignell Bignell Surface layer texture: Gravelly clay loam Surface layer texture: Gravelly clay loam Depth class: Very deep (more than 60 inches) Depth class: Very deep (more than 60 inches) Drainage class: Well drained Drainage class: Well drained Dominant parent material: Colluvium Dominant parent material: Colluvium Native plant cover type: Forestland Native plant cover type: Forestland Flooding: None Flooding: None Available water capacity: Mainly 5.3 inches Available water capacity: Mainly 5.3 inches Yreka Yreka Surface layer texture: Gravelly loam Surface layer texture: Gravelly loam Depth class: Very deep (more than 60 inches) Depth class: Very deep (more than 60 inches) Drainage class: Well drained Drainage class: Well drained Dominant parent material: Colluvium Dominant parent material: Colluvium Native plant cover type: Forestland Native plant cover type: Forestland Flooding: None Flooding: None Available water capacity: Mainly 5.6 inches Available water capacity: Mainly 5.6 inches A typical soil description with range in A typical soil description with range in characteristics is included, in alphabetical order, in characteristics is included, in alphabetical order, in this section. this section. Management Management For management information about this map unit, For management information about this map unit, see appropriate sections in Part II of this publication. see appropriate sections in Part II of this publication.
399E—Bignell-Yreka complex, cool, 399F—Bignell-Yreka complex, cool, 15 to 35 percent slopes 35 to 60 percent slopes
Setting Setting Landform: Landform: • Bignell—Hills • Bignell—Hills • Yreka—Hills • Yreka—Hills Powell County Area, Montana—Part I 43
Slope: Slope: • Bignell—35 to 60 percent • Bignell—8 to 15 percent • Yreka—35 to 60 percent • Yreka—8 to 15 percent Elevation: 4,000 to 6,500 feet Elevation: 4,000 to 6,500 feet Mean annual precipitation: 18 to 26 inches Mean annual precipitation: 18 to 26 inches Frost-free period: 70 to 90 days Frost-free period: 70 to 90 days Composition Composition Major Components Major Components Bignell and similar soils: 50 percent Bignell and similar soils: 50 percent Yreka and similar soils: 35 percent Yreka and similar soils: 35 percent Minor Components Minor Components Areas of rock outcrop: 0 to 4 percent Soils that are less than 60-inches deep: 0 to Soils that are moderately deep: 0 to 4 percent 5 percent Poorly drained soils: 0 to 4 percent Areas of rock outcrop: 0 to 5 percent Soils that have a gravelly clay subsoil: 0 to 3 percent Crow soils: 0 to 5 percent Major Component Description Major Component Description Bignell Bignell Surface layer texture: Gravelly clay loam Surface layer texture: Gravelly clay loam Depth class: Very deep (more than 60 inches) Depth class: Very deep (more than 60 inches) Drainage class: Well drained Drainage class: Well drained Dominant parent material: Colluvium Dominant parent material: Colluvium Native plant cover type: Forestland Native plant cover type: Forestland Flooding: None Flooding: None Available water capacity: Mainly 5.3 inches Available water capacity: Mainly 5.3 inches
Yreka Yreka Surface layer texture: Gravelly loam Surface layer texture: Gravelly loam Depth class: Very deep (more than 60 inches) Depth class: Very deep (more than 60 inches) Drainage class: Well drained Drainage class: Well drained Dominant parent material: Colluvium Dominant parent material: Colluvium Native plant cover type: Forestland Native plant cover type: Forestland Flooding: None Flooding: None Available water capacity: Mainly 5.6 inches Available water capacity: Mainly 5.6 inches
A typical soil description with range in A typical soil description with range in characteristics is included, in alphabetical order, in characteristics is included, in alphabetical order, in this section. this section. Management Management For management information about this map unit, For management information about this map unit, see appropriate sections in Part II of this publication. see appropriate sections in Part II of this publication.
499D—Bignell, cool-Yreka complex, 499E—Bignell, cool-Yreka complex, 8 to 15 percent slopes 15 to 35 percent slopes
Setting Setting Landform: Landform: • Bignell—Hills • Bignell—Hills • Yreka—Hills • Yreka—Hills 44 Soil Survey
Slope: Slope: • Bignell—15 to 35 percent • Bignell—35 to 60 percent • Yreka—15 to 35 percent • Yreka—35 to 60 percent Elevation: 4,000 to 6,500 feet Elevation: 4,000 to 6,500 feet Mean annual precipitation: 18 to 26 inches Mean annual precipitation: 18 to 26 inches Frost-free period: 70 to 90 days Frost-free period: 70 to 90 days Composition Composition Major Components Major Components Bignell and similar soils: 50 percent Bignell and similar soils: 50 percent Yreka and similar soils: 35 percent Yreka and similar soils: 35 percent Minor Components Minor Components Soils that are less than 60-inches deep: 0 to Soils that are less than 60-inches deep: 0 to 5 percent 5 percent Areas of rock outcrop: 0 to 5 percent Areas of rock outcrop: 0 to 5 percent Crow soils: 0 to 5 percent Crow soils: 0 to 5 percent Major Component Description Major Component Description Bignell Bignell Surface layer texture: Gravelly clay loam Surface layer texture: Gravelly clay loam Depth class: Very deep (more than 60 inches) Depth class: Very deep (more than 60 inches) Drainage class: Well drained Drainage class: Well drained Dominant parent material: Colluvium Dominant parent material: Colluvium Native plant cover type: Forestland Native plant cover type: Forestland Flooding: None Flooding: None Available water capacity: Mainly 5.3 inches Available water capacity: Mainly 5.3 inches
Yreka Yreka Surface layer texture: Gravelly loam Surface layer texture: Gravelly loam Depth class: Very deep (more than 60 inches) Depth class: Very deep (more than 60 inches) Drainage class: Well drained Drainage class: Well drained Dominant parent material: Colluvium Dominant parent material: Colluvium Native plant cover type: Forestland Native plant cover type: Forestland Flooding: None Flooding: None Available water capacity: Mainly 5.6 inches Available water capacity: Mainly 5.6 inches
A typical soil description with range in A typical soil description with range in characteristics is included, in alphabetical order, in characteristics is included, in alphabetical order, in this section. this section. Management Management For management information about this map unit, For management information about this map unit, see appropriate sections in Part II of this publication. see appropriate sections in Part II of this publication.
499F—Bignell, cool-Yreka complex, 699D—Bignell gravelly loam, 35 to 60 percent slopes 8 to 15 percent slopes
Setting Setting Landform: Landform: Hills • Bignell—Hills Slope: 8 to 15 percent • Yreka—Hills Elevation: 4,000 to 6,500 feet Powell County Area, Montana—Part I 45
Mean annual precipitation: 18 to 26 inches Major Component Description Frost-free period: 70 to 90 days Surface layer texture: Gravelly loam Composition Depth class: Very deep (more than 60 inches) Drainage class: Well drained Major Components Dominant parent material: Colluvium Bignell and similar soils: 85 percent Native plant cover type: Forestland Minor Components Flooding: None Crow soils: 0 to 4 percent Available water capacity: Mainly 5.2 inches Yreka soils: 0 to 3 percent Winkler soils: 0 to 3 percent A typical soil description with range in Areas of rock outcrop: 0 to 3 percent characteristics is included, in alphabetical order, in Soils that are shallow: 0 to 2 percent this section. Major Component Description Management Surface layer texture: Gravelly loam For management information about this map unit, Depth class: Very deep (more than 60 inches) see appropriate sections in Part II of this publication. Drainage class: Well drained Dominant parent material: Colluvium Native plant cover type: Forestland 699F—Bignell gravelly loam, Flooding: None 35 to 60 percent slopes Available water capacity: Mainly 5.2 inches Setting A typical soil description with range in Landform: Hills characteristics is included, in alphabetical order, in Slope: 35 to 60 percent this section. Elevation: 4,000 to 6,500 feet Management Mean annual precipitation: 18 to 26 inches Frost-free period: 70 to 90 days For management information about this map unit, see appropriate sections in Part II of this publication. Composition Major Components 699E—Bignell gravelly loam, Bignell and similar soils: 85 percent 15 to 35 percent slopes Minor Components Crow soils: 0 to 4 percent Setting Yreka soils: 0 to 3 percent Winkler soils: 0 to 3 percent Landform: Hills Areas of rock outcrop: 0 to 3 percent Slope: 15 to 35 percent Soils that are shallow: 0 to 2 percent Elevation: 4,000 to 6,500 feet Mean annual precipitation: 18 to 26 inches Major Component Description Frost-free period: 70 to 90 days Surface layer texture: Gravelly loam Composition Depth class: Very deep (more than 60 inches) Drainage class: Well drained Major Components Dominant parent material: Colluvium Bignell and similar soils: 85 percent Native plant cover type: Forestland Minor Components Flooding: None Crow soils: 0 to 4 percent Available water capacity: Mainly 5.2 inches Yreka soils: 0 to 3 percent Winkler soils: 0 to 3 percent A typical soil description with range in Areas of rock outcrop: 0 to 3 percent characteristics is included, in alphabetical order, in Soils that are shallow: 0 to 2 percent this section. 46 Soil Survey
Management Crow Surface layer texture: Loam For management information about this map unit, Depth class: Very deep (more than 60 inches) see appropriate sections in Part II of this publication. Drainage class: Well drained Dominant parent material: Colluvium Native plant cover type: Forestland 799D—Bignell-Yreka-Crow complex, Flooding: None 8 to 15 percent slopes Available water capacity: Mainly 9.0 inches
Setting A typical soil description with range in characteristics is included, in alphabetical order, in Landform: this section. • Bignell—Hills • Yreka—Hills Management • Crow—Hills For management information about this map unit, Slope: see appropriate sections in Part II of this publication. • Bignell—8 to 15 percent • Yreka—8 to 15 percent • Crow—8 to 15 percent 799E—Bignell-Yreka-Crow complex, Elevation: 4,000 to 5,800 feet 15 to 35 percent slopes Mean annual precipitation: 18 to 24 inches Frost-free period: 70 to 90 days Setting Composition Landform: Major Components • Bignell—Hills Bignell and similar soils: 55 percent • Yreka—Hills Yreka and similar soils: 15 percent • Crow—Hills Crow and similar soils: 15 percent Slope: • Bignell—15 to 35 percent Minor Components • Yreka—15 to 35 percent Areas of rock outcrop: 0 to 5 percent • Crow—15 to 35 percent Soils that are shallow to bedrock: 0 to 5 percent Elevation: 4,000 to 5,800 feet Soils that have slopes more than 15 percent: 0 to Mean annual precipitation: 18 to 24 inches 5 percent Frost-free period: 70 to 90 days Major Component Description Composition Bignell Major Components Surface layer texture: Gravelly loam Bignell and similar soils: 55 percent Depth class: Very deep (more than 60 inches) Yreka and similar soils: 15 percent Drainage class: Well drained Crow and similar soils: 15 percent Dominant parent material: Colluvium Native plant cover type: Forestland Minor Components Flooding: None Areas of rock outcrop: 0 to 5 percent Available water capacity: Mainly 5.2 inches Soils that are shallow to bedrock: 0 to 5 percent Soils that have slopes more than 15 percent: 0 to Yreka 5 percent Surface layer texture: Gravelly loam Major Component Description Depth class: Very deep (more than 60 inches) Drainage class: Well drained Bignell Dominant parent material: Colluvium Surface layer texture: Gravelly loam Native plant cover type: Forestland Depth class: Very deep (more than 60 inches) Flooding: None Drainage class: Well drained Available water capacity: Mainly 5.6 inches Dominant parent material: Colluvium Powell County Area, Montana—Part I 47
Native plant cover type: Forestland Winfall soils: 0 to 5 percent Flooding: None Soils that have slopes more than 15 percent: 0 to Available water capacity: Mainly 5.2 inches 5 percent
Yreka Major Component Description Surface layer texture: Gravelly loam Bignell Depth class: Very deep (more than 60 inches) Surface layer texture: Gravelly clay loam Drainage class: Well drained Depth class: Very deep (more than 60 inches) Dominant parent material: Colluvium Drainage class: Well drained Native plant cover type: Forestland Dominant parent material: Colluvium Flooding: None Native plant cover type: Forestland Available water capacity: Mainly 5.6 inches Flooding: None Available water capacity: Mainly 5.3 inches Crow Surface layer texture: Loam Rumblecreek Depth class: Very deep (more than 60 inches) Surface layer texture: Gravelly loam Drainage class: Well drained Depth class: Very deep (more than 60 inches) Dominant parent material: Colluvium Drainage class: Well drained Native plant cover type: Forestland Dominant parent material: Colluvium Flooding: None Native plant cover type: Forestland Available water capacity: Mainly 9.0 inches Flooding: None Available water capacity: Mainly 5.2 inches A typical soil description with range in characteristics is included, in alphabetical order, in A typical soil description with range in this section. characteristics is included, in alphabetical order, in Management this section. For management information about this map unit, Management see appropriate sections in Part II of this publication. For management information about this map unit, see appropriate sections in Part II of this publication. 999D—Bignell-Rumblecreek complex, 8 to 15 percent slopes 999E—Bignell-Rumblecreek complex, Setting 15 to 35 percent slopes Landform: • Bignell—Hills Setting • Rumblecreek—Hills Landform: Slope: • Bignell—Hills • Bignell—8 to 15 percent • Rumblecreek—Hills • Rumblecreek—8 to 15 percent Slope: Elevation: 4,000 to 6,500 feet • Bignell—15 to 35 percent Mean annual precipitation: 18 to 26 inches • Rumblecreek—15 to 35 percent Frost-free period: 70 to 90 days Elevation: 4,000 to 6,500 feet Composition Mean annual precipitation: 18 to 26 inches Frost-free period: 70 to 90 days Major Components Bignell and similar soils: 50 percent Composition Rumblecreek and similar soils: 35 percent Major Components Minor Components Bignell and similar soils: 50 percent Crow soils: 0 to 5 percent Rumblecreek and similar soils: 35 percent 48 Soil Survey
Minor Components Minor Components Crow soils: 0 to 5 percent Crow soils: 0 to 5 percent Winfall soils: 0 to 5 percent Winfall soils: 0 to 5 percent Soils that have slopes more than 35 percent: 0 to Soils that have slopes more than 60 percent: 0 to 5 percent 5 percent Major Component Description Major Component Description Bignell Bignell Surface layer texture: Gravelly clay loam Surface layer texture: Gravelly clay loam Depth class: Very deep (more than 60 inches) Depth class: Very deep (more than 60 inches) Drainage class: Well drained Drainage class: Well drained Dominant parent material: Colluvium Dominant parent material: Colluvium Native plant cover type: Forestland Native plant cover type: Forestland Flooding: None Flooding: None Available water capacity: Mainly 5.3 inches Available water capacity: Mainly 5.3 inches Rumblecreek Rumblecreek Surface layer texture: Gravelly loam Surface layer texture: Gravelly loam Depth class: Very deep (more than 60 inches) Depth class: Very deep (more than 60 inches) Drainage class: Well drained Drainage class: Well drained Dominant parent material: Colluvium Dominant parent material: Colluvium Native plant cover type: Forestland Native plant cover type: Forestland Flooding: None Flooding: None Available water capacity: Mainly 5.2 inches Available water capacity: Mainly 5.2 inches A typical soil description with range in A typical soil description with range in characteristics is included, in alphabetical order, in characteristics is included, in alphabetical order, in this section. this section. Management Management For management information about this map unit, For management information about this map unit, see appropriate sections in Part II of this publication. see appropriate sections in Part II of this publication. Blossberg Series
999F—Bignell-Rumblecreek complex, Depth class: Very deep 35 to 60 percent slopes Drainage class: Poorly drained Permeability: Moderately slow to the 2C, rapid below Landform: Flood plains and low stream terraces Setting Parent material: Alluvium Landform: Slope range: 0 to 4 percent • Bignell—Hills Elevation range: 3,800 to 6,000 feet • Rumblecreek—Hills Annual precipitation: 10 to 19 inches Slope: Annual air temperature: 39 to 44 degrees F • Bignell—35 to 60 percent Frost-free period: 70 to 105 days • Rumblecreek—35 to 60 percent Elevation: 4,000 to 6,500 feet Taxonomic Class: Fine-loamy over sandy or sandy- Mean annual precipitation: 18 to 26 inches skeletal, mixed, superactive, frigid Typic Frost-free period: 70 to 90 days Endoaquolls Composition Typical Pedon Major Components Blossberg loam, 0 to 4 percent slopes, in an area of Bignell and similar soils: 50 percent pasture, 2,400 feet south and 200 feet west of the Rumblecreek and similar soils: 35 percent northeast corner of sec. 6, T. 6 N., R. 9 W. Powell County Area, Montana—Part I 49
A—0 to 14 inches; black (10YR 2/1) loam, very dark Bg1 horizon gray (10YR 3/1) dry; many large prominent Hue: 5Y, 2.5Y, or 10YR yellowish brown (10YR 5/6) redox concentrations; Value: 3 or 4 moist; 5 or 6 dry moderate fine granular structure; slightly hard, Chroma: 2 or 3 very friable, slightly sticky, slightly plastic; many Redox concentrations: 10YR 4/4 or 10YR 4/6 very fine, fine, medium, and coarse roots; many moist; 10YR 5/6 or 10YR 5/8 dry very fine and fine irregular pores; neutral; clear Texture: Clay loam, loam, or silty clay loam smooth boundary. Clay content: 18 to 35 percent Bg1—14 to 23 inches; dark grayish brown (2.5Y 4/2) Content of rock fragments: 0 to 15 percent—0 to loam, grayish brown (2.5Y 5/2) dry; many large 5 percent cobbles; 0 to 10 percent pebbles prominent yellowish brown (10YR 5/8) redox Reaction: pH 7.4 to 8.4 concentrations; moderate medium subangular Bg2 horizon blocky structure; slightly hard, very friable, slightly Hue: 5Y, 2.5Y, or 10YR sticky, moderately plastic; many very fine roots; Value: 4 or 5 moist; 5 or 6 dry many very fine and fine irregular pores; 5 percent Chroma: 1 or 2 cobbles; slightly alkaline; gradual smooth Redox concentrations: 2.5YR 4/6 or 2.5YR 4/8 boundary. moist; 2.5YR 5/6 or 2.5YR 5/8 dry Bg2—23 to 28 inches; grayish brown (2.5Y 5/2) Texture: Loam or sandy loam gravelly loam, light brownish gray (2.5Y 6/2) dry; Clay content: 10 to 20 percent few fine prominent red (2.5YR 5/8) redox Content of rock fragments: 20 to 40 percent—5 to concentrations; moderate medium subangular 15 percent cobbles; 15 to 25 percent pebbles blocky structure; slightly hard, very friable, slightly Reaction: pH 7.4 to 8.4 sticky, moderately plastic; many very fine and fine roots; many very fine and fine irregular pores; 2Cg horizon 5 percent cobbles and 20 percent pebbles; Value: 4 or 5 moist; 6 or 7 dry slightly alkaline; gradual wavy boundary. Chroma: 2 or 3 2Cg—28 to 60 inches; dark grayish brown (10YR 4/2) Redox concentrations: 2.5YR 4/6 or 2.5YR 4/8 very cobbly loamy coarse sand, light brownish moist; 2.5YR 5/6 or 2.5YR 5/8 dry gray (10YR 6/2) dry; common large prominent Texture: Coarse sand, loamy coarse sand, or red (2.5YR 5/8) redox concentrations; single sand grain; loose, nonsticky, nonplastic; many very fine Clay content: 0 to 10 percent and fine roots; many very fine and fine irregular Content of rock fragments: 35 to 60 percent— pores; 35 percent cobbles and 20 percent 25 to 35 percent cobbles; 10 to 25 percent pebbles; slightly alkaline. pebbles Reaction: pH 7.4 to 8.4 Range in Characteristics Soil temperature: 41 to 47 degrees F Moisture control section: Between depths of 4 to 634—Blossberg loam, 12 inches 0 to 4 percent slopes Depth to the seasonal high water table: 12 to 24 inches Depth to the 2Cg horizon: 20 to 40 inches Setting Thickness of the mollic epipedon: 10 to 24 inches Landform: Stream terraces A horizon Slope: 0 to 4 percent Value: 2 or 3 moist; 3 to 5 dry Elevation: 3,800 to 5,200 feet Redox concentrations: 10YR 4/4 or 10YR 4/6 Mean annual precipitation: 10 to 14 inches moist; 10YR 5/6 or 10YR 5/8 dry Frost-free period: 90 to 105 days Clay content: 18 to 27 percent clay Composition Content of rock fragments: 0 to 15 percent—0 to 5 percent cobbles; 0 to 10 percent pebbles Major Components Reaction: pH 6.6 to 7.8 Blossberg and similar soils: 85 percent 50 Soil Survey
Minor Components Water table: Apparent Very poorly drained soils: 0 to 5 percent Available water capacity: Mainly 5.0 inches Bushong soils: 0 to 5 percent Tetonview soils: 0 to 5 percent A typical soil description with range in characteristics is included, in alphabetical order, in Major Component Description this section. Surface layer texture: Loam Management Depth class: Very deep (more than 60 inches) Drainage class: Poorly drained For management information about this map unit, Dominant parent material: Alluvium see appropriate sections in Part II of this publication. Native plant cover type: Rangeland Flooding: None Water table: Apparent Bohnly Series Available water capacity: Mainly 5.0 inches Depth class: Very deep Drainage class: Poorly drained A typical soil description with range in Permeability: Moderate characteristics is included, in alphabetical order, in Landform: Low stream terraces this section. Parent material: Alluvium Management Slope range: 0 to 2 percent Elevation range: 3,600 to 4,800 feet For management information about this map unit, Annual precipitation: 15 to 19 inches see appropriate sections in Part II of this publication. Annual air temperature: 39 to 44 degrees F Frost-free period: 70 to 90 days 834—Blossberg loam, 0 to 4 percent slopes, rarely flooded Taxonomic Class: Fine-silty, mixed, superactive, frigid Typic Endoaquolls Setting Typical Pedon Landform: Flood plains Bohnly silt loam, 0 to 2 percent slopes, in an area of Slope: 0 to 4 percent pasture, 1,320 feet north and 2,200 feet east of the Elevation: 3,800 to 5,200 feet southwest corner of sec. 3, T. 7 N., R. 9 W. Mean annual precipitation: 10 to 14 inches Oe—4 to 0 inches; partially decomposed peat. Frost-free period: 90 to 105 days A—0 to 12 inches; very dark gray (10YR 3/1) silt Composition loam, dark gray (10YR 4/1) dry; moderate fine granular structure; soft, friable, moderately sticky, Major Components slightly plastic; many fine and medium roots; Blossberg and similar soils: 85 percent many irregular pores; 5 percent pebbles; Minor Components moderately alkaline; gradual wavy boundary. Dougcliff soils: 0 to 3 percent Bw—12 to 18 inches; dark gray (10YR 4/1) silt loam, Soils that are very gravelly below 8 inches: 0 to gray (10YR 5/1) dry; few fine faint yellowish 3 percent brown (10YR 5/6) redox concentrations; weak Turrah soils: 0 to 3 percent fine subangular blocky structure parting to Very poorly drained soils: 0 to 3 percent moderate medium granular structure; slightly Gregson soils: 0 to 3 percent hard, friable, moderately sticky, slightly plastic; many fine and medium roots; common irregular Major Component Description pores; 5 percent pebbles; moderately alkaline; Surface layer texture: Loam gradual wavy boundary. Depth class: Very deep (more than 60 inches) Cg1—18 to 27 inches; dark grayish brown (2.5Y 4/2) Drainage class: Poorly drained silt loam, light brownish gray (2.5Y 6/2) dry; few Dominant parent material: Alluvium fine prominent yellowish brown (10YR 5/6) redox Native plant cover type: Rangeland concentrations; moderate medium subangular Flooding: Rare blocky structure; slightly hard, friable, slightly Powell County Area, Montana—Part I 51
sticky, slightly plastic; common fine and medium Clay content: 18 to 32 percent roots; common irregular pores; 5 percent pebbles; Reaction: pH 6.6 to 7.8 moderately alkaline; gradual wavy boundary. Cg3 and Cg4 horizons Cg2—27 to 32 inches; dark grayish brown (2.5Y 4/2) Hue: 10YR, 2.5Y, or 5Y silt loam, grayish brown (2.5Y 5/2) dry; common Value: 4 to 6 moist; 6 or 7 dry fine prominent yellowish brown (10YR 5/6) redox Redox features: 7.5YR 5/6, 7.5YR 4/6, 10YR 5/6, concentrations; moderate medium subangular 10YR 5/1, or 10YR 4/1 blocky structure; hard, firm, moderately sticky, Clay content: 18 to 32 percent moderately plastic; few very fine and fine roots; Content of rock fragments: 0 to 15 percent—0 to common irregular pores; 5 percent pebbles; 5 percent cobbles; 0 to 10 percent pebbles moderately alkaline; gradual wavy boundary. Reaction: pH 6.6 to 7.8 Cg3—32 to 41 inches; gray (5Y 5/1) silty clay loam, gray (5Y 6/1) dry; common fine prominent yellowish brown (10YR 5/6) redox concentrations; 109—Bohnly silt loam, weak coarse prismatic structure; hard, firm, 0 to 2 percent slopes moderately sticky, moderately plastic; few very fine and fine roots; common irregular pores; Setting 5 percent pebbles; moderately alkaline; clear smooth boundary. Landform: Stream terraces Cg4—41 to 60 inches; gray (5Y 5/1) silty clay loam, Slope: 0 to 2 percent gray (5Y 6/1) dry; common fine prominent Elevation: 3,600 to 4,800 feet yellowish brown (10YR 5/6) redox concentrations; Mean annual precipitation: 15 to 19 inches weak coarse prismatic structure; hard, firm, Frost-free period: 70 to 90 days moderately sticky, moderately plastic; few fine Composition roots; common irregular pores; moderately alkaline. Major Components Bohnly and similar soils: 85 percent Range in Characteristics Minor Components Dougcliff soils: 0 to 8 percent Soil temperature: 41 to 47 degrees F Poronto soils: 0 to 7 percent Moisture control section: Between depths of 4 and 12 inches Major Component Description Thickness of the mollic epipedon: 7 to 12 inches Surface layer texture: Silt loam Depth to the seasonal high water table: 6 to 24 inches Depth class: Very deep (more than 60 inches) Drainage class: Poorly drained A horizon Dominant parent material: Alluvium Value: 2 or 3 moist; 3 to 5 dry Native plant cover type: Rangeland Chroma: 1 or 2 Flooding: None Clay content: 18 to 27 percent Water table: Apparent Reaction: pH 6.6 to 7.8 Available water capacity: Mainly 11.4 inches Bw horizon Hue: 10YR or 2.5Y A typical soil description with range in Value: 2 to 5 moist; 3 to 6 dry characteristics is included, in alphabetical order, in Chroma: 1 or 2 this section. Clay content: 18 to 27 percent Management Reaction: pH 6.6 to 7.8 For management information about this map unit, Cg1 and Cg2 horizons see appropriate sections in Part II of this publication. Hue: 10YR, 2.5Y, or 5Y Value: 2 to 4 moist; 5 to 7 dry Chroma: 1 or 2 Boxwell Series Redox features: 7.5YR 5/6, 7.5YR 4/6, 10YR 5/6, 10YR 5/1, or 10YR 4/1 Depth class: Moderately deep Texture: Silt loam or silty clay loam Drainage class: Well drained 52 Soil Survey
Permeability: Moderate Range in Characteristics Landform: Sedimentary plains and hills Soil temperature: 41 to 47 degrees F Parent material: Material derived from Moisture control section: Between depths of 4 and semiconsolidated sedimentary beds 12 inches; dry in all parts less than five-tenths Slope range: 0 to 35 percent and dry in some part more than six-tenths Elevation range: 4,000 to 5,200 feet of the cumulative days per year when the Annual precipitation: 10 to 14 inches soil temperature at a depth of 20 inches is Annual air temperature: 39 to 44 degrees F 41 degrees F or higher Frost-free period: 90 to 105 days Depth to the Bk horizon: 8 to 16 inches Depth to the Cr horizon: 20 to 40 inches Taxonomic Class: Fine-loamy, mixed, superactive, frigid Aridic Haplustolls A horizon Hue: 10YR or 2.5Y Typical Pedon Chroma: 2 or 3 Boxwell loam, in an area of Dolus-Boxwell complex, Clay content: 15 to 27 percent 15 to 35 percent slopes, in an area of rangeland, Reaction: pH 6.1 to 7.3 2,100 feet north and 2,150 feet west of the southeast Bw horizon corner of sec. 28, T. 9 N., R. 9 W. Hue: 10YR or 2.5Y A—0 to 3 inches; brown (10YR 5/3) loam, dark brown Value: 4 to 6 dry; 3 to 5 moist (10YR 3/3) moist; moderate medium granular Chroma: 2 to 4 structure; soft, very friable, nonsticky, nonplastic; Texture: Silt loam, clay loam, loam, or silty clay many very fine and fine and common medium loam roots; many fine irregular pores; 5 percent Clay content: 18 to 35 percent sandstone channers; neutral; clear smooth Content of rock fragments: 0 to 15 percent boundary. pebbles or channers Bw—3 to 11 inches; brown (10YR 5/3) loam, dark Reaction: pH 6.6 to 7.8 brown (10YR 3/3) moist; moderate medium Bk horizons subangular blocky structure parting to moderate Hue: 10YR, 2.5Y, or 5Y medium granular structure; slightly hard, friable, Value: 6 to 8 dry; 4, 5 to 7 moist nonsticky, nonplastic; common very fine and fine Chroma: 2 or 3 and few medium roots; common fine irregular and Texture: Clay loam, silty clay loam, silty loam, tubular pores; 5 percent sandstone channers; loam, or very fine sandy loam neutral; clear wavy boundary. Clay content: 15 to 30 percent Bk1—11 to 25 inches; very pale brown (10YR 7/3) Content of rock fragments: 0 to 15 percent clay loam, pale brown (10YR 6/3) moist; weak pebbles or channers fine subangular blocky structure; slightly hard, Calcium carbonate equivalent: 15 to 30 percent friable, moderately sticky, moderately plastic; few Reaction: pH 7.4 to 8.4 fine roots; common very fine and fine tubular pores; 5 percent sandstone channers; few fine Cr horizon soft masses of lime; violently effervescent; Semiconsolidated sedimentary beds moderately alkaline; gradual smooth boundary. Bk2—25 to 36 inches; pale brown (10YR 6/3) silty clay loam, brown (10YR 4/3) moist; weak fine 69C—Boxwell loam, 4 to 8 percent slopes subangular blocky structure; slightly hard, friable, moderately sticky, moderately plastic; few fine Setting roots; many fine tubular pores; 10 percent sandstone channers; few fine soft masses of lime; Landform: Sedimentary plains violently effervescent; moderately alkaline; Slope: 4 to 8 percent gradual smooth boundary. Elevation: 4,000 to 5,200 feet Cr—36 to 60 inches; semiconsolidated sedimentary Mean annual precipitation: 10 to 14 inches beds. Frost-free period: 90 to 105 days Powell County Area, Montana—Part I 53
Composition A typical soil description with range in characteristics is included, in alphabetical order, in Major Components this section. Boxwell and similar soils: 85 percent Management Minor Components Soils that have a clayey subsoil: 0 to 10 percent For management information about this map unit, Areas of rock outcrop: 0 to 5 percent see appropriate sections in Part II of this publication. Major Component Description Surface layer texture: Loam 69E—Boxwell loam, Depth class: Moderately deep (20 to 40 inches) 15 to 35 percent slopes Drainage class: Well drained Dominant parent material: Semiconsolidated Setting sedimentary beds Landform: Hills Native plant cover type: Rangeland Slope: 15 to 35 percent Flooding: None Elevation: 4,000 to 5,200 feet Available water capacity: Mainly 6.2 inches Mean annual precipitation: 10 to 14 inches Frost-free period: 90 to 105 days A typical soil description with range in characteristics is included, in alphabetical order, in Composition this section. Major Components Management Boxwell and similar soils: 85 percent For management information about this map unit, Minor Components see appropriate sections in Part II of this publication. Soils that are shallow to sandstone: 0 to 15 percent Major Component Description 69D—Boxwell loam, Surface layer texture: Loam 8 to 15 percent slopes Depth class: Moderately deep (20 to 40 inches) Drainage class: Well drained Dominant parent material: Semiconsolidated Setting sedimentary beds Landform: Hills Native plant cover type: Rangeland Slope: 8 to 15 percent Flooding: None Elevation: 4,000 to 5,200 feet Available water capacity: Mainly 6.2 inches Mean annual precipitation: 10 to 14 inches Frost-free period: 90 to 105 days A typical soil description with range in characteristics is included, in alphabetical order, in Composition this section. Major Components Management Boxwell and similar soils: 85 percent For management information about this map unit, Minor Components see appropriate sections in Part II of this publication. Soils that have a clayey subsoil: 0 to 10 percent Areas of rock outcrop: 0 to 5 percent Major Component Description Braziel Series Surface layer texture: Loam Depth class: Very deep Depth class: Moderately deep (20 to 40 inches) Drainage class: Well drained Drainage class: Well drained Permeability: Moderately slow Dominant parent material: Semiconsolidated Landform: Mountains and moraines sedimentary beds Parent material: Alpine till and material derived from Native plant cover type: Rangeland fine-grained extrusive igneous rock Flooding: None Slope range: 4 to 60 percent Available water capacity: Mainly 6.2 inches Elevation range: 3,800 to 5,000 feet 54 Soil Survey
Annual precipitation: 15 to 19 inches Range in Characteristics Annual air temperature: 39 to 44 degrees F Soil temperature: 41 to 46 degrees F Frost-free period: 70 to 90 days Moisture control section: Between depths of 4 and 12 inches Taxonomic Class: Loamy-skeletal, mixed, Thickness of the mollic epipedon: 16 to 30 inches superactive, frigid Pachic Argiustolls A1 horizon Typical Pedon Value: 3 to 5 dry; 2 or 3 moist Chroma: 2 or 3 dry; 1 to 3 moist Braziel gravelly loam, 15 to 35 percent slopes, in an Clay content: 18 to 27 percent area of pasture, 1,200 feet south and 1,450 feet east Content of rock fragments: 15 to 35 percent—0 to of the northwest corner of sec. 21, T. 7 N., R. 10 W. 10 percent stones and cobbles; 15 to A1—0 to 5 inches; grayish brown (10YR 5/2) gravelly 25 percent pebbles loam, very dark grayish brown (10YR 3/3) moist; Reaction: pH 6.6 to 7.3 strong fine granular structure; soft, friable, slightly A2 horizon sticky, slightly plastic; many very fine and fine and Value: 3 to 5 dry; 2 or 3 moist few medium roots; many very fine and fine pores; Chroma: 2 or 3 dry; 1 to 3 moist 10 percent cobbles and 20 percent pebbles; Clay content: 18 to 27 percent neutral; clear smooth boundary. Content of rock fragments: 5 to 60 percent—0 to A2—5 to 8 inches; brown (10YR 5/3) gravelly clay 15 percent stones; 0 to 10 percent cobbles; loam, dark brown (10YR 3/3) moist; moderate 5 to 25 percent pebbles medium granular structure; slightly hard, friable, Reaction: pH 6.6 to 7.3 slightly sticky, moderately plastic; many very fine and fine and few medium roots; many very Bt1 horizon fine and fine pores; 10 percent cobbles and Value: 4 or 5 dry; 3 moist 20 percent pebbles; neutral; clear smooth Chroma: 2 or 3 dry; 2 or 3 moist boundary. Texture: Sandy clay loam, clay loam, or loam Bt1—8 to 29 inches; brown (10YR 5/3) very gravelly Clay content: 25 to 35 percent clay loam, dark brown (10YR 3/3) moist; Content of rock fragments: 35 to 60 percent—0 to moderate fine subangular blocky structure; 5 percent stones; 5 to 15 percent cobbles; slightly hard, friable, slightly sticky, slightly plastic; 30 to 45 percent pebbles many very fine and fine and few medium roots; Reaction: pH 6.6 to 7.3 many very fine and fine pores; few faint clay Bt2 horizon films on faces of peds; 15 percent cobbles and Value: 4 to 6 dry; 3 or 4 moist 35 percent pebbles; neutral; gradual smooth Chroma: 3 or 4 dry; 2 to 4 moist boundary. Texture: Clay loam, sandy clay loam, or loam Bt2—29 to 43 inches; light yellowish brown (10YR Clay content: 25 to 35 percent 6/4) very gravelly clay loam, dark yellowish brown Content of rock fragments: 35 to 75 percent—0 to (10YR 4/4) moist; weak fine subangular blocky 10 percent stones; 5 to 20 percent cobbles; structure; slightly hard, friable, slightly sticky, 30 to 40 percent pebbles moderately plastic; common very fine and fine Reaction: pH 6.6 to 7.3 roots; many very fine and fine pores; common faint clay films on faces of peds; 15 percent BC horizon cobbles and 35 percent pebbles; neutral; clear Value: 5 to 7 dry; 3 to 6 moist smooth boundary. Chroma: 3 or 4 dry; 2 to 4 moist BC—43 to 60 inches; very pale brown (10YR 7/3) Texture: Sandy loam, sandy clay loam, loam, or very gravelly loam, pale brown (10YR 6/3) moist; clay loam massive; slightly hard, friable, slightly sticky, Clay content: 15 to 30 percent slightly plastic; common very fine and fine roots; Content of rock fragments: 35 to 70 percent—0 to 10 percent cobbles and 40 percent pebbles; 15 percent stones; 5 to 35 percent cobbles; neutral. 25 to 40 percent pebbles Powell County Area, Montana—Part I 55
Effervescence: None to slightly A typical soil description with range in Reaction: pH 6.6 to 7.8 characteristics is included, in alphabetical order, in this section. Management 200E—Braziel-Tolbert-Rock outcrop complex, 15 to 35 percent slopes For management information about this map unit, see appropriate sections in Part II of this publication.
Setting 200F—Braziel-Tolbert-Rock outcrop Landform: complex, 35 to 60 percent slopes • Braziel—Mountains • Tolbert—Mountains Setting • Rock outcrop—Mountains Slope: Landform: • Braziel—15 to 35 percent • Braziel—Mountains • Tolbert—15 to 35 percent • Tolbert—Mountains Elevation: 3,800 to 5,000 feet • Rock outcrop—Mountains Mean annual precipitation: 15 to 19 inches Slope: Frost-free period: 70 to 90 days • Braziel—35 to 60 percent • Tolbert—35 to 50 percent Composition Elevation: 3,800 to 5,000 feet Major Components Mean annual precipitation: 15 to 19 inches Braziel and similar soils: 40 percent Frost-free period: 70 to 90 days Tolbert and similar soils: 30 percent Composition Rock outcrop: 15 percent Major Components Minor Components Braziel and similar soils: 40 percent Soils that are moderately deep: 0 to 8 percent Tolbert and similar soils: 30 percent Soils that have slopes more than 35 percent: 0 to Rock outcrop: 15 percent 7 percent Minor Components Major Component Description Soils that are moderately deep: 0 to 7 percent Braziel Soils that have slopes more than 60 percent: 0 to Surface layer texture: Stony loam 8 percent Depth class: Very deep (more than 60 inches) Major Component Description Drainage class: Well drained Dominant parent material: Material weathered from Braziel igneous rocks Surface layer texture: Stony loam Native plant cover type: Rangeland Depth class: Very deep (more than 60 inches) Flooding: None Drainage class: Well drained Available water capacity: Mainly 5.3 inches Dominant parent material: Material weathered from igneous rocks Tolbert Native plant cover type: Rangeland Surface layer texture: Very stony loam Flooding: None Depth class: Shallow (10 to 20 inches) Available water capacity: Mainly 5.3 inches Drainage class: Well drained Dominant parent material: Igneous residuum Tolbert Native plant cover type: Rangeland Surface layer texture: Very stony loam Flooding: None Depth class: Shallow (10 to 20 inches) Available water capacity: Mainly 1.7 inches Drainage class: Well drained Dominant parent material: Igneous residuum Rock outcrop Native plant cover type: Rangeland Definition: Areas of exposed bedrock Flooding: None Available water capacity: Mainly 0.0 inches Available water capacity: Mainly 1.7 inches 56 Soil Survey
Rock outcrop A typical soil description with range in Definition: Areas of exposed bedrock characteristics is included, in alphabetical order, in this section. A typical soil description with range in Management characteristics is included, in alphabetical order, in this section. For management information about this map unit, see appropriate sections in Part II of this publication. Management For management information about this map unit, see appropriate sections in Part II of this publication. 242D—Braziel gravelly loam, 8 to 15 percent slopes 242C—Braziel-Perma gravelly loams, 4 to 8 percent slopes Setting Landform: Mountains Setting Slope: 8 to 15 percent Elevation: 3,800 to 5,000 feet Landform: Mean annual precipitation: 15 to 19 inches • Braziel—Mountains Frost-free period: 70 to 90 days • Perma—Mountains Slope: Composition • Braziel—4 to 8 percent Major Components • Perma—4 to 8 percent Braziel and similar soils: 85 percent Elevation: 3,800 to 5,000 feet Mean annual precipitation: 15 to 19 inches Minor Components Frost-free period: 70 to 90 days Soils that are moderately deep: 0 to 8 percent Shawmut soils: 0 to 7 percent Composition Major Component Description Major Components Braziel and similar soils: 45 percent Surface layer texture: Gravelly loam Perma and similar soils: 40 percent Depth class: Very deep (more than 60 inches) Drainage class: Well drained Minor Components Dominant parent material: Material weathered from Soils that are moderately deep: 0 to 8 percent igneous rocks Shawmut soils: 0 to 7 percent Native plant cover type: Rangeland Major Component Description Flooding: None Available water capacity: Mainly 5.3 inches Braziel Surface layer texture: Gravelly loam A typical soil description with range in Depth class: Very deep (more than 60 inches) characteristics is included, in alphabetical order, in Drainage class: Well drained this section. Dominant parent material: Material weathered from igneous rocks Management Native plant cover type: Rangeland For management information about this map unit, Flooding: None see appropriate sections in Part II of this publication. Available water capacity: Mainly 5.3 inches
Perma 242E—Braziel gravelly loam, Surface layer texture: Gravelly loam 15 to 35 percent slopes Depth class: Very deep (more than 60 inches) Drainage class: Somewhat excessively drained Setting Dominant parent material: Alluvium Native plant cover type: Rangeland Landform: Mountains Flooding: None Slope: 15 to 35 percent Available water capacity: Mainly 4.2 inches Elevation: 3,800 to 5,000 feet Powell County Area, Montana—Part I 57
Mean annual precipitation: 15 to 19 inches Dominant parent material: Material weathered from Frost-free period: 70 to 90 days igneous rocks Native plant cover type: Rangeland Composition Flooding: None Major Components Available water capacity: Mainly 5.2 inches Braziel and similar soils: 85 percent A typical soil description with range in Minor Components characteristics is included, in alphabetical order, in Soils that are moderately deep: 0 to 8 percent this section. Shawmut soils: 0 to 7 percent Management Major Component Description For management information about this map unit, Surface layer texture: Gravelly loam see appropriate sections in Part II of this publication. Depth class: Very deep (more than 60 inches) Drainage class: Well drained Dominant parent material: Material weathered from igneous rocks 342E—Braziel stony loam, Native plant cover type: Rangeland 15 to 35 percent slopes Flooding: None Available water capacity: Mainly 5.3 inches Setting A typical soil description with range in Landform: Mountains characteristics is included, in alphabetical order, in Slope: 15 to 35 percent this section. Elevation: 3,800 to 5,000 feet Mean annual precipitation: 15 to 19 inches Management Frost-free period: 70 to 90 days For management information about this map unit, Composition see appropriate sections in Part II of this publication. Major Components Braziel and similar soils: 85 percent 342D—Braziel stony loam, 8 to 15 percent slopes Minor Components Areas of rock outcrop: 0 to 5 percent Soils that are moderately deep: 0 to 5 percent Setting Roy soils: 0 to 5 percent Landform: Mountains Slope: 8 to 15 percent Major Component Description Elevation: 3,800 to 5,000 feet Surface layer texture: Stony loam Mean annual precipitation: 15 to 19 inches Depth class: Very deep (more than 60 inches) Frost-free period: 70 to 90 days Drainage class: Well drained Composition Dominant parent material: Material weathered from igneous rocks Major Components Native plant cover type: Rangeland Braziel and similar soils: 85 percent Flooding: None Minor Components Available water capacity: Mainly 5.2 inches Areas of rock outcrop: 0 to 5 percent Soils that are moderately deep: 0 to 5 percent A typical soil description with range in Roy soils: 0 to 5 percent characteristics is included, in alphabetical order, in this section. Major Component Description Management Surface layer texture: Stony loam Depth class: Very deep (more than 60 inches) For management information about this map unit, Drainage class: Well drained see appropriate sections in Part II of this publication. 58 Soil Survey
342F—Braziel stony loam, Composition 35 to 60 percent slopes Major Components Braziel and similar soils: 60 percent Setting Tolbert and similar soils: 25 percent Landform: Mountains Minor Components Slope: 35 to 60 percent Areas of rock outcrop: 0 to 3 percent Elevation: 3,800 to 5,000 feet Soils that are moderately deep: 0 to 3 percent Mean annual precipitation: 15 to 19 inches Perma soils: 0 to 3 percent Frost-free period: 70 to 90 days Roy soils: 0 to 3 percent Soils that have slopes more than 15 percent: 0 to Composition 3 percent Major Components Major Component Description Braziel and similar soils: 85 percent Braziel Minor Components Surface layer texture: Stony loam Areas of rock outcrop: 0 to 5 percent Depth class: Very deep (more than 60 inches) Soils that are moderately deep: 0 to 5 percent Drainage class: Well drained Roy soils: 0 to 5 percent Dominant parent material: Material weathered from igneous rocks Major Component Description Native plant cover type: Rangeland Surface layer texture: Stony loam Flooding: None Depth class: Very deep (more than 60 inches) Available water capacity: Mainly 5.2 inches Drainage class: Well drained Dominant parent material: Material weathered from Tolbert igneous rocks Surface layer texture: Very stony loam Native plant cover type: Rangeland Depth class: Shallow (10 to 20 inches) Flooding: None Drainage class: Well drained Available water capacity: Mainly 5.2 inches Dominant parent material: Igneous residuum Native plant cover type: Rangeland A typical soil description with range in Flooding: None characteristics is included, in alphabetical order, in Available water capacity: Mainly 1.7 inches this section. A typical soil description with range in Management characteristics is included, in alphabetical order, in For management information about this map unit, this section. see appropriate sections in Part II of this publication. Management For management information about this map unit, 442D—Braziel-Tolbert complex, see appropriate sections in Part II of this publication. 8 to 15 percent slopes 442E—Braziel-Tolbert complex, Setting 15 to 35 percent slopes Landform: Setting • Braziel—Mountains • Tolbert—Mountains Landform: Slope: • Braziel—Mountains • Braziel—8 to 15 percent • Tolbert—Mountains • Tolbert—8 to 15 percent Slope: Elevation: 3,800 to 5,000 feet • Braziel—15 to 35 percent Mean annual precipitation: 15 to 19 inches • Tolbert—15 to 35 percent Frost-free period: 70 to 90 days Elevation: 3,800 to 5,000 feet Powell County Area, Montana—Part I 59
Mean annual precipitation: 15 to 19 inches Elevation: 3,800 to 5,000 feet Frost-free period: 70 to 90 days Mean annual precipitation: 15 to 19 inches Frost-free period: 70 to 90 days Composition Composition Major Components Braziel and similar soils: 60 percent Major Components Tolbert and similar soils: 25 percent Braziel and similar soils: 60 percent Tolbert and similar soils: 25 percent Minor Components Areas of rock outcrop: 0 to 3 percent Minor Components Soils that are moderately deep: 0 to 3 percent Areas of rock outcrop: 0 to 3 percent Soils that have a cobbly loam surface: 0 to 3 percent Soils that are moderately deep: 0 to 3 percent Roy soils: 0 to 3 percent Soils that have a cobbly loam surface: 0 to 3 percent Soils that have slopes more than 15 percent: 0 to Roy soils: 0 to 3 percent 3 percent Soils that have slopes more than 60 percent: 0 to 3 percent Major Component Description Braziel Major Component Description Surface layer texture: Stony loam Depth class: Very deep (more than 60 inches) Braziel Drainage class: Well drained Surface layer texture: Stony loam Dominant parent material: Material weathered from Depth class: Very deep (more than 60 inches) igneous rocks Drainage class: Well drained Native plant cover type: Rangeland Dominant parent material: Material weathered from Flooding: None igneous rocks Available water capacity: Mainly 5.2 inches Native plant cover type: Rangeland Flooding: None Tolbert Available water capacity: Mainly 5.2 inches Surface layer texture: Very stony loam Depth class: Shallow (10 to 20 inches) Tolbert Drainage class: Well drained Surface layer texture: Very stony loam Dominant parent material: Igneous residuum Depth class: Shallow (10 to 20 inches) Native plant cover type: Rangeland Drainage class: Well drained Flooding: None Dominant parent material: Igneous residuum Available water capacity: Mainly 1.7 inches Native plant cover type: Rangeland Flooding: None A typical soil description with range in Available water capacity: Mainly 1.7 inches characteristics is included, in alphabetical order, in this section. A typical soil description with range in characteristics is included, in alphabetical order, in Management this section. For management information about this map unit, Management see appropriate sections in Part II of this publication. For management information about this map unit, see appropriate sections in Part II of this publication. 442F—Braziel-Tolbert complex, 35 to 60 percent slopes 742E—Braziel-Perma-Water complex, Setting 8 to 25 percent slopes Landform: • Braziel—Mountains Setting • Tolbert—Mountains Slope: Landform: • Braziel—35 to 60 percent • Braziel—Moraines • Tolbert—35 to 60 percent • Perma—Moraines 60 Soil Survey
Slope: 742F—Braziel-Perma-Water complex, • Braziel—8 to 25 percent 25 to 50 percent slopes • Perma—8 to 25 percent Elevation: 3,800 to 5,000 feet Setting Mean annual precipitation: 15 to 19 inches Frost-free period: 70 to 90 days Landform: • Braziel—Moraines Composition • Perma—Moraines Major Components Slope: Braziel and similar soils: 50 percent • Braziel—25 to 50 percent Perma and similar soils: 20 percent • Perma—25 to 50 percent Water: 15 percent Elevation: 3,800 to 5,000 feet Mean annual precipitation: 15 to 19 inches Minor Components Frost-free period: 70 to 90 days Straw soils: 0 to 5 percent Martinsdale soils: 0 to 5 percent Composition Poorly drained soils: 0 to 5 percent Major Components Major Component Description Braziel and similar soils: 50 percent Perma and similar soils: 20 percent Braziel Water: 15 percent Surface layer texture: Gravelly loam Depth class: Very deep (more than 60 inches) Minor Components Drainage class: Well drained Straw soils: 0 to 5 percent Dominant parent material: Alpine till Martinsdale soils: 0 to 5 percent Native plant cover type: Rangeland Poorly drained soils: 0 to 5 percent Flooding: None Major Component Description Available water capacity: Mainly 5.6 inches Braziel Perma Surface layer texture: Gravelly loam Surface layer texture: Very cobbly loam Depth class: Very deep (more than 60 inches) Depth class: Very deep (more than 60 inches) Drainage class: Well drained Drainage class: Somewhat excessively drained Dominant parent material: Alpine till Dominant parent material: Glacial outwash Native plant cover type: Rangeland Native plant cover type: Rangeland Flooding: None Flooding: None Available water capacity: Mainly 5.6 inches Available water capacity: Mainly 3.8 inches Perma Water Surface layer texture: Very cobbly loam Definition: Areas of open water Depth class: Very deep (more than 60 inches) Drainage class: Somewhat excessively drained A typical soil description with range in Dominant parent material: Glacial outwash characteristics is included, in alphabetical order, in Native plant cover type: Rangeland this section. Flooding: None Available water capacity: Mainly 3.8 inches Management For management information about this map unit, Water see appropriate sections in Part II of this publication. Definition: Areas of open water Powell County Area, Montana—Part I 61
A typical soil description with range in plastic; many very fine and fine and common characteristics is included, in alphabetical order, in medium roots; common very fine and fine this section. discontinuous irregular pores; 10 percent cobbles and 20 percent pebbles; disseminated lime; Management violently effervescent; moderately alkaline; For management information about this map unit, gradual wavy boundary. see appropriate sections in Part II of this publication. 2C—15 to 60 inches; pale brown (10YR 6/3) extremely gravelly sand, brown (10YR 5/3) moist; many medium distinct brown (10YR 4/4) redox Bushong Series concentrations; single grain; loose, nonsticky, nonplastic; common very fine and fine and few Depth class: Very deep medium roots; common very fine and fine Drainage class: Poorly drained discontinuous irregular pores; 25 percent cobbles Permeability: Rapid and 50 percent pebbles; slightly alkaline. Landform: Stream terraces and flood plains Parent material: Alluvium Range in Characteristics Slope range: 0 to 4 percent Elevation range: 3,600 to 7,200 feet Soil temperature: 41 to 46 degrees F Annual precipitation: 10 to 22 inches Moisture control section: Between depths of 4 and Annual air temperature: 39 to 44 degrees F 12 inches Frost-free period: 30 to 105 days Depth to the seasonal high water table: 12 to 24 inches Taxonomic Class: Fine-loamy over sandy or sandy- Depth to the Bk horizon: 3 to 8 inches skeletal, mixed, superactive, calcareous, frigid Other features: The Bushong soil is a taxadjunct to Aeric Endoaquents the series in map unit 10 based on having a cryic temperature regime and similar use and Typical Pedon management. It classifies as fine-loamy over Bushong loam, 0 to 4 percent slopes, in an area of sandy or sandy-skeletal, mixed, superactive, pasture, 100 feet north and 500 feet east of the calcareous Typic Cryaquents. southwest corner of sec. 6, T. 6 N., R. 9 W. A horizon Oi—1.5 inches to 0; partially decomposed organic Hue: 10YR, 2.5Y, or 5Y matter. Value: 2 or 3 moist; 4 or 5 dry A—0 to 2 inches; dark grayish brown (10YR 4/2) Chroma: 1 or 2 loam, very dark grayish brown (10YR 3/2) moist; Clay content: 15 to 25 percent moderate fine granular structure; soft, very Content of rock fragments: 0 to 10 percent—0 to friable, nonsticky, nonplastic; many very fine 5 percent cobbles; 0 to 5 percent pebbles and fine and common medium roots; common Electrical conductivity: 0 to 2 mmhos/cm very fine and fine discontinuous irregular pores; Calcium carbonate equivalent: 0 to 5 percent 5 percent pebbles; moderately alkaline; clear Reaction: pH 7.4 to 8.4 smooth boundary. Bw horizon Bw—2 to 4 inches; brown (10YR 5/3) loam, dark Hue: 10YR or 2.5Y brown (10YR 3/3) moist; few fine faint dark Value: 3 or 4 moist; 4 or 5 dry yellowish brown (10YR 4/4) redox concentrations; Chroma: 2 or 3 moderate fine subangular blocky structure; soft, Texture: Loam or sandy loam very friable, slightly sticky, slightly plastic; many Clay content: 15 to 27 percent very fine and fine and common medium roots; Content of rock fragments: 5 to 35 percent—0 to common very fine and fine discontinuous 5 percent cobbles; 5 to 30 percent pebbles irregular pores; 5 percent pebbles; moderately Electrical conductivity: 0 to 2 mmhos/cm alkaline; clear smooth boundary. Calcium carbonate equivalent: 0 to 5 percent Bk—4 to 15 inches; pale brown (10YR 6/3) gravelly Reaction: pH 7.4 to 8.4 loam, brown (10YR 5/3) moist; many fine distinct brown (7.5YR 4/4) redox concentrations; Bk horizon moderate fine subangular blocky structure; Hue: 10YR or 2.5Y slightly hard, very friable, slightly sticky, slightly Value: 4 or 5 moist; 5 or 6 dry 62 Soil Survey
Chroma: 3 or 4 Management Texture: Sandy loam or loam For management information about this map unit, Clay content: 15 to 27 percent see appropriate sections in Part II of this publication. Content of rock fragments: 5 to 35 percent—0 to 15 percent cobbles; 5 to 20 percent pebbles Electrical conductivity: 0 to 2 mmhos/cm Calcium carbonate equivalent: 3 to 15 percent 632—Bushong loam, Reaction: pH 7.4 to 8.4 0 to 4 percent slopes 2C horizon Setting Value: 4 to 6 moist; 6 or 7 dry Chroma: 2 or 3 Landform: Stream terraces Texture: Sand or loamy sand Slope: 0 to 4 percent Clay content: 2 to 6 percent Elevation: 3,600 to 5,200 feet Content of rock fragments: 40 to 80 percent— Mean annual precipitation: 10 to 14 inches 10 to 25 percent cobbles; 30 to 55 percent Frost-free period: 90 to 105 days pebbles Composition Electrical conductivity: 0 to 2 mmhos/cm Reaction: pH 6.6 to 7.8 Major Components Bushong and similar soils: 85 percent 10—Bushong loam, taxadjunct, Minor Components 0 to 4 percent slopes Soils that have a very gravelly sandy texture: 0 to 8 percent Blossberg soils: 0 to 7 percent Setting Major Component Description Landform: Flood plains Slope: 0 to 4 percent Surface layer texture: Loam Elevation: 5,400 to 7,200 feet Depth class: Very deep (more than 60 inches) Mean annual precipitation: 15 to 22 inches Drainage class: Poorly drained Frost-free period: 30 to 70 days Dominant parent material: Alluvium Native plant cover type: Rangeland Composition Flooding: None Major Components Water table: Apparent Bushong and similar soils: 85 percent Available water capacity: Mainly 5.2 inches Minor Components A typical soil description with range in Somewhat poorly drained soils: 0 to 10 percent characteristics is included, in alphabetical order, in Areas of open water: 0 to 5 percent this section. Major Component Description Management Surface layer texture: Peat For management information about this map unit, Depth class: Very deep (more than 60 inches) see appropriate sections in Part II of this publication. Drainage class: Poorly drained Dominant parent material: Alluvium Native plant cover type: Rangeland 832—Bushong loam, 0 to 4 percent Flooding: Occasional slopes, rarely flooded Water table: Apparent Available water capacity: Mainly 11.7 inches Setting A typical soil description with range in Landform: Flood plains characteristics is included, in alphabetical order, in Slope: 0 to 4 percent this section. Elevation: 3,600 to 5,200 feet Powell County Area, Montana—Part I 63
Mean annual precipitation: 10 to 14 inches A—0 to 4 inches; very dark gray (10YR 3/1) gravelly Frost-free period: 90 to 105 days sandy loam, dark grayish brown (10YR 4/2) dry; moderate medium granular structure; slightly Composition hard, friable, slightly sticky, slightly plastic; Major Components many very fine and fine and common medium Bushong and similar soils: 85 percent roots; common very fine and fine tubular pores; 20 percent pebbles; strongly effervescent; Minor Components moderately alkaline; clear smooth boundary. Soils that are very gravelly below 8 inches: 0 to C1—4 to 8 inches; dark grayish brown (10YR 4/2) 4 percent gravelly coarse sandy loam, grayish brown (10YR Soils that have a clayey surface: 0 to 4 percent 5/2) dry; weak medium subangular blocky Very poorly drained soils: 0 to 4 percent structure; soft, very friable, nonsticky, nonplastic; Carten soils: 0 to 3 percent common fine and medium roots; common very Major Component Description fine tubular pores; 20 percent pebbles; slightly effervescent; moderately alkaline; clear smooth Surface layer texture: Loam boundary. Depth class: Very deep (more than 60 inches) C2—8 to 10 inches; dark grayish brown (10YR 4/2) Drainage class: Poorly drained gravelly sandy loam, grayish brown (10YR 5/2) Dominant parent material: Alluvium dry; weak medium subangular blocky structure; Native plant cover type: Rangeland soft, very friable, nonsticky, nonplastic; common Flooding: Rare very fine and fine and few medium roots; Water table: Apparent common very fine tubular pores; 20 percent Available water capacity: Mainly 5.2 inches pebbles; slightly effervescent; slightly alkaline; clear smooth boundary. A typical soil description with range in 2C3—10 to 60 inches; dark grayish brown (10YR 4/2) characteristics is included, in alphabetical order, in very gravelly sand, grayish brown (10YR 5/2) dry; this section. many fine faint yellowish brown (10YR 5/6) redox Management concentrations; single grain; loose, nonsticky, nonplastic; few fine roots; 20 percent cobbles and For management information about this map unit, 35 percent pebbles; slightly alkaline. see appropriate sections in Part II of this publication. Range in Characteristics Canarway Series Soil temperature: 41 to 46 degrees F Depth class: Very deep (greater than 60 inches) Moisture control section: Between depths of 12 and Drainage class: Poorly drained 35 inches Permeability: Very rapid Depth to the seasonal high water table: 12 to Landform: Flood plains 24 inches Parent material: Alluvium A horizon Slope range: 0 to 2 percent Value: 2 or 3 moist; 3 to 5 dry Elevation range: 4,000 to 4,100 feet Chroma: 1 to 3 Annual precipitation: 10 to 14 inches Clay content: 5 to 15 percent Annual air temperature: 39 to 44 degrees F Content of rock fragments: 0 to 25 percent—0 to Frost-free period: 90 to 105 days 5 percent cobbles; 0 to 20 percent pebbles Calcium carbonate equivalent: 0 to 5 percent Taxonomic Class: Sandy-skeletal, mixed, frigid Aeric Reaction: pH 6.6 to 8.4 Fluvaquents C1 horizon Typical Pedon Value: 4 or 5 moist; 5 or 6 dry Canarway gravelly sandy loam, in an area of Chroma: 2 or 3 Mccabe-Canarway complex, 0 to 2 percent slopes, Texture: Loamy sand or coarse sandy loam occasionally flooded, in an area of pasture, 1,100 feet Clay content: 5 to 15 percent north and 1,900 feet east of the southwest corner of Content of rock fragments: 0 to 25 percent—0 to sec. 14, T. 10 N., R. 12 W. 5 percent cobbles; 0 to 20 percent pebbles 64 Soil Survey
Calcium carbonate equivalent: 0 to 5 percent Bw—7 to 11 inches; pale brown (10YR 6/3) loam, Reaction: pH 6.6 to 8.4 brown (10YR 5/3) moist; moderate medium granular structure; soft, very friable, slightly sticky, C2 horizon moderately plastic; many very fine and fine roots; Value: 4 or 5 moist; 5 or 6 dry common very fine and fine random irregular Chroma: 2 or 3 pores; 5 percent cobbles and 5 percent pebbles; Texture: Sandy loam or sand strongly effervescent; moderately alkaline; clear Clay content: 0 to 15 percent smooth boundary. Content of rock fragments: 0 to 25 percent—0 to Bk—11 to 17 inches; brown (10YR 4/3) gravelly loam, 5 percent cobbles; 0 to 20 percent pebbles dark brown (10YR 3/3) moist; weak medium Calcium carbonate equivalent: 0 to 5 percent subangular blocky structure parting to moderate Reaction: pH 7.4 to 7.8 medium granular structure; slightly hard, friable, 2C3 horizon slightly sticky, slightly plastic; many very fine and Value: 4 or 5 moist; 5 or 6 dry common fine roots; common very fine and fine Chroma: 2 or 3 and few medium constricted random irregular Texture: Loamy sand or sand pores; 5 percent cobbles and 15 percent pebbles; Clay content: 0 to 10 percent disseminated lime; violently effervescent; Content of rock fragments: 35 to 60 percent— moderately alkaline; gradual smooth boundary. 10 to 25 percent cobbles; 25 to 35 percent 2C1—17 to 27 inches; brown (10YR 5/3) very gravelly pebbles loamy sand, brown (10YR 4/3) moist; few fine Reaction: pH 6.6 to 7.8 faint strong brown (7.5YR 4/6) redox concentrations; massive; soft, very friable, nonsticky, nonplastic; few very fine and fine roots; Carten Series many very fine and fine and common medium discontinuous irregular pores; 15 percent cobbles Depth class: Very deep and 35 percent pebbles; strongly effervescent; Drainage class: Somewhat poorly drained slightly alkaline; gradual wavy boundary. Permeability: Moderately slow to the 2C horizon, 2C2—27 to 60 inches; brown (10YR 5/3) extremely rapid below gravelly loamy sand, brown (10YR 4/3) moist; Landform: Outwash plains and flood plains few fine faint strong brown (7.5YR 4/6) redox Parent material: Alluvium concentrations; single grain; loose, nonsticky, Slope range: 0 to 4 percent nonplastic; few very fine roots; many very fine Elevation range: 3,600 to 6,000 feet and medium discontinuous irregular pores; Annual precipitation: 10 to 19 inches 20 percent cobbles and 50 percent pebbles; Annual air temperature: 39 to 44 degrees F slightly alkaline. Frost-free period: 70 to 105 days Range in Characteristics Taxonomic Class: Fine-loamy over sandy or sandy- skeletal, mixed, superactive, frigid Oxyaquic Soil temperature: 43 to 47 degrees F Haplustolls Moisture control section: Between depths of 4 and 12 inches Typical Pedon Thickness of the mollic epipedon: 7 to 12 inches Carten loam, 0 to 4 percent slopes, in an area of Depth to the seasonal high water table: 24 to pasture, 1,000 feet south and 1,500 feet east of the 42 inches northwest corner of sec. 2, T. 7 N., R. 10 W. Depth to the Bk horizon: 9 to 13 inches Depth to the 2C horizon: 12 to 20 inches A—0 to 7 inches; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; weak A horizon medium granular structure; soft, very friable, Value: 4 or 5 dry; 2 or 3 moist slightly sticky, slightly plastic; many very fine and Chroma: 2 or 3 fine and common medium roots; common very Clay content: 18 to 27 percent fine and fine random irregular pores; 5 percent Content of rock fragments: 0 to 15 percent—0 to cobbles and 5 percent pebbles; slightly alkaline; 5 percent cobbles; 0 to 10 percent pebbles clear wavy boundary. Reaction: pH 6.6 to 7.8 Powell County Area, Montana—Part I 65
Bw horizon Major Component Description Value: 4 to 6 dry; 3 to 5 moist Carten Chroma: 3 or 4 Surface layer texture: Loam Texture: Loam or clay loam Depth class: Very deep (more than 60 inches) Clay content: 20 to 30 percent Drainage class: Somewhat poorly drained Content of rock fragments: 0 to 30 percent—0 to Dominant parent material: Alluvium 5 percent cobbles; 0 to 25 percent pebbles Native plant cover type: Rangeland Reaction: pH 7.4 to 8.4 Flooding: Rare Bk horizon Water table: Apparent Value: 4 to 8 dry; 3 to 7 moist Available water capacity: Mainly 4.4 inches Chroma: 2 to 4 Texture: Loam or clay loam Wetsand Clay content: 20 to 30 percent Surface layer texture: Loam Content of rock fragments: 15 to 35 percent—0 to Depth class: Very deep (more than 60 inches) 10 percent cobbles; 15 to 25 percent pebbles Drainage class: Poorly drained Calcium carbonate equivalent: 5 to 15 percent Dominant parent material: Alluvium Reaction: pH 7.4 to 8.4 Native plant cover type: Rangeland Flooding: Rare 2C horizons Water table: Apparent Value: 5 to 7 dry; 4 to 6 moist Salt affected: Saline within 30 inches Chroma: 2 to 4 Available water capacity: Mainly 3.8 inches Texture: Loamy sand or sand Clay content: 2 to 10 percent A typical soil description with range in Content of rock fragments: 40 to 80 percent— characteristics is included, in alphabetical order, in 10 to 25 percent cobbles; 30 to 55 percent this section. pebbles Reaction: pH 7.4 to 8.4 Management For management information about this map unit, 110—Carten-Wetsand complex, 0 to 2 see appropriate sections in Part II of this publication. percent slopes, rarely flooded
Setting 432—Carten loam, 0 to 4 percent slopes, rarely flooded Landform: • Carten—Flood plains • Wetsand—Flood plains Setting Slope: Landform: Flood plains • Carten—0 to 2 percent Slope: 0 to 4 percent • Wetsand—0 to 2 percent Elevation: 3,600 to 5,200 feet Elevation: 4,200 to 6,000 feet Mean annual precipitation: 15 to 19 inches Mean annual precipitation: 10 to 19 inches Frost-free period: 70 to 90 days Frost-free period: 70 to 105 days Composition Composition Major Components Major Components Carten and similar soils: 45 percent Carten and similar soils: 85 percent Wetsand and similar soils: 40 percent Minor Components Minor Components Soils that are very gravelly below 10 inches: 0 to Areas of open water: 0 to 6 percent 5 percent Areas of riverwash: 0 to 5 percent Poorly drained soils: 0 to 5 percent Soils that are not flooded: 0 to 4 percent Soils that have a cobbly loam surface: 0 to 5 percent 66 Soil Survey
Major Component Description 562—Carten loam, 0 to 4 percent slopes Surface layer texture: Loam Depth class: Very deep (more than 60 inches) Setting Drainage class: Somewhat poorly drained Landform: Outwash plains Dominant parent material: Alluvium Slope: 0 to 4 percent Native plant cover type: Rangeland Elevation: 3,600 to 5,200 feet Flooding: Rare Mean annual precipitation: 10 to 14 inches Water table: Apparent Frost-free period: 90 to 105 days Available water capacity: Mainly 4.4 inches A typical soil description with range in Composition characteristics is included, in alphabetical order, in this section. Major Components Management Carten and similar soils: 85 percent For management information about this map unit, Minor Components see appropriate sections in Part II of this publication. Poorly drained soils: 0 to 15 percent
Major Component Description 532—Carten loam, cool, 0 to 4 percent slopes Surface layer texture: Loam Depth class: Very deep (more than 60 inches) Setting Drainage class: Somewhat poorly drained Dominant parent material: Alluvium Landform: Outwash plains Native plant cover type: Rangeland Slope: 0 to 4 percent Flooding: None Elevation: 3,600 to 5,200 feet Water table: Apparent Mean annual precipitation: 15 to 19 inches Available water capacity: Mainly 4.4 inches Frost-free period: 70 to 90 days Composition A typical soil description with range in characteristics is included, in alphabetical order, in Major Components this section. Carten and similar soils: 85 percent Management Minor Components Poorly drained soils: 0 to 15 percent For management information about this map unit, see appropriate sections in Part II of this publication. Major Component Description Surface layer texture: Loam Depth class: Very deep (more than 60 inches) Castner Series Drainage class: Somewhat poorly drained Dominant parent material: Alluvium Depth class: Shallow Native plant cover type: Rangeland Drainage class: Well drained Flooding: None Permeability: Moderate Water table: Apparent Landform: Hills Available water capacity: Mainly 4.4 inches Parent material: Sandstone residuum Slope range: 0 to 45 percent A typical soil description with range in Elevation range: 3,600 to 5,200 feet characteristics is included, in alphabetical order, in Annual precipitation: 10 to 14 inches this section. Annual air temperature: 39 to 44 degrees F Frost-free period: 90 to 105 days Management For management information about this map unit, Taxonomic Class: Loamy-skeletal, mixed, see appropriate sections in Part II of this publication. superactive, frigid Lithic Haplustolls Powell County Area, Montana—Part I 67
Typical Pedon Clay content: 10 to 18 percent, with less than 35 percent fine and coarser sand Castner channery loam, in an area of Dolus-Castner Content of rock fragments: 35 to 70 percent—5 to channery loams, 15 to 45 percent slopes, in an area 20 percent cobbles and flagstones; 30 to of rangeland, 100 feet south and 375 feet west of the 55 percent pebbles and channers northeast corner of sec. 20, T. 9 N., R. 9 W. Reaction: pH 6.6 to 8.4 A—0 to 8 inches; brown (10YR 5/3) channery loam, Bk horizon dark brown (10YR 3/3) moist; weak medium Hue: 2.5Y, 10YR, 7.5YR, or 5YR granular structure; soft, very friable, nonsticky, Value: 4 to 6 dry; 3 to 5 moist nonplastic; many fine roots; many very fine Chroma: 2 or 3 discontinuous random pores; 5 percent Texture: Loam or sandy loam flagstones and 30 percent channers; neutral; Clay content: 10 to 18 percent, with less than clear smooth boundary. 35 percent fine and coarser sand Bw—8 to 12 inches; brown (10YR 5/3) extremely Content of rock fragments: 35 to 80 percent— channery loam, brown (10YR 4/3) moist; weak 10 to 25 percent cobbles and flagstones; 25 to medium subangular blocky structure; soft, very 60 percent pebbles and channers friable, nonsticky, nonplastic; common very Calcium carbonate equivalent: 3 to 15 percent fine roots; common very fine continuous pores; Electrical conductivity: 0 to 2 mmhos/cm 20 percent flagstones and 40 percent channers; Reaction: pH 7.4 to 8.4 neutral; clear smooth boundary. Bk—12 to 16 inches; light brownish gray (2.5Y 6/2) extremely channery loam, grayish brown (2.5Y Cetrack Series 5/2) moist; weak fine subangular blocky structure; soft, very friable, nonsticky, nonplastic; common Depth class: Very deep very fine roots; few very fine continuous pores; Drainage class: Well drained 25 percent flagstones and 50 percent channers; Permeability: Moderate to the 2C horizon, rapid below disseminated lime; strongly effervescent; Landform: Alluvial fans and stream terraces moderately alkaline. Parent material: Calcareous alluvium R—16 inches; hard shattered sandstone. Slope range: 0 to 15 percent Elevation range: 3,600 to 5,000 feet Range in Characteristics Annual precipitation: 10 to 14 inches Annual air temperature: 40 to 44 degrees F Soil temperature: 41 to 47 degrees F Frost-free period: 90 to 105 days Moisture control section: Between depths of 4 and 12 inches Taxonomic Class: Fine-loamy over sandy or sandy- Thickness of the mollic epipedon: 7 to 15 inches skeletal, mixed, superactive, frigid Aridic Depth to bedrock: 10 to 20 inches Haplustolls Depth to the k horizon: 7 to 15 inches Typical Pedon A horizon Hue: 2.5Y, 10YR, 7.5YR, or 5YR Cetrack loam, 0 to 4 percent slopes, in an area of Value: 3 to 5 dry; 2 or 3 moist cropland, 950 feet south and 1,100 feet west of the Chroma: 1 to 3 northeast corner of sec. 20, T. 7 N., R. 9 W. Clay content: 10 to 18 percent, with less than Ap—0 to 6 inches; brown (10YR 5/3) loam, dark 35 percent fine and coarser sand brown (10YR 3/3) moist; moderate thick platy Content of rock fragments: 15 to 35 percent—0 to structure; slightly hard, very friable, moderately 5 percent flagstones; 15 to 30 percent sticky, slightly plastic; many very fine, fine, and channers medium roots; few medium tubular pores; neutral; Reaction: pH 6.6 to 7.8 abrupt smooth boundary. Bw horizon Bw—6 to 11 inches; brown (10YR 5/3) loam, dark Hue: 2.5Y, 10YR, 7.5YR, or 5YR brown (10YR 4/3) moist; moderate medium Value: 3 to 5 dry; 2 to 4 moist subangular blocky structure; slightly hard, friable, Chroma: 1 to 3 moderately sticky, moderately plastic; common Texture: Loam or sandy loam very fine, fine, and medium roots; common very 68 Soil Survey
fine and fine tubular pores; slightly alkaline; clear Chroma: 2 or 3 wavy boundary. Texture: Loam or clay loam Bk1—11 to 16 inches; pale brown (10YR 6/3) loam, Clay content: 22 to 32 percent brown (10YR 5/3) moist; weak medium Content of rock fragments: 0 to 20 percent—0 to subangular blocky structure; slightly hard, very 5 percent cobbles; 0 to 15 percent pebbles friable, slightly sticky, slightly plastic; common Reaction: pH 6.6 to 7.8 very fine, fine, and medium roots; common very Bk1 horizon fine and fine tubular pores; 5 percent pebbles; Hue: 10YR or 2.5Y disseminated lime; strongly effervescent; Value: 6 or 7 dry; 4 or 5 moist moderately alkaline; gradual wavy boundary. Chroma: 2 or 3 Bk2—16 to 26 inches; very pale brown (10YR 8/3) Clay content: 18 to 25 percent loam, pale brown (10YR 6/3) moist; weak Content of rock fragments: 5 to 20 percent—0 to medium subangular blocky structure; slightly 5 percent cobbles; 5 to 15 percent pebbles hard, very friable, slightly sticky, slightly plastic; Calcium carbonate equivalent: 5 to 20 percent common very fine, fine, and medium roots; Reaction: pH 7.4 to 8.4 common very fine irregular pores; 5 percent pebbles; disseminated lime; violently Bk2 and Bk3 horizons effervescent; moderately alkaline; gradual wavy Hue: 10YR or 2.5Y boundary. Value: 7 or 8 dry; 5 or 6 moist Bk3—26 to 30 inches; very pale brown (10YR 7/3) Chroma: 2 or 3 sandy loam, pale brown (10YR 6/3) moist; weak Clay content: 18 to 25 percent medium subangular blocky structure; soft, very Content of rock fragments: 5 to 25 percent—0 to friable, nonsticky, slightly plastic; common very 5 percent cobbles; 5 to 20 percent pebbles fine, fine, and medium roots; 10 percent pebbles; Calcium carbonate equivalent: 15 to 30 percent disseminated lime; violently effervescent; Reaction: pH 7.9 to 8.4 moderately alkaline; abrupt smooth boundary. 2C horizon 2C—30 to 60 inches; very pale brown (10YR 7/3) Hue: 10YR or 2.5Y very gravelly loamy sand, pale brown (10YR 6/3) Value: 5 to 7 dry; 4 to 6 moist moist; single grain; loose, soft, nonsticky, Chroma: 2 to 4 nonplastic; few very fine, fine, and medium roots; Texture: Loamy sand or sand 35 percent pebbles; few faint lime casts on Clay content: 0 to 10 percent underside of coarse fragments; slightly alkaline. Content of rock fragments: 35 to 70 percent—0 to 20 percent cobbles; 35 to 50 percent pebbles Range in Characteristics Reaction: pH 7.4 to 8.4 Soil temperature: 42 to 47 degrees F Moisture control section: Between depths of 8 and 12 inches; dry in all parts less than five-tenths 34B—Cetrack loam, 0 to 4 percent slopes and dry in some part more than six-tenths of the cumulative days per year when the soil Setting temperature at a depth of 20 inches is Landform: Alluvial fans and stream terraces 41 degrees F or higher Slope: 0 to 4 percent Thickness of the mollic epipedon: 7 to 14 inches Elevation: 3,600 to 5,000 feet Depth to very gravelly material: 20 to 40 inches Mean annual precipitation: 10 to 14 inches Depth to the calcic horizon: 8 to 14 inches Frost-free period: 90 to 105 days Ap horizon Composition Chroma: 2 or 3 Clay content: 15 to 25 percent Major Components Content of rock fragments: 0 to 15 percent—0 to Cetrack and similar soils: 85 percent 5 percent cobbles; 0 to 10 percent pebbles Minor Components Reaction: pH 6.1 to 7.8 Soils that have slopes more than 4 percent: 0 to Bw horizon 3 percent Hue: 7.5YR, 10YR, or 2.5Y Somewhat poorly drained soils: 0 to 3 percent Value: 5 or 6 dry; 3 or 4 moist Cetrack cobbly loam: 0 to 3 percent Powell County Area, Montana—Part I 69
Soils that are very gravelly: 0 to 3 percent Management Soils that have a calcareous surface layer: 0 to For management information about this map unit, 3 percent see appropriate sections in Part II of this publication. Major Component Description Surface layer texture: Loam Clasoil Series Depth class: Very deep (more than 60 inches) Drainage class: Well drained Depth class: Very deep Dominant parent material: Alluvium Drainage class: Well drained Native plant cover type: Rangeland Permeability: Moderate Flooding: None Landform: Mountains, alluvial fans, and stream Available water capacity: Mainly 5.7 inches terraces Parent material: Alluvium and colluvium derived from A typical soil description with range in granite and other coarse-grained igneous rocks characteristics is included, in alphabetical order, in Slope range: 0 to 35 percent this section. Elevation range: 3,500 to 5,200 feet Annual precipitation: 15 to 19 inches Management Annual air temperature: 39 to 44 degrees F For management information about this map unit, Frost-free period: 70 to 90 days see appropriate sections in Part II of this publication. Taxonomic Class: Fine-loamy, mixed, superactive, frigid Typic Argiustolls 34C—Cetrack loam, 4 to 8 percent slopes Typical Pedon Setting Clasoil sandy loam, in an area of Clasoil-Crackerville Landform: Alluvial fans and stream terraces complex, 15 to 35 percent slopes, in an area of Slope: 4 to 8 percent rangeland, 400 feet south and 2,200 feet east of the Elevation: 3,600 to 5,000 feet northwest corner of sec. 8, T. 6 N., R. 8 W. Mean annual precipitation: 10 to 14 inches A—0 to 11 inches; dark grayish brown (10YR 4/2) Frost-free period: 90 to 105 days sandy loam, very dark brown (10YR 2/2) moist; Composition weak fine subangular blocky structure parting to weak fine granular structure; soft, friable, Major Components nonsticky, nonplastic; many very fine and fine and Cetrack and similar soils: 85 percent few medium roots; many very fine continuous Minor Components irregular pores; 5 percent cobbles and 5 percent Soils that have slopes more than 8 percent: 0 to pebbles; moderately acid; clear smooth boundary. 5 percent Bt1—11 to 16 inches; brown (10YR 5/3) gravelly Cetrack cobbly loam: 0 to 5 percent sandy clay loam, brown (10YR 4/3), dark Soils that are very gravelly: 0 to 5 percent yellowish brown (10YR 4/4) moist; moderate medium prismatic structure parting to moderate Major Component Description medium subangular blocky; slightly hard, friable, Surface layer texture: Loam nonsticky, slightly plastic; many very fine and fine Depth class: Very deep (more than 60 inches) and few medium roots; many very fine continuous Drainage class: Well drained irregular pores; few faint clay films on faces of Dominant parent material: Alluvium peds; 20 percent pebbles; slightly acid; clear Native plant cover type: Rangeland smooth boundary. Flooding: None Bt2—16 to 20 inches; yellowish brown (10YR 5/4) Available water capacity: Mainly 5.7 inches gravelly sandy clay loam, dark yellowish brown (10YR 4/4) moist; moderate medium prismatic A typical soil description with range in structure parting to moderate medium subangular characteristics is included, in alphabetical order, in blocky; slightly hard, friable, nonsticky, slightly this section. plastic; many very fine and fine and few medium 70 Soil Survey
roots; many very fine continuous irregular pores; Clay content: 12 to 20 percent few faint clay films on faces of peds; 5 percent Content of rock fragments: 15 to 40 percent—0 to cobbles and 20 percent pebbles; slightly alkaline; 20 percent stones and cobbles; 15 to clear smooth boundary. 35 percent pebbles Bt3—20 to 31 inches; yellowish brown (10YR 5/4) Reaction: pH 6.1 to 7.8 gravelly sandy loam, dark yellowish brown (10YR 4/4) moist; weak medium subangular blocky structure; slightly hard, friable, nonsticky, slightly 152B—Clasoil sandy loam, plastic; many very fine, common fine, and few 0 to 4 percent slopes medium roots; common very fine continuous irregular pores; common distinct clay bridging Setting between sand grains; 5 percent cobbles and 25 percent pebbles; slightly alkaline; clear Landform: Alluvial fans and stream terraces smooth boundary. Slope: 0 to 4 percent Elevation: 3,500 to 5,200 feet BC—31 to 60 inches; yellowish brown (10YR 5/4) Mean annual precipitation: 15 to 19 inches very gravelly sandy loam, dark yellowish brown Frost-free period: 70 to 90 days (10YR 4/4) moist; weak fine and medium subangular blocky structure; slightly hard, friable, Composition nonsticky, nonplastic; common very fine and Major Components fine and few medium roots; common very fine Clasoil and similar soils: 85 percent continuous pores; 10 percent cobbles and 30 percent pebbles; slightly alkaline. Minor Components Very gravelly loamy soils: 0 to 8 percent Range in Characteristics Soils that have slopes more than 8 percent: 0 to Soil temperature: 38 to 43 degrees F 7 percent Moisture control section: Between depths of 4 and Major Component Description 12 inches Thickness of the mollic epipedon: 7 to 15 inches Surface layer texture: Sandy loam Depth to the argillic horizon: 7 to 22 inches Depth class: Very deep (more than 60 inches) Drainage class: Well drained A horizon Dominant parent material: Alluvium or colluvium Hue: 10YR or 2.5Y Native plant cover type: Rangeland Value: 2 to 4 dry; 2 or 3 moist Flooding: None Chroma: 2 or 3 Available water capacity: Mainly 7.6 inches Clay content: 12 to 20 percent Content of rock fragments: 0 to 15 percent A typical soil description with range in pebbles characteristics is included, in alphabetical order, in Reaction: pH 5.6 to 7.3 this section. Bt horizons Management Hue: 10YR or 2.5Y Value: 5 or 6 dry; 4 or 5 moist For management information about this map unit, Chroma: 2 to 4 see appropriate sections in Part II of this publication. Texture: Sandy clay loam, loam, or clay loam Clay content: 18 to 30 percent Content of rock fragments: 5 to 35 percent—0 to 152C—Clasoil sandy loam, 15 percent stones and cobbles; 5 to 30 percent 4 to 8 percent slopes pebbles Reaction: pH 5.6 to 7.3 Setting BC horizon Landform: Alluvial fans and stream terraces Hue: 10YR or 2.5Y Slope: 4 to 8 percent Value: 5 or 6 dry; 4 or 5 moist Elevation: 3,500 to 5,200 feet Chroma: 3, 4, or 6 Mean annual precipitation: 15 to 19 inches Texture: Sandy loam, loam, or coarse sandy loam Frost-free period: 70 to 90 days Powell County Area, Montana—Part I 71
Composition A typical soil description with range in characteristics is included, in alphabetical order, in Major Components this section. Clasoil and similar soils: 85 percent Management Minor Components Very gravelly loamy soils: 0 to 8 percent For management information about this map unit, Soils that have slopes more than 8 percent: 0 to see appropriate sections in Part II of this publication. 7 percent Major Component Description 552C—Clasoil-Crackerville complex, Surface layer texture: Sandy loam 4 to 8 percent slopes Depth class: Very deep (more than 60 inches) Drainage class: Well drained Dominant parent material: Alluvium or colluvium Setting Native plant cover type: Rangeland Landform: Flooding: None • Clasoil—Mountains Available water capacity: Mainly 7.6 inches • Crackerville—Mountains Slope: A typical soil description with range in • Clasoil—4 to 8 percent characteristics is included, in alphabetical order, in • Crackerville—4 to 8 percent this section. Elevation: 3,500 to 5,200 feet Management Mean annual precipitation: 15 to 19 inches Frost-free period: 70 to 90 days For management information about this map unit, see appropriate sections in Part II of this publication. Composition Major Components 152D—Clasoil sandy loam, Clasoil and similar soils: 50 percent 8 to 15 percent slopes Crackerville and similar soils: 35 percent Minor Components Setting Soils that are shallow to bedrock: 0 to 5 percent Areas of rock outcrop: 0 to 5 percent Landform: Alluvial fans and stream terraces Soils that have a stony surface: 0 to 5 percent Slope: 8 to 15 percent Elevation: 3,500 to 5,200 feet Major Component Description Mean annual precipitation: 15 to 19 inches Clasoil Frost-free period: 70 to 90 days Surface layer texture: Sandy loam Composition Depth class: Very deep (more than 60 inches) Drainage class: Well drained Major Components Dominant parent material: Alluvium Clasoil and similar soils: 85 percent Native plant cover type: Rangeland Minor Components Flooding: None Very gravelly loamy soils: 0 to 8 percent Available water capacity: Mainly 7.5 inches Areas of rock outcrop: 0 to 7 percent Crackerville Major Component Description Surface layer texture: Loam Surface layer texture: Sandy loam Depth class: Moderately deep (20 to 40 inches) Depth class: Very deep (more than 60 inches) Drainage class: Well drained Drainage class: Well drained Dominant parent material: Material weathered from Dominant parent material: Alluvium or colluvium granitic rocks Native plant cover type: Rangeland Native plant cover type: Rangeland Flooding: None Flooding: None Available water capacity: Mainly 7.6 inches Available water capacity: Mainly 2.7 inches 72 Soil Survey
A typical soil description with range in A typical soil description with range in characteristics is included, in alphabetical order, in characteristics is included, in alphabetical order, in this section. this section. Management Management For management information about this map unit, For management information about this map unit, see appropriate sections in Part II of this publication. see appropriate sections in Part II of this publication.
552D—Clasoil-Crackerville complex, 552E—Clasoil-Crackerville complex, 8 to 15 percent slopes 15 to 35 percent slopes Setting Setting Landform: • Clasoil—Mountains Landform: • Crackerville—Mountains • Clasoil—Mountains Slope: • Crackerville—Mountains • Clasoil—8 to 15 percent Slope: • Crackerville—8 to 15 percent • Clasoil—15 to 35 percent Elevation: 3,500 to 5,200 feet • Crackerville—15 to 35 percent Mean annual precipitation: 15 to 19 inches Elevation: 3,500 to 5,200 feet Frost-free period: 70 to 90 days Mean annual precipitation: 15 to 19 inches Frost-free period: 70 to 90 days Composition Composition Major Components Clasoil and similar soils: 50 percent Major Components Crackerville and similar soils: 35 percent Clasoil and similar soils: 50 percent Crackerville and similar soils: 35 percent Minor Components Soils that are shallow to bedrock: 0 to 5 percent Minor Components Areas of rock outcrop: 0 to 5 percent Soils that are shallow to bedrock: 0 to 5 percent Soils that have a stony surface: 0 to 5 percent Areas of rock outcrop: 0 to 5 percent Soils that have a stony surface: 0 to 5 percent Major Component Description Major Component Description Clasoil Surface layer texture: Sandy loam Clasoil Depth class: Very deep (more than 60 inches) Surface layer texture: Sandy loam Drainage class: Well drained Depth class: Very deep (more than 60 inches) Dominant parent material: Alluvium Drainage class: Well drained Native plant cover type: Rangeland Dominant parent material: Alluvium Flooding: None Native plant cover type: Rangeland Available water capacity: Mainly 7.5 inches Flooding: None Available water capacity: Mainly 7.5 inches Crackerville Surface layer texture: Loam Crackerville Depth class: Moderately deep (20 to 40 inches) Surface layer texture: Loam Drainage class: Well drained Depth class: Moderately deep (20 to 40 inches) Dominant parent material: Material weathered from Drainage class: Well drained granitic rocks Dominant parent material: Colluvium Native plant cover type: Rangeland Native plant cover type: Rangeland Flooding: None Flooding: None Available water capacity: Mainly 2.7 inches Available water capacity: Mainly 2.7 inches Powell County Area, Montana—Part I 73
A typical soil description with range in Flooding: None characteristics is included, in alphabetical order, in Available water capacity: Mainly 2.7 inches this section. Rock outcrop Management Definition: Areas of exposed bedrock For management information about this map unit, see appropriate sections in Part II of this publication. A typical soil description with range in characteristics is included, in alphabetical order, in this section. 752E—Clasoil-Crackerville-Rock outcrop Management complex, 15 to 35 percent slopes For management information about this map unit, see appropriate sections in Part II of this publication. Setting Landform: Coben Series • Clasoil—Mountains • Crackerville—Mountains Depth class: Very deep • Rock outcrop—Mountains Drainage class: Well drained Slope: Permeability: Slow • Clasoil—15 to 35 percent Landform: Alluvial fans and stream terraces • Crackerville—15 to 35 percent Parent material: Alluvium Elevation: 3,500 to 5,200 feet Slope range: 0 to 15 percent Mean annual precipitation: 15 to 19 inches Elevation range: 4,000 to 5,200 feet Frost-free period: 70 to 90 days Annual precipitation: 15 to 19 inches Annual air temperature: 39 to 44 degrees F Composition Frost-free period: 70 to 90 days Major Components Clasoil and similar soils: 40 percent Taxonomic Class: Fine, smectitic, frigid Vertic Crackerville and similar soils: 30 percent Argiustolls Rock outcrop: 15 percent Typical Pedon Minor Components Coben loam, 4 to 8 percent slopes, in an area of Soils that have a stony surface: 0 to 5 percent cropland, 1,700 feet north and 2,475 feet east of the Soils that are shallow to bedrock: 0 to 5 percent southwest corner of sec. 21, T. 12 N., R. 12 W. Soils that have slopes more than 35 percent: 0 to 5 percent Ap1—0 to 4 inches; dark grayish brown (10YR 4/2) loam, very dark grayish brown (10YR 3/2) moist; Major Component Description weak medium granular structure; slightly hard, Clasoil friable, slightly sticky, slightly plastic; many very Surface layer texture: Sandy loam fine and common fine and medium roots; many Depth class: Very deep (more than 60 inches) very fine and common fine continuous random Drainage class: Well drained pores; 5 percent pebbles; slightly acid; clear Dominant parent material: Alluvium smooth boundary. Native plant cover type: Rangeland Ap2—4 to 6 inches; dark grayish brown (10YR 4/2) Flooding: None loam, very dark grayish brown (10YR 3/2) moist; Available water capacity: Mainly 7.5 inches weak medium subangular blocky structure; slightly hard, firm, slightly sticky, slightly plastic; Crackerville common very fine, fine, and medium roots; Surface layer texture: Loam common very fine and fine continuous random Depth class: Moderately deep (20 to 40 inches) pores; 5 percent pebbles; neutral; abrupt smooth Drainage class: Well drained boundary. Dominant parent material: Material weathered from Bt1—6 to 12 inches; grayish brown (10YR 5/2) clay, granitic rocks dark grayish brown (10YR 4/2) moist; strong Native plant cover type: Rangeland medium and coarse columnar structure; 74 Soil Survey
extremely hard, extremely firm, very sticky, very Sodium adsorption ratio: 0 to 8 percent plastic; few very fine and fine roots; few very fine Reaction: pH 6.6 to 8.4 continuous random tubular pores; many distinct Bk horizon clay films on faces of peds and lining pores; Hue: 10YR or 2.5Y 5 percent pebbles; neutral; gradual smooth Value: 5 or 6 dry; 4 or 5 moist boundary. Chroma: 3 or 4 Bt2—12 to 23 inches; brown (10YR 5/3) clay, brown Texture: Clay, clay loam, or silty clay loam (10YR 4/3) moist; strong medium prismatic Clay content: 30 to 45 percent structure; extremely hard, extremely firm, very Content of rock fragments: 0 to 10 percent sticky, very plastic; few very fine and fine roots; pebbles few very fine continuous random tubular pores; Calcium carbonate equivalent: 5 to 15 percent continuous distinct clay films on faces of peds Reaction: pH 7.4 to 8.4 and lining pores; 5 percent pebbles; neutral; gradual wavy boundary. BC horizon Bk—23 to 30 inches; pale brown (10YR 6/3) clay Value: 5 to 7 dry; 4 or 5 moist loam, brown (10YR 4/3) moist; weak medium Chroma: 3 or 4 subangular blocky structure parting to moderate Texture: Clay loam or loam medium granular structure; very hard, very firm, Clay content: 20 to 35 percent moderately sticky, moderately plastic; few very Content of rock fragments: 5 to 35 percent fine and fine roots; few very fine and fine pores; pebbles 5 percent pebbles; disseminated lime; few fine Reaction: pH 7.4 to 8.4 masses of lime; strongly effervescent; moderately alkaline; gradual wavy boundary. BC—30 to 60 inches; very pale brown (10YR 7/3) 58B—Coben loam, 0 to 4 percent slopes gravelly clay loam, brown (10YR 5/3) moist; massive; slightly hard, firm, slightly sticky, slightly Setting plastic; few very fine and fine roots; few very fine Landform: Alluvial fans and stream terraces and fine pores; 20 percent pebbles; common faint Slope: 0 to 4 percent lime casts on underside of coarse fragments; Elevation: 4,000 to 5,200 feet strongly effervescent; moderately alkaline. Mean annual precipitation: 15 to 19 inches Range in Characteristics Frost-free period: 70 to 90 days Soil temperature: 38 to 43 degrees F Composition Moisture control section: Between depths of 4 to Major Components 12 inches Coben and similar soils: 85 percent Depth to lime: 12 to 30 inches Depth to the Bt horizon: 4 to 7 inches Minor Components Soils that have slopes more than 4 percent: 0 to Ap horizons 5 percent Hue: 10YR or 2.5Y Coben cobbly loam: 0 to 5 percent Value: 4 or 5 dry; 2 or 3 moist Soils that have high lime subsoils: 0 to 5 percent Chroma: 2 or 3 Clay content: 20 to 27 percent Major Component Description Content of rock fragments: 0 to 15 percent Surface layer texture: Loam pebbles Depth class: Very deep (more than 60 inches) Reaction: pH 6.1 to 7.3 Drainage class: Well drained Bt horizons Dominant parent material: Alluvium Hue: 10YR or 2.5Y Native plant cover type: Rangeland Value: 4 or 5 dry; 3 or 4 moist Flooding: None Chroma: 2 to 4 Available water capacity: Mainly 8.5 inches Texture: Clay, silty clay, or clay loam Clay content: 35 to 60 percent A typical soil description with range in Content of rock fragments: 0 to 10 percent characteristics is included, in alphabetical order, in pebbles this section. Powell County Area, Montana—Part I 75
Management Composition For management information about this map unit, Major Components see appropriate sections in Part II of this publication. Coben and similar soils: 85 percent Minor Components Soils that have slopes more than 15 percent: 0 to 58C—Coben loam, 4 to 8 percent slopes 5 percent Coben cobbly loam: 0 to 5 percent Setting Soils that have high lime subsoils: 0 to 5 percent Landform: Alluvial fans and stream terraces Major Component Description Slope: 4 to 8 percent Surface layer texture: Loam Elevation: 4,000 to 5,200 feet Depth class: Very deep (more than 60 inches) Mean annual precipitation: 15 to 19 inches Drainage class: Well drained Frost-free period: 70 to 90 days Dominant parent material: Alluvium Composition Native plant cover type: Rangeland Flooding: None Major Components Available water capacity: Mainly 8.5 inches Coben and similar soils: 85 percent Minor Components A typical soil description with range in Soils that have slopes more than 8 percent: 0 to characteristics is included, in alphabetical order, in 5 percent this section. Coben cobbly loam: 0 to 5 percent Management Soils that have high lime subsoils: 0 to 5 percent For management information about this map unit, Major Component Description see appropriate sections in Part II of this publication. Surface layer texture: Loam Depth class: Very deep (more than 60 inches) Drainage class: Well drained Comad Series Dominant parent material: Alluvium Depth class: Very deep Native plant cover type: Rangeland Drainage class: Excessively drained Flooding: None Permeability: Rapid Available water capacity: Mainly 8.5 inches Landform: Mountains Parent material: Granitic colluvium A typical soil description with range in Slope range: 8 to 60 percent characteristics is included, in alphabetical order, in Elevation range: 4,600 to 7,500 feet this section. Annual precipitation: 20 to 30 inches Management Annual air temperature: 35 to 38 degrees F Frost-free period: 30 to 70 days For management information about this map unit, see appropriate sections in Part II of this publication. Taxonomic Class: Sandy-skeletal, mixed Lamellic Cryorthents 58D—Coben loam, 8 to 15 percent slopes Typical Pedon Comad very stony sandy loam, in an area of Comad- Setting Elkner complex, 35 to 60 percent slopes, in an area of woodland, 2,800 feet south and 1,650 feet east of Landform: Alluvial fans and stream terraces the northwest corner of sec. 29, T. 11 N., R. 7 W. Slope: 8 to 15 percent Elevation: 4,000 to 5,200 feet Oi—1 inch to 0; partially decomposed forest litter. Mean annual precipitation: 15 to 19 inches E1—0 to 4 inches; light brownish gray (10YR 6/2) Frost-free period: 70 to 90 days very stony sandy loam, very dark grayish brown 76 Soil Survey
(10YR 3/2) moist; weak fine granular structure; Content of rock fragments: 35 to 80 percent— soft, very friable, nonsticky, nonplastic; few fine 10 to 35 percent boulders and stones; 15 to and medium roots; few medium discontinuous 25 percent cobbles; 10 to 20 percent pebbles irregular pores; 25 percent stones, 20 percent Reaction: pH 5.1 to 7.3 cobbles, and 10 percent pebbles; moderately E and Bt1 horizon acid; clear wavy boundary. Hue: 7.5YR or 10YR E2—4 to 17 inches; light brownish gray (10YR 6/2) Value: E part—6 or 7 dry, 4 to 6 moist; B part— very stony loamy sand, very dark grayish brown 5 or 6 dry, 4 or 5 moist (10YR 3/2) moist; weak fine subangular blocky Chroma: E part—2 or 3; B part—3, 4, or 6 structure; soft, very friable, nonsticky, nonplastic; Texture: Sand, coarse sand, or loamy sand; the few medium roots; few medium discontinuous lamellae are sandy loam or sandy clay loam irregular pores; 25 percent stones, 20 percent Clay content: 0 to 10 percent cobbles, and 10 percent pebbles; moderately Content of rock fragments: 40 to 80 percent— acid; gradual wavy boundary. 15 to 35 percent stones; 15 to 25 percent E and Bt—17 to 42 inches; 80 percent is light cobbles; 10 to 20 percent pebbles brownish gray (10YR 6/2) extremely stony loamy Reaction: pH 5.1 to 7.3 sand, grayish brown (10YR 5/2) moist (E part); 20 percent is brownish yellow (10YR 6/6) sandy C horizon 1 1 clay loam lamellae /4- to /2-inch thick, yellowish Hue: 7.5YR or 10YR brown (10YR 5/6) moist (B part); weak medium Value: 6 or 7 dry; 4 or 5 moist subangular blocky structure; soft, very friable, Chroma: 2 or 3 nonsticky, nonplastic; few very fine roots; few Texture: Sand or loamy sand medium discontinuous irregular pores; 25 percent Clay content: 0 to 10 percent stones, 15 percent cobbles, and 20 percent Content of rock fragments: 40 to 80 percent— pebbles; slightly acid; diffuse wavy boundary. 15 to 35 percent stones; 15 to 25 percent C—42 to 60 inches; light brownish gray (10YR 6/2) cobbles; 10 to 20 percent pebbles extremely stony loamy sand, dark grayish brown Reaction: pH 5.1 to 7.3 (10YR 4/2) moist; massive; loose, nonsticky, nonplastic; few very fine roots; 25 percent stones, 15 percent cobbles, and 20 percent pebbles; 280E—Comad-Elkner-Rock outcrop neutral. complex, 15 to 35 percent slopes
Range in Characteristics Setting Landform: Soil temperature: 36 to 43 degrees F • Comad—Mountains Moisture control section: Between depths of 12 and • Elkner—Mountains 35 inches • Rock outcrop—Mountains Depth to lamellae: 13 to 20 inches Slope: Soil phases: Bouldery • Comad—15 to 35 percent E1 horizon • Elkner—15 to 35 percent Hue: 7.5YR or 10YR Elevation: 4,600 to 7,500 feet Value: 6 or 7 dry; 3 to 5 moist Mean annual precipitation: 20 to 30 inches Chroma: 2 or 3 Frost-free period: 30 to 70 days Clay content: 5 to 15 percent Composition Content of rock fragments: 35 to 85 percent—5 to 35 percent boulders and stones; 20 to Major Components 30 percent cobbles; 10 to 15 percent pebbles Comad and similar soils: 40 percent Reaction: pH 5.1 to 7.3 Elkner and similar soils: 25 percent Rock outcrop: 20 percent E2 horizon Hue: 7.5YR or 10YR Minor Components Value: 6 to 8 dry; 3 to 6 moist Soils that are less than 40-inches deep: 0 to Chroma: 2 or 3 8 percent Clay content: 5 to 15 percent Areas of rubble land: 0 to 7 percent Powell County Area, Montana—Part I 77
Major Component Description Minor Components Soils that are less than 40-inches deep: 0 to Comad 8 percent Surface layer texture: Extremely bouldery sandy loam Areas of rubble land: 0 to 7 percent Depth class: Very deep (more than 60 inches) Drainage class: Excessively drained Major Component Description Dominant parent material: Colluvium Native plant cover type: Forestland Comad Flooding: None Surface layer texture: Extremely bouldery sandy loam Available water capacity: Mainly 1.4 inches Depth class: Very deep (more than 60 inches) Drainage class: Excessively drained Elkner Dominant parent material: Colluvium Surface layer texture: Bouldery sandy loam Native plant cover type: Forestland Depth class: Very deep (more than 60 inches) Flooding: None Drainage class: Somewhat excessively drained Available water capacity: Mainly 1.4 inches Dominant parent material: Colluvium Native plant cover type: Forestland Elkner Flooding: None Surface layer texture: Bouldery sandy loam Available water capacity: Mainly 5.6 inches Depth class: Very deep (more than 60 inches) Drainage class: Somewhat excessively drained Rock outcrop Dominant parent material: Colluvium Definition: Areas of exposed bedrock Native plant cover type: Forestland Flooding: None A typical soil description with range in Available water capacity: Mainly 5.6 inches characteristics is included, in alphabetical order, in this section. Rock outcrop Management Definition: Areas of exposed bedrock For management information about this map unit, A typical soil description with range in see appropriate sections in Part II of this publication. characteristics is included, in alphabetical order, in this section. 280F—Comad-Elkner-Rock outcrop Management complex, 35 to 60 percent slopes For management information about this map unit, see appropriate sections in Part II of this publication. Setting Landform: • Comad—Mountains 580E—Comad-Elkner complex, • Elkner—Mountains 15 to 35 percent slopes • Rock outcrop—Mountains Slope: • Comad—35 to 60 percent Setting • Elkner—35 to 60 percent Elevation: 4,600 to 7,500 feet Landform: Mean annual precipitation: 20 to 30 inches • Comad—Mountains Frost-free period: 30 to 70 days • Elkner—Mountains Slope: Composition • Comad—15 to 35 percent Major Components • Elkner—15 to 35 percent Comad and similar soils: 40 percent Elevation: 4,600 to 7,500 feet Elkner and similar soils: 25 percent Mean annual precipitation: 20 to 30 inches Rock outcrop: 20 percent Frost-free period: 30 to 70 days 78 Soil Survey
Composition Composition Major Components Major Components Comad and similar soils: 65 percent Comad and similar soils: 65 percent Elkner and similar soils: 20 percent Elkner and similar soils: 20 percent Minor Components Minor Components Soils that have slopes more than 35 percent: 0 to Soils that have slopes more than 60 percent: 0 to 5 percent 5 percent Areas of rock outcrop: 0 to 5 percent Areas of rock outcrop: 0 to 5 percent Soils that are moderately deep: 0 to 5 percent Soils that are moderately deep: 0 to 5 percent Major Component Description Major Component Description Comad Surface layer texture: Very stony sandy loam Comad Depth class: Very deep (more than 60 inches) Surface layer texture: Very stony sandy loam Drainage class: Excessively drained Depth class: Very deep (more than 60 inches) Dominant parent material: Colluvium Drainage class: Excessively drained Native plant cover type: Forestland Dominant parent material: Colluvium Flooding: None Native plant cover type: Forestland Available water capacity: Mainly 1.4 inches Flooding: None Available water capacity: Mainly 1.4 inches Elkner Surface layer texture: Stony sandy loam Elkner Depth class: Very deep (more than 60 inches) Surface layer texture: Stony sandy loam Drainage class: Somewhat excessively drained Depth class: Very deep (more than 60 inches) Dominant parent material: Colluvium Drainage class: Somewhat excessively drained Native plant cover type: Forestland Dominant parent material: Colluvium Flooding: None Native plant cover type: Forestland Available water capacity: Mainly 4.4 inches Flooding: None Available water capacity: Mainly 4.4 inches A typical soil description with range in characteristics is included, in alphabetical order, in A typical soil description with range in this section. characteristics is included, in alphabetical order, in this section. Management Management For management information about this map unit, see appropriate sections in Part II of this publication. For management information about this map unit, see appropriate sections in Part II of this publication. 580F—Comad-Elkner complex, 35 to 60 percent slopes 680F—Comad-Rubble land complex, 35 to 60 percent slopes Setting Landform: Setting • Comad—Mountains • Elkner—Mountains Landform: Slope: • Comad—Mountains • Comad—35 to 60 percent • Rubble land—Mountains • Elkner—35 to 60 percent Slope: 35 to 60 percent Elevation: 4,600 to 7,500 feet Elevation: 4,600 to 7,500 feet Mean annual precipitation: 20 to 30 inches Mean annual precipitation: 20 to 30 inches Frost-free period: 30 to 70 days Frost-free period: 30 to 70 days Powell County Area, Montana—Part I 79
Composition Typical Pedon Major Components Con loam, 0 to 4 percent slopes, in an area of Comad and similar soils: 65 percent cropland, 300 feet north and 600 feet east of the Rubble land: 20 percent southwest corner of sec. 24, T. 7 N., R. 10 W. Minor Components Ap—0 to 7 inches; brown (10YR 5/3) loam, dark Soils that have a cobbly sandy loam subsoil: 0 to brown (10YR 3/3) moist; weak medium granular 5 percent structure; soft; friable, nonsticky, nonplastic; Soils that have slopes more than 60 percent: 0 to common very fine and fine roots; 5 percent 5 percent pebbles; neutral; clear smooth boundary. Areas of rock outcrop: 0 to 5 percent Bw—7 to 11 inches; yellowish brown (10YR 5/4) clay loam, dark brown (10YR 4/3) moist; moderate Major Component Description medium subangular blocky structure; slightly Comad hard, friable, moderately sticky, slightly plastic; Surface layer texture: Extremely bouldery sandy loam common very fine and fine roots; many fine Depth class: Very deep (more than 60 inches) irregular pores; 5 percent pebbles; slightly Drainage class: Excessively drained alkaline; clear smooth boundary. Dominant parent material: Colluvium Bk1—11 to 21 inches; white (10YR 8/2) loam, very Native plant cover type: Forestland pale brown (10YR 7/4) moist; weak fine Flooding: None subangular blocky structure; slightly hard, friable, Available water capacity: Mainly 1.4 inches slightly sticky, slightly plastic; few very fine and fine roots; many fine irregular pores; continuous Rubble land distinct lime coatings and casts on surface of Definition: Areas having more than 90 percent pebbles; common fine masses of lime; violently boulders, stones, and cobbles on the surface, effervescent; 5 percent pebbles; moderately supporting little or no vegetation alkaline; clear wavy boundary. Bk2—21 to 34 inches; very pale brown (10YR 7/3) A typical soil description with range in loam, brown (10YR 5/3) moist; weak fine characteristics is included, in alphabetical order, in subangular blocky structure; soft, friable, slightly this section. sticky, nonplastic; few very fine and fine roots; common fine irregular pores; 5 percent pebbles; Management continuous distinct lime casts and coatings on For management information about this map unit, surface of pebbles; common fine masses of lime; see appropriate sections in Part II of this publication. violently effervescent; moderately alkaline; clear wavy boundary. Bk3—34 to 60 inches; very pale brown (10YR 7/3) Con Series gravelly loam, pale brown (10YR 6/3) moist; weak fine subangular blocky structure; soft, friable, Depth class: Very deep nonsticky, nonplastic; few very fine and fine roots; Drainage class: Well drained common fine irregular pores; 15 percent pebbles; Permeability: Moderate continuous distinct lime casts and coatings on Landform: Alluvial fans and stream terraces surface of pebbles; common fine masses of lime; Parent material: Calcareous alluvium violently effervescent; moderately alkaline. Slope range: 0 to 60 percent Range in Characteristics Elevation range: 4,000 to 5,800 feet Annual precipitation: 10 to 14 inches Soil temperature: 41 to 46 degrees F Annual air temperature: 39 to 44 degrees F Moisture control section: Between depths of 4 and Frost-free period: 90 to 105 days 12 inches; dry in some part for six-tenths or more of the cumulative days per year when Taxonomic Class: Fine-loamy, mixed, superactive, the soil temperature at a depth of 20 inches is frigid Aridic Haplustolls 41 degrees F or higher 80 Soil Survey
Thickness of the mollic epipedon: 7 to 10 inches Mean annual precipitation: 10 to 14 inches Depth to the calcic horizon: 11 to 18 inches Frost-free period: 90 to 105 days Ap horizon Composition Chroma: 1 to 3 Major Components Clay content: 18 to 27 percent Con and similar soils: 85 percent Content of rock fragments: 0 to 35 percent—0 to 20 percent cobbles; 0 to 15 percent pebbles Minor Components Reaction: pH 4.5 to 7.3 Con very gravelly loam: 0 to 10 percent Soils that are somewhat poorly drained: 0 to Bw horizon 5 percent Value: 4 to 6 dry; 4, or 5 moist Chroma: 3 or 4 Major Component Description Texture: Loam or clay loam Clay content: 18 to 35 percent Surface layer texture: Loam Content of rock fragments: 0 to 15 percent Depth class: Very deep (more than 60 inches) pebbles Drainage class: Well drained Reaction: pH 6.6 to 7.8 Dominant parent material: Alluvium Native plant cover type: Rangeland Bk1 horizon Flooding: None Value: 7 or 8 dry; 5 to 7 moist Available water capacity: Mainly 8.8 inches Chroma: 2 to 4 Texture: Loam, clay loam, or sandy loam A typical soil description with range in Clay content: 18 to 35 percent characteristics is included, in alphabetical order, in Content of rock fragments: 0 to 20 percent—0 to this section. 5 percent cobbles; 0 to 15 percent pebbles Calcium carbonate equivalent: 15 to 40 percent Management Reaction: pH 7.9 to 8.4 For management information about this map unit, Bk2 horizon see appropriate sections in Part II of this publication. Value: 5 to 8 dry; 4 to 6 moist Chroma: 3 or 4 Texture: Sandy loam, clay loam, or loam 24C—Con loam, 4 to 8 percent slopes Clay content: 18 to 35 percent Content of rock fragments: 0 to 25 percent—0 to Setting 5 percent cobbles; 0 to 20 percent pebbles Calcium carbonate equivalent: 15 to 25 percent Landform: Alluvial fans and stream terraces Reaction: pH 7.9 to 8.4 Slope: 4 to 8 percent Elevation: 4,000 to 5,000 feet Bk3 horizon Mean annual precipitation: 10 to 14 inches Value: 5 to 8 dry; 4 or 6 moist Frost-free period: 90 to 105 days Chroma: 3 or 4 Texture: Sandy loam or loam Composition Clay content: 18 to 27 percent Major Components Content of rock fragments: 0 to 25 percent—0 to Con and similar soils: 85 percent 5 percent cobbles; 0 to 20 percent pebbles Calcium carbonate equivalent: 15 to 25 percent Minor Components Reaction: pH 7.9 to 8.4 Con very gravelly loam: 0 to 10 percent Soils that are somewhat poorly drained: 0 to 5 percent 24B—Con loam, 0 to 4 percent slopes Major Component Description Surface layer texture: Loam Setting Depth class: Very deep (more than 60 inches) Landform: Alluvial fans and stream terraces Drainage class: Well drained Slope: 0 to 4 percent Dominant parent material: Alluvium Elevation: 4,000 to 5,000 feet Native plant cover type: Rangeland Powell County Area, Montana—Part I 81
Flooding: None Slope: Available water capacity: Mainly 8.8 inches • Con—15 to 35 percent • Sixbeacon—15 to 35 percent A typical soil description with range in Elevation: 4,000 to 5,000 feet characteristics is included, in alphabetical order, in Mean annual precipitation: 10 to 14 inches this section. Frost-free period: 90 to 105 days Management Composition For management information about this map unit, Major Components see appropriate sections in Part II of this publication. Con and similar soils: 55 percent Sixbeacon and similar soils: 30 percent 24D—Con loam, 8 to 15 percent slopes Minor Components Con, calcareous surface: 0 to 5 percent Soils that have slopes more than 35 percent: 0 to Setting 5 percent Landform: Alluvial fans and stream terraces Soils that have a gravelly clay loam subsoil: 0 to Slope: 8 to 15 percent 5 percent Elevation: 4,000 to 5,000 feet Major Component Description Mean annual precipitation: 10 to 14 inches Frost-free period: 90 to 105 days Con Surface layer texture: Cobbly loam Composition Depth class: Very deep (more than 60 inches) Major Components Drainage class: Well drained Con and similar soils: 85 percent Dominant parent material: Alluvium Native plant cover type: Rangeland Minor Components Flooding: None Con very gravelly loam: 0 to 15 percent Available water capacity: Mainly 8.5 inches Major Component Description Sixbeacon Surface layer texture: Loam Surface layer texture: Cobbly loam Depth class: Very deep (more than 60 inches) Depth class: Very deep (more than 60 inches) Drainage class: Well drained Drainage class: Well drained Dominant parent material: Alluvium Dominant parent material: Alluvium Native plant cover type: Rangeland Native plant cover type: Rangeland Flooding: None Flooding: None Available water capacity: Mainly 8.8 inches Available water capacity: Mainly 7.4 inches A typical soil description with range in A typical soil description with range in characteristics is included, in alphabetical order, in characteristics is included, in alphabetical order, in this section. this section. Management Management For management information about this map unit, For management information about this map unit, see appropriate sections in Part II of this publication. see appropriate sections in Part II of this publication.
824E—Con-Sixbeacon cobbly loams, 824F—Con-Sixbeacon cobbly loams, 15 to 35 percent slopes 35 to 60 percent slopes
Setting Setting Landform: Landform: • Con—Alluvial fans and stream terraces • Con—Alluvial fans and stream terraces • Sixbeacon—Alluvial fans • Sixbeacon—Alluvial fans 82 Soil Survey
Slope: Elevation range: 5,000 to 8,600 feet • Con—35 to 60 percent Annual precipitation: 18 to 22 inches • Sixbeacon—35 to 60 percent Annual air temperature: 34 to 39 degrees F Elevation: 4,000 to 5,000 feet Frost-free period: 30 to 70 days Mean annual precipitation: 10 to 14 inches Frost-free period: 90 to 105 days Taxonomic Class: Loamy-skeletal, mixed, superactive Lithic Argicryolls Composition Typical Pedon Major Components Con and similar soils: 55 percent Copenhaver gravelly loam, in an area of Libeg- Sixbeacon and similar soils: 30 percent Monad-Copenhaver complex, 8 to 15 percent slopes, in an area of rangeland, 350 feet south and 250 feet Minor Components east of the northwest corner of sec. 15, T. 8 N., Con, calcareous surface: 0 to 8 percent R. 8 W. Soils that have a gravelly clay loam subsoil: 0 to 7 percent A—0 to 5 inches; dark grayish brown (10YR 4/2) gravelly loam, very dark brown (10YR 2/2) moist; Major Component Description moderate fine granular structure; soft, very Con friable, nonsticky, nonplastic; many very fine and Surface layer texture: Cobbly loam fine roots; many very fine pores; 25 percent Depth class: Very deep (more than 60 inches) pebbles; neutral; clear smooth boundary. Drainage class: Well drained Bt—5 to 14 inches; reddish brown (5YR 5/3) very Dominant parent material: Alluvium gravelly clay loam, dark reddish brown (5YR 3/3) Native plant cover type: Rangeland moist; weak fine subangular blocky structure; Flooding: None very hard, friable, slightly sticky, moderately Available water capacity: Mainly 8.5 inches plastic; many very fine and fine roots; many very fine and fine pores; few faint clay films on faces of Sixbeacon peds and on coarse fragments; 10 percent Surface layer texture: Cobbly loam cobbles and 40 percent pebbles; slightly alkaline. Depth class: Very deep (more than 60 inches) R—14 inches; andesite bedrock. Drainage class: Well drained Dominant parent material: Alluvium Range in Characteristics Native plant cover type: Rangeland Soil temperature: 36 to 41 degrees F Flooding: None Moisture control section: Between depths of 4 and Available water capacity: Mainly 7.4 inches 12 inches Depth to bedrock: 10 to 20 inches A typical soil description with range in characteristics is included, in alphabetical order, in A horizon this section. Hue: 10YR, 7.5YR, or 5YR Value: 3 or 4 dry; 2 or 3 moist Management Chroma: 2 or 3 For management information about this map unit, Clay content: 18 to 27 percent see appropriate sections in Part II of this publication. Content of rock fragments: 15 to 35 percent—0 to 5 percent cobbles; 15 to 30 percent pebbles Reaction: pH 6.6 to 7.3 Copenhaver Series Bt horizon Depth class: Shallow Hue: 5YR or 7.5YR Drainage class: Well drained Value: 4 or 5 dry; 3 or 4 moist Permeability: Moderately slow Chroma: 2 to 4 or 6 Landform: Hills and mountains Clay content: 27 to 35 percent Parent material: Material derived from andesite and Content of rock fragments: 35 to 80 percent—5 to basalt 20 percent cobbles; 30 to 60 percent pebbles Slope range: 8 to 60 percent Reaction: pH 7.4 to 7.8 Powell County Area, Montana—Part I 83
Crackerville Series common faint clay films on faces of peds and on pebbles; 10 percent cobbles and 40 percent Depth class: Moderately deep pebbles; slightly alkaline; clear smooth boundary. Drainage class: Well drained Cr—23 to 32 inches; yellowish brown (10YR 5/4) Permeability: Moderately slow semiconsolidated bedrock. Landform: Mountains R—32 inches; granite bedrock. Parent material: Granitic residuum and colluvium Range in Characteristics Slope range: 4 to 35 percent Elevation range: 3,500 to 5,200 feet Soil temperature: 40 to 44 degrees F Annual precipitation: 15 to 19 inches Moisture control section: Between depths of 4 and Annual air temperature: 39 to 44 degrees F 12 inches Frost-free period: 70 to 90 days Thickness of the mollic epipedon: 7 to 15 inches Depth to the argillic horizon: 7 to 15 inches Taxonomic Class: Loamy-skeletal, mixed, Depth to the Cr horizon: 20 to 38 inches superactive, frigid Typic Argiustolls Depth to bedrock: 23 to 40 inches A horizons Typical Pedon Hue: 10YR or 2.5Y Value: 4 or 5 dry; 2 or 3 moist Crackerville loam, in an area of Clasoil-Crackerville Chroma: 2 or 3 complex, 8 to 15 percent slopes, in an area of Clay content: 14 to 22 percent rangeland, 400 feet north and 2,400 feet east of the Content of rock fragments: 5 to 15 percent—0 to southwest corner of sec. 5, T. 6 N., R. 8 W. 5 percent cobbles; 5 to 10 percent pebbles A1—0 to 5 inches; dark grayish brown (10YR 4/2) (pebbles are mainly less than 7 mm in loam, very dark brown (10YR 2/2) moist; weak diameter) fine subangular blocky structure; soft, friable, Reaction: pH 5.1 to 7.3 nonsticky, slightly plastic; many very fine and fine Bt horizons roots; many very fine continuous interstitial pores; Hue: 10YR or 2.5Y 5 percent cobbles and 5 percent pebbles; Value: 5 or 6 dry; 3 or 4 moist strongly acid; clear smooth boundary. Chroma: 3, 4, or 6 dry A2—5 to 8 inches; brown (10YR 4/3) sandy loam, Texture: Sandy clay loam or coarse sandy clay very dark brown (10YR 2/2) moist; moderate very loam fine and fine subangular blocky structure; slightly Clay content: 20 to 30 percent hard, friable, nonsticky, slightly plastic; many very Content of rock fragments: 35 to 60 percent—0 to fine and common fine roots; many very fine 15 percent cobbles; 35 to 45 percent pebbles discontinuous interstitial pores; 5 percent cobbles (pebbles are mainly less than 7 mm in and 5 percent pebbles; neutral; clear smooth diameter) boundary. Reaction: pH 6.6 to 7.8 Bt1—8 to 14 inches; brown (10YR 5/3) very gravelly sandy clay loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; Crow Series hard, friable, slightly sticky, slightly plastic; common very fine and fine roots; common very Depth class: Very deep fine discontinuous interstitial pores; common Drainage class: Well drained faint clay films on faces of peds and on pebbles; Permeability: Slow 5 percent cobbles and 35 percent pebbles; Landform: Mountains, moraines, and hills slightly alkaline; clear smooth boundary. Parent material: Colluvium derived from fine-grained Bt2—14 to 23 inches; yellowish brown (10YR 5/4) extrusive igneous rocks and alpine till very gravelly sandy clay loam, dark yellowish Slope range: 4 to 50 percent brown (10YR 3/4) moist; moderate medium Elevation range: 4,000 to 5,800 feet subangular blocky structure; hard, friable, slightly Annual precipitation: 18 to 30 inches sticky, slightly plastic; few very fine and fine roots; Annual air temperature: 38 to 42 degrees F few very fine discontinuous interstitial pores; Frost-free period: 70 to 90 days 84 Soil Survey
Taxonomic Class: Fine, mixed, superactive, frigid E horizon Typic Haplustalfs Value: 5 to 7 dry; 4 or 5 moist Chroma: 2 or 3 Typical Pedon Texture: Loam or clay loam Crow loam, in an area of Crow-Bignell complex, 15 to Clay content: 10 to 35 percent 35 percent slopes, in an area of woodland, 2,300 feet Content of rock fragments: 0 to 15 percent—0 to south and 1,500 feet west of the northeast corner of 5 percent cobbles; 0 to 10 percent pebbles sec. 9, T. 12 N., R. 9 W. Reaction: pH 5.6 to 6.5 E—0 to 3 inches; grayish brown (10YR 5/2) loam, Bt/E horizon dark grayish brown (10YR 4/2) moist; weak Hue: 10YR or 2.5Y medium granular structure; soft, friable, slightly Value: B part—5 or 6 dry, 4 or 5 moist; E part— sticky, slightly plastic; many very fine, fine, 6 to 8 dry, 5 or 6 moist medium, and coarse roots; many very fine and Chroma: B part—2 to 4; E part—2 or 3 fine discontinuous irregular pores; slightly acid; Texture, mixed: Silty clay loam, clay loam, loam, clear smooth boundary. or silt loam Bt/E—3 to 7 inches; 60 percent is brown (10YR 5/3) Clay content, mixed: 20 to 40 percent clay, dark brown (10YR 4/3) moist (B part); Content of rock fragments: 0 to 25 percent—0 to 40 percent is light brownish gray (10YR 6/2) silt 5 percent cobbles; 0 to 20 percent pebbles loam, grayish brown (10YR 5/2) moist tongues Reaction: pH 5.6 to 6.5 (E part); moderate medium subangular blocky Bt horizons structure; slightly hard, friable, slightly sticky, Hue: 10YR or 2.5Y slightly plastic; many very fine, fine, medium, and Value: 4 to 6 dry; 4 or 5 moist coarse roots; many very fine and fine Chroma: 2 to 4 discontinuous irregular pores; slightly acid; clear Texture: Silty clay, clay, sandy clay, or clay loam smooth boundary. Clay content: 35 to 60 percent Bt1—7 to 17 inches; brown (10YR 5/3) clay, dark Content of rock fragments: 0 to 35 percent—0 to brown (10YR 4/3) moist; strong medium 10 percent cobbles; 0 to 25 percent pebbles subangular blocky structure; hard, firm, Reaction: pH 6.1 to 7.3 moderately sticky, moderately plastic; many very fine and fine roots; common very fine and fine BC horizon discontinuous irregular pores; many prominent Hue: 2.5Y, 10YR, or 7.5YR clay films on faces of peds; neutral; clear wavy Value: 6 or 7 dry; 4 to 6 moist boundary. Chroma: 2 to 4 Bt2—17 to 31 inches; yellowish brown (10YR 5/4) Texture: Sandy clay loam, clay loam, or loam clay, dark yellowish brown (10YR 4/4) moist; Clay content: 20 to 35 percent moderate medium subangular blocky structure; Content of rock fragments: 5 to 35 percent—0 to hard, firm, slightly sticky, moderately plastic; few 10 percent cobbles; 5 to 25 percent pebbles very fine and fine roots; common very fine and Reaction: pH 6.1 to 7.8 fine discontinuous irregular pores; many prominent clay films on faces of peds; 5 percent cobbles and 10 percent pebbles; neutral; clear 83D—Crow clay loam, wavy boundary. 4 to 15 percent slopes BC—31 to 60 inches; light yellowish brown (10YR 6/4) sandy clay loam, yellowish brown (10YR 5/4) Setting moist; massive; hard, firm, slightly sticky, moderately plastic; few very fine and fine roots; Landform: Mountains few very fine and fine discontinuous irregular Slope: 4 to 15 percent pores; few faint clay bridges; 5 percent cobbles Elevation: 4,000 to 5,800 feet and 10 percent pebbles; neutral. Mean annual precipitation: 18 to 24 inches Frost-free period: 70 to 90 days Range in Characteristics Composition Soil temperature: 40 to 47 degrees F Moisture control section: Between depths of 4 and Major Components 12 inches Crow and similar soils: 85 percent Powell County Area, Montana—Part I 85
Minor Components Management Soils that have slopes more than 15 percent: 0 to For management information about this map unit, 15 percent see appropriate sections in Part II of this publication. Major Component Description Surface layer texture: Clay loam 283D—Crow clay loam, moist, Depth class: Very deep (more than 60 inches) 4 to 15 percent slopes Drainage class: Well drained Dominant parent material: Colluvium Setting Native plant cover type: Forestland Flooding: None Landform: Moraines Available water capacity: Mainly 9.1 inches Slope: 4 to 15 percent Elevation: 4,000 to 5,800 feet A typical soil description with range in Mean annual precipitation: 24 to 30 inches characteristics is included, in alphabetical order, in Frost-free period: 70 to 90 days this section. Composition Management Major Components For management information about this map unit, Crow and similar soils: 85 percent see appropriate sections in Part II of this publication. Minor Components Bignell soils: 0 to 5 percent 83E—Crow clay loam, Poorly drained soils: 0 to 5 percent 15 to 35 percent slopes Soils that are calcareous throughout: 0 to 5 percent Major Component Description Setting Surface layer texture: Clay loam Landform: Mountains Depth class: Very deep (more than 60 inches) Slope: 15 to 35 percent Drainage class: Well drained Elevation: 4,000 to 5,800 feet Dominant parent material: Alpine till Mean annual precipitation: 18 to 24 inches Native plant cover type: Forestland Frost-free period: 70 to 90 days Flooding: None Available water capacity: Mainly 9.1 inches Composition Major Components A typical soil description with range in Crow and similar soils: 85 percent characteristics is included, in alphabetical order, in this section. Minor Components Soils that have slopes more than 35 percent: 0 to Management 15 percent For management information about this map unit, Major Component Description see appropriate sections in Part II of this publication. Surface layer texture: Clay loam Depth class: Very deep (more than 60 inches) 283E—Crow clay loam, moist, Drainage class: Well drained 15 to 35 percent slopes Dominant parent material: Colluvium Native plant cover type: Forestland Setting Flooding: None Available water capacity: Mainly 9.1 inches Landform: Moraines Slope: 8 to 15 percent A typical soil description with range in Elevation: 4,000 to 5,800 feet characteristics is included, in alphabetical order, in Mean annual precipitation: 24 to 30 inches this section. Frost-free period: 70 to 90 days 86 Soil Survey
Composition Depth class: Very deep (more than 60 inches) Drainage class: Well drained Major Components Dominant parent material: Alpine till Crow and similar soils: 85 percent Native plant cover type: Forestland Minor Components Flooding: None Bignell soils: 0 to 5 percent Available water capacity: Mainly 9.0 inches Soils that are calcareous throughout: 0 to 5 percent Areas of rock outcrop: 0 to 5 percent Bignell Surface layer texture: Gravelly clay loam Major Component Description Depth class: Very deep (more than 60 inches) Surface layer texture: Clay loam Drainage class: Well drained Depth class: Very deep (more than 60 inches) Dominant parent material: Alpine till Drainage class: Well drained Native plant cover type: Forestland Dominant parent material: Alpine till Flooding: None Native plant cover type: Forestland Available water capacity: Mainly 5.3 inches Flooding: None Available water capacity: Mainly 9.1 inches A typical soil description with range in characteristics is included, in alphabetical order, in A typical soil description with range in this section. characteristics is included, in alphabetical order, in Management this section. For management information about this map unit, Management see appropriate sections in Part II of this publication. For management information about this map unit, see appropriate sections in Part II of this publication. 883F—Crow-Bignell complex, moist, 25 to 50 percent slopes 883E—Crow-Bignell complex, moist, 8 to 25 percent slopes Setting Landform: Setting • Crow—Moraines Landform: • Bignell—Moraines • Crow—Moraines Slope: • Bignell—Moraines • Crow—25 to 50 percent Slope: • Bignell—25 to 50 percent • Crow—8 to 25 percent Elevation: 4,000 to 5,800 feet • Bignell—8 to 25 percent Mean annual precipitation: 24 to 30 inches Elevation: 4,000 to 5,800 feet Frost-free period: 70 to 90 days Mean annual precipitation: 24 to 30 inches Composition Frost-free period: 70 to 90 days Major Components Composition Crow and similar soils: 45 percent Major Components Bignell and similar soils: 40 percent Crow and similar soils: 45 percent Minor Components Bignell and similar soils: 40 percent Whitecow soils: 0 to 6 percent Minor Components Winkler soils: 0 to 6 percent Whitecow soils: 0 to 6 percent Poorly drained soils: 0 to 3 percent Winkler soils: 0 to 6 percent Major Component Description Poorly drained soils: 0 to 3 percent Crow Major Component Description Surface layer texture: Loam Crow Depth class: Very deep (more than 60 inches) Surface layer texture: Loam Drainage class: Well drained Powell County Area, Montana—Part I 87
Dominant parent material: Alpine till Drainage class: Well drained Native plant cover type: Forestland Dominant parent material: Colluvium Flooding: None Native plant cover type: Forestland Available water capacity: Mainly 9.0 inches Flooding: None Available water capacity: Mainly 9.0 inches Bignell Surface layer texture: Gravelly clay loam Bignell Depth class: Very deep (more than 60 inches) Surface layer texture: Gravelly clay loam Drainage class: Well drained Depth class: Very deep (more than 60 inches) Dominant parent material: Alpine till Drainage class: Well drained Native plant cover type: Forestland Dominant parent material: Colluvium Flooding: None Native plant cover type: Forestland Available water capacity: Mainly 5.3 inches Flooding: None Available water capacity: Mainly 5.5 inches A typical soil description with range in characteristics is included, in alphabetical order, in A typical soil description with range in this section. characteristics is included, in alphabetical order, in this section. Management Management For management information about this map unit, see appropriate sections in Part II of this publication. For management information about this map unit, see appropriate sections in Part II of this publication. 983D—Crow-Bignell complex, 8 to 15 percent slopes 983E—Crow-Bignell complex, 15 to 35 percent slopes Setting Landform: Setting • Crow—Mountains • Bignell—Mountains Landform: Slope: • Crow—Mountains • Crow—8 to 15 percent • Bignell—Mountains • Bignell—8 to 15 percent Slope: Elevation: 4,000 to 5,800 feet • Crow—15 to 35 percent Mean annual precipitation: 18 to 24 inches • Bignell—15 to 35 percent Frost-free period: 70 to 90 days Elevation: 4,000 to 5,800 feet Mean annual precipitation: 18 to 24 inches Composition Frost-free period: 70 to 90 days Major Components Crow and similar soils: 45 percent Composition Bignell and similar soils: 40 percent Major Components Minor Components Crow and similar soils: 45 percent Soils that have slopes more than 15 percent: 0 to Bignell and similar soils: 40 percent 4 percent Soils that are moderately deep: 0 to 4 percent Minor Components Poorly drained soils: 0 to 4 percent Soils that have slopes more than 35 percent: 0 to Trapps soils: 0 to 3 percent 3 percent Areas of rock outcrop: 0 to 3 percent Major Component Description Soils that are moderately deep: 0 to 3 percent Crow Trapps soils: 0 to 2 percent Surface layer texture: Loam Hoyt soils: 0 to 2 percent Depth class: Very deep (more than 60 inches) Poorly drained soils: 0 to 2 percent 88 Soil Survey
Major Component Description slightly sticky, slightly plastic; many fine and medium roots; many very fine and fine Crow continuous irregular pores; slightly acid; clear Surface layer texture: Loam wavy boundary. Depth class: Very deep (more than 60 inches) E/Bt—3 to 7 inches; 70 percent is light brownish gray Drainage class: Well drained (10YR 6/2) silt loam, dark brown (10YR 4/3) Dominant parent material: Colluvium moist tongues (E part); 30 percent is grayish Native plant cover type: Forestland brown (10YR 5/2) clay loam, brown (7.5YR 4/2) Flooding: None moist (B part); weak medium subangular blocky Available water capacity: Mainly 9.0 inches structure; slightly hard, friable, moderately sticky, moderately plastic; common fine and medium Bignell roots; common very fine and fine irregular pores; Surface layer texture: Gravelly clay loam 5 percent pebbles; slightly acid; gradual wavy Depth class: Very deep (more than 60 inches) boundary. Drainage class: Well drained Bt1—7 to 20 inches; brown (7.5YR 5/4) clay loam, Dominant parent material: Colluvium reddish brown (5YR 4/3) moist; moderate Native plant cover type: Forestland medium subangular blocky structure; hard, firm, Flooding: None moderately sticky, moderately plastic; common Available water capacity: Mainly 5.5 inches very fine roots; common very fine and fine irregular pores; many faint clay films on faces of A typical soil description with range in peds; 10 percent pebbles; moderately acid; characteristics is included, in alphabetical order, in gradual wavy boundary. this section. Bt2—20 to 38 inches; reddish brown (5YR 5/3) clay Management loam, strong brown (7.5YR 5/6) moist; moderate medium subangular blocky structure; hard, firm, For management information about this map unit, moderately sticky, moderately plastic; common see appropriate sections in Part II of this publication. very fine roots; few fine discontinuous tubular pores; continuous faint clay films on faces of peds; 10 percent pebbles; slightly acid; gradual Danaher Series wavy boundary. Bt3—38 to 60 inches; reddish brown (5YR 5/3) clay, Depth class: Very deep reddish brown (5YR 4/3) moist; moderate Drainage class: Well drained medium subangular blocky structure; very hard, Permeability: Slow very firm, moderately sticky, moderately plastic; Landform: Mountains few very fine roots; few fine discontinuous tubular Parent material: Material derived from igneous rock pores; few faint clay films on faces of peds; Slope range: 4 to 60 percent 10 percent pebbles; neutral. Elevation range: 5,000 to 8,000 feet Annual precipitation: 22 to 28 inches Range in Characteristics Annual air temperature: 35 to 38 degrees F Soil temperature: 37 to 42 degrees F Frost-free period: 30 to 70 days Moisture control section: Between depths of 4 and 12 inches Taxonomic Class: Fine, mixed, superactive Ustic Glossocryalfs E horizon Hue: 2.5YR, 5YR, 7.5YR, or 10YR Typical Pedon Value: 6 or 7 dry; 4 or 5 moist Danaher loam, in an area of Danaher-Loberg, Chroma: 2 or 3 complex, 15 to 35 percent slopes, in an area of Clay content: 18 to 27 percent woodland, 300 feet north and 650 feet east of the Content of rock fragments: 0 to 15 percent southwest corner of sec. 25, T. 11 N., R. 10 W. pebbles Reaction: pH 5.6 to 7.3 Oi—2.5 to 2 inches; undecomposed forest litter. Oe—2 inches to 0; decomposed forest litter. E/Bt horizon E—0 to 3 inches; light brownish gray (10YR 6/2) Hue: 2.5YR, 5YR, 7.5YR, or 10YR loam, dark brown (10YR 4/3) moist; moderate Value: E part—6 or 7 dry, 4 or 5 moist; B part— medium granular structure; slightly hard, friable, 4 or 5 dry, 3 or 4 moist Powell County Area, Montana—Part I 89
Chroma: 2 or 3 87E—Danaher loam, Texture: Silt loam, clay loam, or silty clay loam 15 to 35 percent slopes Clay content: 20 to 30 percent Content of rock fragments: 0 to 15 percent Setting pebbles Reaction: pH 5.6 to 7.3 Landform: Mountains Slope: 15 to 35 percent Bt horizons Elevation: 5,000 to 8,000 feet Hue: 2.5YR, 5YR, 7.5YR, or 10YR Mean annual precipitation: 22 to 28 inches Value: 5 or 6 dry; 4 or 5 moist Frost-free period: 30 to 70 days Chroma: 3, 4, or 6 Texture: Clay loam or clay Composition Clay content: 35 to 50 percent Content of rock fragments: 0 to 25 percent Major Components pebbles Danaher and similar soils: 85 percent Reaction: pH 5.6 to 7.3 Minor Components Poorly drained soils: 0 to 8 percent 87D—Danaher loam, Loberg soils: 0 to 7 percent 4 to 15 percent slopes Major Component Description Surface layer texture: Loam Setting Depth class: Very deep (more than 60 inches) Drainage class: Well drained Landform: Mountains Dominant parent material: Material weathered from Slope: 4 to 15 percent igneous rocks Elevation: 5,000 to 8,000 feet Native plant cover type: Forestland Mean annual precipitation: 22 to 28 inches Flooding: None Frost-free period: 30 to 70 days Available water capacity: Mainly 8.9 inches Composition A typical soil description with range in Major Components characteristics is included, in alphabetical order, in Danaher and similar soils: 85 percent this section. Minor Components Poorly drained soils: 0 to 8 percent Management Loberg soils: 0 to 7 percent For management information about this map unit, Major Component Description see appropriate sections in Part II of this publication. Surface layer texture: Loam Depth class: Very deep (more than 60 inches) Drainage class: Well drained 387E—Danaher-Loberg complex, Dominant parent material: Material weathered from 15 to 35 percent slopes igneous rocks Native plant cover type: Forestland Setting Flooding: None Available water capacity: Mainly 8.9 inches Landform: • Danaher—Mountains A typical soil description with range in • Loberg—Mountains characteristics is included, in alphabetical order, in Slope: this section. • Danaher—15 to 35 percent • Loberg—15 to 35 percent Management Elevation: 5,000 to 7,500 feet For management information about this map unit, Mean annual precipitation: 22 to 28 inches see appropriate sections in Part II of this publication. Frost-free period: 30 to 70 days 90 Soil Survey
Composition Taxonomic Class: Fine, smectitic, frigid Vertic Argiustolls Major Components Danaher and similar soils: 50 percent Typical Pedon Loberg and similar soils: 35 percent Danvers clay loam, 4 to 8 percent slopes, in an area Minor Components of irrigated pasture, 1,300 feet north and 2,450 feet Areas of rock outcrop: 0 to 4 percent west of the southeast corner of sec. 18, T. 7 N., Soils that are moderately deep: 0 to 4 percent R. 8 W. Soils that have slopes more than 35 percent: 0 to A1—0 to 4 inches; dark grayish brown (10YR 4/2) 4 percent clay loam, very dark grayish brown (10YR 3/2) Poorly drained soils: 0 to 3 percent moist; weak thin platy structure parting to Major Component Description moderate fine granular structure; slightly hard, very friable, slightly sticky, slightly plastic; many Danaher fine and few medium roots; many fine and Surface layer texture: Loam medium irregular pores; neutral; abrupt smooth Depth class: Very deep (more than 60 inches) boundary. Drainage class: Well drained A2—4 to 8 inches; dark grayish brown (10YR 4/2) Dominant parent material: Material weathered from clay loam, very dark grayish brown (10YR 3/2) igneous rocks moist; weak fine subangular blocky structure Native plant cover type: Forestland parting to moderate fine granular structure; Flooding: None slightly hard, very friable, moderately sticky, Available water capacity: Mainly 8.9 inches moderately plastic; many fine and few medium roots; many fine and common fine tubular Loberg irregular random pores; neutral; clear wavy Surface layer texture: Gravelly loam boundary. Depth class: Very deep (more than 60 inches) Bt—8 to 16 inches; brown (10YR 5/3) clay loam, dark Drainage class: Well drained brown (10YR 4/3) moist; moderate medium Dominant parent material: Material weathered from prismatic structure parting to strong fine and igneous rocks medium subangular blocky; very hard, friable, Native plant cover type: Forestland very sticky, very plastic; common fine roots; few Flooding: None fine tubular pores; common distinct brown (10YR Available water capacity: Mainly 4.7 inches 5/3) clay films on all surfaces; slightly alkaline; clear wavy boundary. A typical soil description with range in Btk—16 to 21 inches; pale brown (10YR 6/3) clay characteristics is included, in alphabetical order, in loam, brown (10YR 5/3) moist; moderate medium this section. subangular blocky structure; hard, friable, Management moderately sticky, very plastic; common fine roots; common fine tubular random pores; few For management information about this map unit, faint clay films on faces of peds; many fine and see appropriate sections in Part II of this publication. medium masses of lime; strongly effervescent; moderately alkaline; clear wavy boundary. Danvers Series Bk1—21 to 38 inches; white (10YR 8/1) clay loam, pale brown (10YR 6/3) moist; weak fine Depth class: Very deep subangular blocky structure; slightly hard, very Drainage class: Well drained friable, moderately sticky, moderately plastic; Permeability: Slow common fine roots; many fine and few medium Landform: Alluvial fans and stream terraces tubular random pores; 5 percent pebbles; Parent material: Calcareous alluvium disseminated lime; prominent lime casts on Slope range: 0 to 60 percent bottom of pebbles; violently effervescent; strongly Elevation range: 3,800 to 5,800 feet alkaline; gradual wavy boundary. Annual precipitation: 15 to 19 inches Bk2—38 to 60 inches; light brownish gray (10YR 6/2) Annual air temperature: 39 to 44 degrees F gravelly clay loam, grayish brown (2.5Y 5/2) Frost-free period: 70 to 90 days moist; weak fine subangular blocky structure; Powell County Area, Montana—Part I 91
hard, friable, moderately sticky, moderately Chroma: 1 to 3 plastic; common fine random tubular and irregular Texture: Silty clay, clay loam, silty clay loam, or pores; 5 percent cobbles and 10 percent pebbles; clay disseminated lime; prominent lime casts on Clay content: 30 to 45 percent bottom of rock fragments; violently effervescent; Content of rock fragments: 0 to 15 percent—0 to strongly alkaline. 5 percent stones and cobbles; 0 to 10 percent pebbles Range in Characteristics Calcium carbonate equivalent: 20 to 40 percent Soil temperature: 41 to 47 degrees F Reaction: pH 7.4 to 8.4 Moisture control section: Between depths of 4 and 12 inches; never dry in all parts of the moisture control section for 45 consecutive days 49B—Danvers clay loam, Thickness of the mollic epipedon: 7 to 12 inches 0 to 4 percent slopes Depth to the calcic horizon: 14 to 25 inches Soil phases: Stony Setting A horizons Hue: 7.5YR, 10YR, or 2.5Y Landform: Alluvial fans and stream terraces Value: 4 or 5 dry; 2 or 3 moist Slope: 0 to 4 percent Chroma: 2 or 3 Elevation: 3,800 to 5,000 feet Clay content: 27 to 35 percent Mean annual precipitation: 15 to 19 inches Content of rock fragments: 0 to 35 percent—0 to Frost-free period: 70 to 90 days 15 percent stones and cobbles; 0 to 20 percent pebbles Composition Reaction: pH 6.1 to 7.8 Major Components Bt horizon Danvers and similar soils: 85 percent Hue: 7.5YR, 10YR, or 2.5Y Value: 4 or 5 dry; 3 or 4 moist Minor Components Chroma: 2 or 3 Danvers cobbly clay loam: 0 to 4 percent Texture: Silty clay loam, clay loam, silty clay, or Soils that have slopes more than 4 percent: 0 to clay 4 percent Clay content: 35 to 50 percent Soils that are very gravelly throughout: 0 to 4 percent Content of rock fragments: 0 to 15 percent—0 to Soils that are calcareous throughout: 0 to 3 percent 5 percent stones and cobbles; 0 to 10 percent pebbles Major Component Description Reaction: pH 6.6 to 8.4 Surface layer texture: Clay loam Btk horizon Depth class: Very deep (more than 60 inches) Hue: 7.5YR, 10YR, or 2.5Y Drainage class: Well drained Value: 5 to 7 dry; 4 to 6 moist Dominant parent material: Alluvium Chroma: 2 or 3 Native plant cover type: Rangeland Texture: Clay, clay loam, or silty clay loam Flooding: None Clay content: 35 to 45 percent Available water capacity: Mainly 8.8 inches Content of rock fragments: 0 to 15 percent—0 to 5 percent stones and cobbles; 0 to 10 percent A typical soil description with range in pebbles characteristics is included, in alphabetical order, in Calcium carbonate equivalent: 10 to 20 percent this section. Reaction: pH 7.4 to 8.4 Management Bk horizons Hue: 7.5YR, 10YR, or 2.5Y For management information about this map unit, Value: 6 to 8 dry; 5 or 6 moist see appropriate sections in Part II of this publication. 92 Soil Survey
49C—Danvers clay loam, Minor Components 4 to 8 percent slopes Danvers cobbly clay loam: 0 to 4 percent Soils that have slopes more than 15 percent: 0 to 4 percent Setting Soils that are very gravelly throughout: 0 to 4 percent Landform: Alluvial fans and stream terraces Soils that are calcareous throughout: 0 to 3 percent Slope: 4 to 8 percent Elevation: 3,800 to 5,000 feet Major Component Description Mean annual precipitation: 15 to 19 inches Frost-free period: 70 to 90 days Surface layer texture: Clay loam Depth class: Very deep (more than 60 inches) Composition Drainage class: Well drained Major Components Dominant parent material: Alluvium Danvers and similar soils: 85 percent Native plant cover type: Rangeland Flooding: None Minor Components Available water capacity: Mainly 8.8 inches Soils that have a cobbly surface layer: 0 to 4 percent Soils that have slopes more than 8 percent: 0 to A typical soil description with range in 4 percent characteristics is included, in alphabetical order, in Soils that are very gravelly throughout: 0 to 4 percent this section. Soils that are calcareous throughout: 0 to 3 percent Management Major Component Description For management information about this map unit, Surface layer texture: Clay loam see appropriate sections in Part II of this publication. Depth class: Very deep (more than 60 inches) Drainage class: Well drained Dominant parent material: Alluvium Native plant cover type: Rangeland 149B—Danvers cobbly clay loam, Flooding: None 0 to 4 percent slopes Available water capacity: Mainly 8.8 inches Setting A typical soil description with range in characteristics is included, in alphabetical order, in Landform: Alluvial fans and stream terraces this section. Slope: 0 to 4 percent Elevation: 3,800 to 5,000 feet Management Mean annual precipitation: 15 to 19 inches For management information about this map unit, Frost-free period: 70 to 90 days see appropriate sections in Part II of this publication. Composition Major Components 49D—Danvers clay loam, Danvers and similar soils: 85 percent 8 to 15 percent slopes Minor Components Soils that have slopes more than 4 percent: 0 to Setting 15 percent Landform: Alluvial fans Major Component Description Slope: 8 to 15 percent Elevation: 3,800 to 5,000 feet Surface layer texture: Cobbly clay loam Mean annual precipitation: 15 to 19 inches Depth class: Very deep (more than 60 inches) Frost-free period: 70 to 90 days Drainage class: Well drained Dominant parent material: Alluvium Composition Native plant cover type: Rangeland Major Components Flooding: None Danvers and similar soils: 85 percent Available water capacity: Mainly 9.1 inches Powell County Area, Montana—Part I 93
A typical soil description with range in Mean annual precipitation: 15 to 19 inches characteristics is included, in alphabetical order, in Frost-free period: 70 to 90 days this section. Composition Management Major Components For management information about this map unit, Danvers and similar soils: 85 percent see appropriate sections in Part II of this publication. Minor Components Soils that have slopes more than 15 percent: 0 to 8 percent 149C—Danvers cobbly clay loam, Roy soils: 0 to 7 percent 4 to 8 percent slopes Major Component Description Surface layer texture: Cobbly clay loam Setting Depth class: Very deep (more than 60 inches) Landform: Alluvial fans and stream terraces Drainage class: Well drained Slope: 4 to 8 percent Dominant parent material: Alluvium Elevation: 3,800 to 5,000 feet Native plant cover type: Rangeland Mean annual precipitation: 15 to 19 inches Flooding: None Frost-free period: 70 to 90 days Available water capacity: Mainly 9.1 inches Composition A typical soil description with range in Major Components characteristics is included, in alphabetical order, in Danvers and similar soils: 85 percent this section. Minor Components Management Soils that have slopes more than 8 percent: 0 to For management information about this map unit, 15 percent see appropriate sections in Part II of this publication. Major Component Description Surface layer texture: Cobbly clay loam 446B—Danvers-Roy complex, Depth class: Very deep (more than 60 inches) 0 to 4 percent slopes Drainage class: Well drained Dominant parent material: Alluvium Setting Native plant cover type: Rangeland Flooding: None Landform: Available water capacity: Mainly 9.1 inches • Danvers—Alluvial fans • Roy—Alluvial fans A typical soil description with range in Slope: characteristics is included, in alphabetical order, in • Danvers—0 to 4 percent this section. • Roy—0 to 4 percent Elevation: 3,800 to 5,000 feet Management Mean annual precipitation: 15 to 19 inches Frost-free period: 70 to 90 days For management information about this map unit, see appropriate sections in Part II of this publication. Composition Major Components 149D—Danvers cobbly clay loam, Danvers and similar soils: 50 percent 8 to 15 percent slopes Roy and similar soils: 35 percent Minor Components Setting Soils that have slopes more than 4 percent: 0 to Landform: Alluvial fans and stream terraces 5 percent Slope: 8 to 15 percent Danvers cobbly loam: 0 to 5 percent Elevation: 3,800 to 5,000 feet Winspect soils: 0 to 5 percent 94 Soil Survey
Major Component Description Major Component Description Danvers Danvers Surface layer texture: Clay loam Surface layer texture: Clay loam Depth class: Very deep (more than 60 inches) Depth class: Very deep (more than 60 inches) Drainage class: Well drained Drainage class: Well drained Dominant parent material: Alluvium Dominant parent material: Alluvium Native plant cover type: Rangeland Native plant cover type: Rangeland Flooding: None Flooding: None Available water capacity: Mainly 8.8 inches Available water capacity: Mainly 8.8 inches
Roy Roy Surface layer texture: Gravelly loam Surface layer texture: Gravelly loam Depth class: Very deep (more than 60 inches) Depth class: Very deep (more than 60 inches) Drainage class: Well drained Drainage class: Well drained Dominant parent material: Alluvium Dominant parent material: Alluvium Native plant cover type: Rangeland Native plant cover type: Rangeland Flooding: None Flooding: None Available water capacity: Mainly 4.7 inches Available water capacity: Mainly 4.7 inches
A typical soil description with range in A typical soil description with range in characteristics is included, in alphabetical order, in characteristics is included, in alphabetical order, in this section. this section. Management Management For management information about this map unit, For management information about this map unit, see appropriate sections in Part II of this publication. see appropriate sections in Part II of this publication.
446C—Danvers-Roy complex, 446D—Danvers-Roy complex, 4 to 8 percent slopes 8 to 15 percent slopes Setting Setting Landform: Landform: • Danvers—Alluvial fans • Danvers—Alluvial fans • Roy—Alluvial fans • Roy—Alluvial fans Slope: Slope: • Danvers—4 to 8 percent • Danvers—8 to 15 percent • Roy—4 to 8 percent • Roy—8 to 15 percent Elevation: 3,800 to 5,000 feet Elevation: 3,800 to 5,000 feet Mean annual precipitation: 15 to 19 inches Mean annual precipitation: 15 to 19 inches Frost-free period: 70 to 90 days Frost-free period: 70 to 90 days Composition Composition Major Components Major Components Danvers and similar soils: 50 percent Danvers and similar soils: 50 percent Roy and similar soils: 35 percent Roy and similar soils: 35 percent Minor Components Minor Components Soils that have slopes more than 8 percent: 0 to Soils that have slopes more than 15 percent: 0 to 5 percent 5 percent Winspect soils: 0 to 5 percent Cobbly loam soils: 0 to 5 percent Danvers cobbly loam: 0 to 5 percent Winspect soils: 0 to 5 percent Powell County Area, Montana—Part I 95
Major Component Description nonplastic; many very fine and fine and few medium roots; many very fine irregular pores; Danvers 20 percent channers; neutral; clear smooth Surface layer texture: Clay loam boundary. Depth class: Very deep (more than 60 inches) Bw—8 to 16 inches; brown (10YR 5/3) very channery Drainage class: Well drained loam, dark brown (10YR 4/3) moist; weak Dominant parent material: Alluvium medium subangular blocky structure; slightly Native plant cover type: Rangeland hard, friable, slightly sticky, moderately plastic; Flooding: None many very fine and fine roots; many very fine Available water capacity: Mainly 8.8 inches irregular pores; 40 percent channers; neutral; clear smooth boundary. Roy Bk—16 to 32 inches; light brownish gray (2.5Y 6/2) Surface layer texture: Gravelly loam very channery loam, grayish brown (2.5Y 5/2) Depth class: Very deep (more than 60 inches) moist; weak medium granular structure; slightly Drainage class: Well drained hard, firm, slightly sticky, moderately plastic; Dominant parent material: Alluvium common very fine and fine roots; common very Native plant cover type: Rangeland fine irregular pores; 45 percent channers; Flooding: None disseminated lime; violently effervescent; Available water capacity: Mainly 4.7 inches moderately alkaline; clear smooth boundary. Cr—32 to 60 inches; light yellowish brown (2.5Y 6/4) A typical soil description with range in semiconsolidated sandstone. characteristics is included, in alphabetical order, in this section. Range in Characteristics Management Soil temperature: 41 to 46 degrees F For management information about this map unit, Moisture control section: Between depths of 4 and see appropriate sections in Part II of this publication. 12 inches; dry in all parts between four-tenths and five-tenths of the cumulative days per year when the soil temperature at a depth of 20 inches Dolus Series is 41 degrees F or higher Thickness of the mollic epipedon: 7 to 10 inches Depth class: Moderately deep Depth to the Cr horizon: 20 to 40 inches Drainage class: Well drained A horizon Permeability: Moderate Chroma: 2 or 3 Landform: Hills Clay content: 15 to 25 percent Parent material: Semiconsolidated sedimentary beds Content of rock fragments: 15 to 25 percent—0 to Slope range: 4 to 45 percent 5 percent cobbles; 15 to 20 percent channers Elevation range: 3,600 to 5,200 feet Reaction: pH 6.6 to 7.3 Annual precipitation: 10 to 14 inches Annual air temperature: 39 to 44 degrees F Bw horizon Frost-free period: 90 to 105 days Value: 4 or 5 dry; 3 or 4 moist Chroma: 2 to 4 Taxonomic Class: Loamy-skeletal, mixed, Clay content: 15 to 27 percent superactive, frigid Aridic Haplustolls Content of rock fragments: 35 to 50 percent—0 to 10 percent flagstones; 35 to 40 percent Typical Pedon channers Dolus channery loam, in an area of Dolus-Castner Calcium carbonate equivalent: 0 to 5 percent channery loams, 15 to 45 percent slopes, in an area Reaction: pH 6.6 to 7.3 of rangeland, 1,600 feet south and 650 feet west of Bk horizon the northeast corner of sec. 9, T. 9 N., R. 9 W. Hue: 2.5Y or 10YR A—0 to 8 inches; brown (10YR 5/3) channery loam, Value: 5 or 6 dry; 4 to 6 moist dark brown (10YR 3/3) moist; moderate medium Chroma: 2 or 3 granular structure; slightly hard, friable, nonsticky, Clay content: 15 to 27 percent 96 Soil Survey
Content of rock fragments: 40 to 60 percent—0 to A typical soil description with range in 15 percent flagstones; 40 to 45 percent characteristics is included, in alphabetical order, in channers this section. Calcium carbonate equivalent: 5 to 15 percent Management Reaction: pH 7.4 to 8.4 For management information about this map unit, Cr horizon see appropriate sections in Part II of this publication. Semiconsolidated sedimentary beds
168C—Dolus-Boxwell complex, 168D—Dolus-Boxwell complex, 4 to 8 percent slopes 8 to 15 percent slopes
Setting Setting Landform: Landform: • Dolus—Hills • Dolus—Hills • Boxwell—Hills • Boxwell—Hills Slope: Slope: • Dolus—4 to 8 percent • Dolus—8 to 15 percent • Boxwell—4 to 8 percent • Boxwell—8 to 15 percent Elevation: 4,000 to 5,200 feet Elevation: 4,000 to 5,200 feet Mean annual precipitation: 10 to 14 inches Mean annual precipitation: 10 to 14 inches Frost-free period: 90 to 105 days Frost-free period: 90 to 105 days Composition Composition Major Components Major Components Dolus and similar soils: 55 percent Dolus and similar soils: 55 percent Boxwell and similar soils: 30 percent Boxwell and similar soils: 30 percent Minor Components Minor Components Soils that are shallow to bedrock: 0 to 10 percent Soils that are shallow to bedrock: 0 to 10 percent Areas of rock outcrop: 0 to 5 percent Areas of rock outcrop: 0 to 5 percent Major Component Description Major Component Description Dolus Dolus Surface layer texture: Channery loam Surface layer texture: Channery loam Depth class: Moderately deep (20 to 40 inches) Depth class: Moderately deep (20 to 40 inches) Drainage class: Well drained Drainage class: Well drained Dominant parent material: Semiconsolidated Dominant parent material: Semiconsolidated sedimentary beds sedimentary beds Native plant cover type: Rangeland Native plant cover type: Rangeland Flooding: None Flooding: None Available water capacity: Mainly 3.1 inches Available water capacity: Mainly 3.1 inches
Boxwell Boxwell Surface layer texture: Loam Surface layer texture: Loam Depth class: Moderately deep (20 to 40 inches) Depth class: Moderately deep (20 to 40 inches) Drainage class: Well drained Drainage class: Well drained Dominant parent material: Semiconsolidated Dominant parent material: Semiconsolidated sedimentary beds sedimentary beds Native plant cover type: Rangeland Native plant cover type: Rangeland Flooding: None Flooding: None Available water capacity: Mainly 6.2 inches Available water capacity: Mainly 6.2 inches Powell County Area, Montana—Part I 97
A typical soil description with range in A typical soil description with range in characteristics is included, in alphabetical order, in characteristics is included, in alphabetical order, in this section. this section. Management Management For management information about this map unit, For management information about this map unit, see appropriate sections in Part II of this publication. see appropriate sections in Part II of this publication.
168E—Dolus-Boxwell complex, 268F—Dolus-Castner channery loams, 15 to 35 percent slopes 15 to 45 percent slopes
Setting Setting Landform: Landform: • Dolus—Hills • Dolus—Hills • Boxwell—Hills • Castner—Hills Slope: Slope: • Dolus—15 to 35 percent • Dolus—15 to 45 percent • Boxwell—15 to 35 percent • Castner—15 to 45 percent Elevation: 4,000 to 5,200 feet Elevation: 3,600 to 5,200 feet Mean annual precipitation: 10 to 14 inches Mean annual precipitation: 10 to 14 inches Frost-free period: 90 to 105 days Frost-free period: 90 to 105 days Composition Composition Major Components Major Components Dolus and similar soils: 55 percent Dolus and similar soils: 45 percent Boxwell and similar soils: 30 percent Castner and similar soils: 40 percent Minor Components Minor Components Soils that are shallow to bedrock: 0 to 10 percent Areas of rock outcrop: 0 to 8 percent Areas of rock outcrop: 0 to 5 percent Soils that are calcareous throughout: 0 to 7 percent Major Component Description Major Component Description Dolus Surface layer texture: Channery loam Dolus Depth class: Moderately deep (20 to 40 inches) Surface layer texture: Channery loam Drainage class: Well drained Depth class: Moderately deep (20 to 40 inches) Dominant parent material: Semiconsolidated Drainage class: Well drained sedimentary beds Dominant parent material: Semiconsolidated Native plant cover type: Rangeland sedimentary beds Flooding: None Native plant cover type: Rangeland Available water capacity: Mainly 3.1 inches Flooding: None Available water capacity: Mainly 3.1 inches Boxwell Surface layer texture: Loam Castner Depth class: Moderately deep (20 to 40 inches) Surface layer texture: Channery loam Drainage class: Well drained Depth class: Shallow (10 to 20 inches) Dominant parent material: Semiconsolidated Drainage class: Well drained sedimentary beds Dominant parent material: Sandstone residuum Native plant cover type: Rangeland Native plant cover type: Rangeland Flooding: None Flooding: None Available water capacity: Mainly 6.2 inches Available water capacity: Mainly 1.6 inches 98 Soil Survey
A typical soil description with range in fine subangular blocky structure; hard, friable, characteristics is included, in alphabetical order, in moderately sticky, moderately plastic; common this section. very fine and fine roots; few very fine and fine discontinuous pores; 10 percent pebbles; Management common lime pendants; strongly effervescent; For management information about this map unit, moderately alkaline; gradual wavy boundary. see appropriate sections in Part II of this publication. Cr—32 to 60 inches; white (10YR 8/1) semiconsolidated siltstone that crushes to silty clay loam. Doney Series Range in Characteristics Depth class: Moderately deep Soil temperature: 41 to 47 degrees F Drainage class: Well drained Moisture control section: Between depths of 4 and Permeability: Moderate 12 inches Landform: Hills Depth to bedrock: 20 to 40 inches Parent material: Semiconsolidated sedimentary beds Slope range: 15 to 45 percent A horizon Elevation range: 3,600 to 5,000 feet Hue: 10YR or 2.5Y Annual precipitation: 10 to 14 inches Value: 5 or 6 dry; 4 or 5 moist Annual air temperature: 39 to 45 degrees F Chroma: 1 to 3 Frost-free period: 90 to 105 days Clay content: 18 to 27 percent Content of rock fragments: 15 to 35 percent—0 to Taxonomic Class: Fine-loamy, mixed, superactive, 10 percent flagstones; 15 to 25 percent frigid Typic Haplustepts pebbles Reaction: pH 6.6 to 8.4 Typical Pedon Bw horizon Doney channery loam, in an area of Doney-Dolus Hue: 10YR or 2.5Y channery loams, 15 to 45 percent slopes, in an area Value: 5 to 7 dry; 4 to 6 moist of rangeland, 1,500 feet north and 400 feet west of Chroma: 2 to 4 the southeast corner of sec. 10, T. 9 N., R. 10 W. Texture: Loam, clay loam, or silty clay loam A—0 to 4 inches; gray (10YR 6/1) channery loam, Clay content: 18 to 30 percent grayish brown (10YR 5/2) moist; weak medium Content of rock fragments: 0 to 35 percent—0 to granular structure; soft, very friable, moderately 10 percent cobbles; 0 to 25 percent pebbles sticky, moderately plastic; many fine, medium, Calcium carbonate equivalent: Less than and coarse roots; many very fine and fine 15 percent discontinuous irregular pores; 15 percent Reaction: pH 7.9 to 9.0 channers; strongly effervescent; moderately Bk horizon alkaline; clear smooth boundary. Hue: 10YR or 2.5Y Bw—4 to 11 inches; light brownish gray (10YR 6/2) Value: 6 or 7 dry; 5 or 6 moist gravelly silty clay loam, brown (10YR 4/3) moist; Chroma: 2 to 4 moderate medium subangular blocky structure Texture: Loam, clay loam, or silty clay loam parting to moderate medium granular structure; Clay content: 18 to 30 percent slightly hard, friable, moderately sticky, Content of rock fragments: 0 to 30 percent—0 to moderately plastic; many fine, medium, and 10 percent cobbles; 0 to 20 percent pebbles or coarse roots; common very fine and fine channers discontinuous pores; 15 percent pebbles; strongly Calcium carbonate equivalent: 5 to 15 percent effervescent; moderately alkaline; gradual smooth Reaction: pH 7.9 to 9.0 boundary. Bk—11 to 32 inches; light gray (2.5Y 7/2) silty clay Cr horizon loam, light brownish gray (2.5Y 6/2) moist; weak Semiconsolidated sedimentary beds Powell County Area, Montana—Part I 99
169F—Doney-Dolus channery loams, Dougcliff Series 15 to 45 percent slopes Depth class: Very deep Drainage class: Very poorly drained Setting Permeability: Moderately rapid Landform: Landform: Closed depressions • Doney—Hills Parent material: Mucky peat • Dolus—Hills Slope range: 0 to 2 percent Slope: Elevation range: 3,500 to 5,600 feet • Doney—15 to 45 percent Annual precipitation: 10 to 19 inches • Dolus—15 to 45 percent Annual air temperature: 38 to 42 degrees F Elevation: 3,600 to 5,000 feet Frost-free period: 70 to 90 days Mean annual precipitation: 10 to 14 inches Frost-free period: 90 to 105 days Taxonomic Class: Euic, frigid Typic Haplofibrists Composition Typical Pedon Major Components Dougcliff mucky peat, 0 to 2 percent slopes, ponded, Doney and similar soils: 50 percent 200 feet north and 300 feet east of the southwest Dolus and similar soils: 35 percent corner of sec. 2, T. 7 N., R. 10 W. Minor Components Oi1—0 to 13 inches; black (10YR 2/1) mucky peat, Soils that are shallow to bedrock: 0 to 10 percent very dark gray (10YR 3/1) dry; about 80 percent Areas of rock outcrop: 0 to 5 percent fiber and raw herbaceous plant material, 70 percent rubbed; massive; nonsticky and Major Component Description nonplastic; slightly acid; clear smooth boundary. Doney Oi2—13 to 27 inches; black (10YR 2/1) mucky peat, Surface layer texture: Channery loam black (10YR 2/1) dry; about 85 percent fiber, Depth class: Moderately deep (20 to 40 inches) 80 percent rubbed; massive; nonsticky and Drainage class: Well drained nonplastic; slightly acid; clear smooth boundary. Dominant parent material: Semiconsolidated Oi3—27 to 60 inches; black (10YR 2/1) mucky peat, sedimentary beds very dark gray (10YR 3/1) dry; about 80 percent Native plant cover type: Rangeland fiber, 75 percent rubbed; massive; nonsticky and Flooding: None nonplastic; slightly acid. Available water capacity: Mainly 4.9 inches Range in Characteristics Dolus Soil temperature: 40 to 47 degrees F Surface layer texture: Channery loam Depth of organic material: Greater than 51 inches Depth class: Moderately deep (20 to 40 inches) Depth to the seasonal high water table: 0 to 6 inches Drainage class: Well drained Other features: Some pedons have mineral materials Dominant parent material: Semiconsolidated at depths of 51 to 60 inches. Some pedons have sedimentary beds an Oe horizon. Native plant cover type: Rangeland Oi1 horizon Flooding: None Hue: 10YR or 7.5YR Available water capacity: Mainly 3.1 inches Value: 2 moist Chroma: 1 or 2 A typical soil description with range in Fiber content: 80 to 90 percent unrubbed, 65 to characteristics is included, in alphabetical order, in 75 percent rubbed this section. Reaction: pH 6.1 to 7.8 Management Oi2 horizon For management information about this map unit, Hue: 10YR, 7.5YR, or 5YR see appropriate sections in Part II of this publication. Value: 2 or 3 moist 100 Soil Survey
Chroma: 1 or 2 103—Dumps, mine Fiber content: 85 to 95 percent unrubbed, 75 to 85 percent rubbed Setting Reaction: pH 6.1 to 7.8 Landform: Stream terraces Oi3 horizon Slope: 4 to 35 percent Hue: 10YR, 7.5YR, or 5YR Elevation: 3,500 to 5,600 feet Value: 2 or 3 moist Mean annual precipitation: 15 to 19 inches Fiber content: 80 to 90 percent unrubbed, 70 to Frost-free period: 70 to 105 days 80 percent rubbed Reaction: pH 6.1 to 7.8 Composition Major Components 2—Dougcliff mucky peat, Dumps, mine: 85 percent 0 to 2 percent slopes, ponded Minor Components Areas of soils that support vegetation: 0 to 15 percent Setting Major Component Description Landform: Closed depressions Definition: Consists of mine waste from placer mining Slope: 0 to 2 percent activities Elevation: 3,500 to 5,600 feet Surface layer texture: Variable Mean annual precipitation: 10 to 19 inches Depth class: Very deep (more than 60 inches) Frost-free period: 70 to 90 days Flooding: None Composition Available water capacity: Mainly 0.9 inches Major Components Dougcliff and similar soils: 85 percent DUMPS—Dumps, sanitary landfill Minor Components Poorly drained soils: 0 to 10 percent Composition Areas of open water: 0 to 5 percent Major Components Major Component Description Dumps, sanitary landfill: 100 percent Surface layer texture: Mucky-peat Major Component Description Depth class: Very deep (more than 60 inches) Definition: Areas that have been utilized for disposal Drainage class: Very poorly drained of household and industrial waste. Soils Dominant parent material: Peat previously present have been highly disturbed Native plant cover type: Rangeland when used as daily cover in burying refuse. Flooding: None Water table: Apparent Ponding: Very long Elkner Series Available water capacity: Mainly 21.0 inches Depth class: Very deep A typical soil description with range in Drainage class: Somewhat excessively drained characteristics is included, in alphabetical order, in Permeability: Moderately rapid to BC, rapid below this section. Landform: Mountains Parent material: Granitic colluvium Management Slope range: 8 to 60 percent For management information about this map unit, Elevation range: 4,600 to 7,500 feet see appropriate sections in Part II of this publication. Annual precipitation: 20 to 30 inches Powell County Area, Montana—Part I 101
Annual air temperature: 35 to 38 degrees F Range in Characteristics Frost-free period: 30 to 70 days Soil temperature: 39 to 44 degrees F Moisture control section: Between depths of 8 and Taxonomic Class: Coarse-loamy, mixed, superactive 24 inches Lamellic Eutrocryepts E horizons Typical Pedon Value: 6 or 7 dry; 3 to 5 moist Elkner stony sandy loam, in an area of Elkner- Chroma: 2 to 4 Ovando complex, 15 to 35 percent slopes, in an area Texture: Sandy loam or coarse sandy loam of woodland, 1,600 feet south and 2,640 feet east of Clay content: 5 to 10 percent the northwest corner of sec. 30, T. 13 N., R. 13 W. Content of rock fragments: 0 to 35 percent—0 to 35 percent boulders, stones, and cobbles; 0 to Oi—3 to 0 inches; undecomposed and slightly 20 percent pebbles decomposed forest litter. Reaction: pH 5.6 to 6.5 E1—0 to 7 inches; pale brown (10YR 6/3) stony sandy loam, brown (10YR 4/3) moist; weak E and Bt horizons medium granular structure; soft, very friable, Hue: E part—10YR; B part—10YR or 2.5Y nonsticky, nonplastic; many very fine, fine, and Value: E part—6 or 7 dry, 4 or 5 moist; B part— medium and few coarse roots; 5 percent stones, 4 or 5 dry, 4 or 5 moist 5 percent cobbles, and 5 percent pebbles; Chroma: E part—2 to 4; B part—3 or 4 moderately acid; clear wavy boundary. Texture: Coarse sandy loam or sandy loam E2—7 to 16 inches; light yellowish brown (10YR 6/4) Clay content: 5 to 10 percent; lamellae have less stony coarse sandy loam, brown (10YR 4/3) than 3 percent increase in clay moist; weak medium subangular blocky structure; Content of rock fragments: 0 to 20 percent—0 to soft, very friable, nonsticky, nonplastic; many 15 percent boulders, stones, and cobbles; 5 to very fine, fine, and medium and few coarse 20 percent pebbles roots; 5 percent stones, 5 percent cobbles, and Reaction: pH 5.6 to 6.5 5 percent pebbles; slightly acid; clear wavy BC horizon boundary. Hue: 10YR or 2.5Y E and Bt1—16 to 26 inches; 75 percent is light Value: 5 to 7 dry; 3 to 5 moist yellowish brown (10YR 6/4) coarse sandy loam, Chroma: 2 to 4 brown (10YR 4/3) moist (E part); 25 percent is Texture: Loamy coarse sand or coarse sandy yellowish brown (10YR 5/4) coarse sandy loam 1 1 loam lamellae /8- to /4-inch thick, dark yellowish brown Clay content: 0 to 5 percent (10YR 4/4) moist (B part); weak coarse Content of rock fragments: 0 to 35 percent—0 to subangular blocky structure; slightly hard, very 20 percent stones or cobbles; 5 to 20 percent friable, nonsticky, nonplastic; common very fine, pebbles fine, and medium roots; 5 percent cobbles and Reaction: pH 5.6 to 6.5 5 percent pebbles; moderately acid; clear wavy boundary. E and Bt2—26 to 36 inches; 75 percent is light yellowish brown (10YR 6/4) coarse sandy loam, 80E—Elkner-Ovando complex, brown (10YR 4/3) moist (E part); 25 percent is 15 to 35 percent slopes yellowish brown (10YR 5/4) coarse sandy loam 1 1 lamellae /8- to /4-inch thick, dark yellowish brown Setting (10YR 4/4) moist (B part); weak coarse subangular blocky structure; slightly hard, very Landform: friable, nonsticky, nonplastic; common very fine • Elkner—Mountains and fine roots; 5 percent cobbles and 5 percent • Ovando—Mountains pebbles; slightly acid; gradual wavy boundary. Slope: BC—36 to 60 inches; light yellowish brown (10YR • Elkner—15 to 35 percent 6/4) stony loamy coarse sand, brown (10YR 4/3) • Ovando—15 to 35 percent moist; single grain; loose, nonsticky, nonplastic; Elevation: 4,600 to 7,000 feet 15 percent stones, 5 percent cobbles, and Mean annual precipitation: 24 to 30 inches 5 percent pebbles; slightly acid. Frost-free period: 30 to 70 days 102 Soil Survey
Composition Composition Major Components Major Components Elkner and similar soils: 45 percent Elkner and similar soils: 45 percent Ovando and similar soils: 40 percent Ovando and similar soils: 40 percent Minor Components Minor Components Areas of rock outcrop: 0 to 5 percent Areas of rock outcrop: 0 to 5 percent Soils that are sandy below 7 inches: 0 to 5 percent Soils that are sandy below 7 inches: 0 to 5 percent Soils that are very gravelly below 10 inches: 0 to Soils that are very gravelly below 10 inches: 0 to 5 percent 5 percent Major Component Description Major Component Description Elkner Elkner Surface layer texture: Stony sandy loam Surface layer texture: Stony sandy loam Depth class: Very deep (more than 60 inches) Depth class: Very deep (more than 60 inches) Drainage class: Somewhat excessively drained Drainage class: Somewhat excessively drained Dominant parent material: Colluvium Dominant parent material: Colluvium Native plant cover type: Forestland Native plant cover type: Forestland Flooding: None Flooding: None Available water capacity: Mainly 4.4 inches Available water capacity: Mainly 4.4 inches
Ovando Ovando Surface layer texture: Very stony sandy loam Surface layer texture: Very stony sandy loam Depth class: Very deep (more than 60 inches) Depth class: Very deep (more than 60 inches) Drainage class: Excessively drained Drainage class: Excessively drained Dominant parent material: Granitic colluvium Dominant parent material: Granitic colluvium Native plant cover type: Forestland Native plant cover type: Forestland Flooding: None Flooding: None Available water capacity: Mainly 2.0 inches Available water capacity: Mainly 2.0 inches
A typical soil description with range in A typical soil description with range in characteristics is included, in alphabetical order, in characteristics is included, in alphabetical order, in this section. this section. Management Management For management information about this map unit, For management information about this map unit, see appropriate sections in Part II of this publication. see appropriate sections in Part II of this publication.
80F—Elkner-Ovando complex, Elliston Series 35 to 60 percent slopes Depth class: Very deep Drainage class: Somewhat poorly drained Permeability: Moderate Setting Landform: Flood plains Landform: Parent material: Loamy alluvium • Elkner—Mountains Slope range: 0 to 4 percent • Ovando—Mountains Elevation range: 3,800 to 5,000 feet Slope: Annual precipitation: 15 to 19 inches • Elkner—35 to 60 percent Annual air temperature: 38 to 42 degrees F • Ovando—35 to 60 percent Frost-free period: 70 to 90 days Elevation: 4,600 to 7,000 feet Mean annual precipitation: 24 to 30 inches Taxonomic Class: Fine-loamy, mixed, superactive, Frost-free period: 30 to 70 days frigid Aquic Haplustepts Powell County Area, Montana—Part I 103
Typical Pedon Bw horizon Value: 3 or 4 moist; 5 or 6 dry Elliston loam, 0 to 4 percent slopes, rarely flooded, in Clay content: 18 to 27 percent an area of woodland, 2,600 feet south and 1,200 feet Content of rock fragments: 0 to 10 percent west of the northeast corner of sec. 26, T. 14 N., pebbles R. 11 W. Reaction: pH 7.9 to 8.4 Oi—1 to 0 inches; undecomposed and slightly Bk horizon decomposed forest litter. Value: 4 or 5 moist; 6 or 7 dry A—0 to 7 inches; light brownish gray (10YR 6/2) Chroma: 2 or 3 loam, grayish brown (10YR 5/2) moist; strong Clay content: 18 to 27 percent medium granular structure; slightly hard, friable, Content of rock fragments: 0 to 20 percent—0 to nonsticky, slightly plastic; many very fine and fine 10 percent cobbles; 0 to 10 percent pebbles and few very coarse roots; many very fine and Calcium carbonate equivalent: 5 to 15 percent fine interstitial pores; moderately alkaline; clear Reaction: pH 7.9 to 8.4 smooth boundary. Bw—7 to 12 inches; pale brown (10YR 6/3) loam, 2C horizon dark brown (10YR 3/3) moist; moderate fine Value: 4 or 5 moist; 5 to 7 dry subangular blocky structure; slightly hard, friable, Chroma: 2 or 3 nonsticky, slightly plastic; many very fine and fine Texture: Loam or sandy loam roots; many very fine and fine interstitial pores; Clay content: 8 to 20 percent slightly effervescent; moderately alkaline; gradual Content of rock fragments: 35 to 60 percent—0 to wavy boundary. 10 percent cobbles; 35 to 50 percent pebbles Bk—12 to 44 inches; light gray (10YR 7/2) loam, Reaction: 7.9 to 8.4 grayish brown (10YR 5/2) moist; many fine distinct yellowish red (5YR 5/8) redox concentrations; weak fine subangular blocky 6B—Elliston loam, 0 to 4 percent slopes, structure; slightly hard, friable, slightly sticky, rarely flooded slightly plastic; many very fine and fine roots; many very and fine interstitial pores; Setting disseminated lime; few fine masses of lime; Landform: Flood plains violently effervescent; moderately alkaline; Slope: 0 to 4 percent gradual wavy boundary. Elevation: 3,800 to 5,000 feet 2C—44 to 60 inches; light gray (10YR 7/2) very Mean annual precipitation: 15 to 19 inches gravelly loam, grayish brown (10YR 5/2) moist; Frost-free period: 70 to 90 days many fine distinct yellowish red (5YR 5/8) redox concentrations; massive; soft, friable, slightly Composition sticky, nonplastic; few fine roots; many very fine Major Components and fine interstitial pores; 40 percent pebbles; Elliston and similar soils: 85 percent strongly effervescent; moderately alkaline. Minor Components Range in Characteristics Poorly drained soils: 0 to 5 percent Soils that have a very gravelly subsoil: 0 to 4 percent Soil temperature: 40 to 46 degrees F Soils that have a sandy subsoil: 0 to 3 percent Moisture control section: Between depths of 4 and Soils that have slopes more than 4 percent: 0 to 12 inches 3 percent Depth to the Bk horizon: 6 to 24 inches Depth to the seasonal high water table: 24 to Major Component Description 42 inches Surface layer texture: Loam A horizon Depth class: Very deep (more than 60 inches) Value: 4 or 5 moist Drainage class: Somewhat poorly drained Chroma: 2 or 3 Dominant parent material: Alluvium Clay content: 18 to 27 percent Native plant cover type: Forestland Content of rock fragments: 0 to 10 percent Flooding: Rare pebbles Water table: Apparent Reaction: pH 7.9 to 8.4 Available water capacity: Mainly 8.6 inches 104 Soil Survey
A typical soil description with range in coarse roots; many very fine and fine interstitial characteristics is included, in alphabetical order, in pores; 25 percent cobbles and 55 percent this section. pebbles; slightly acid; clear wavy boundary. Bw2—26 to 40 inches; very pale brown (10YR 8/3) Management extremely gravelly sandy loam, brown (10YR 5/3) For management information about this map unit, moist; weak fine subangular blocky structure; see appropriate sections in Part II of this publication. slightly hard, very friable, slightly sticky, slightly plastic; common very fine and fine roots; many very fine and fine interstitial pores; 25 percent Elve Series cobbles and 65 percent pebbles; slightly acid; clear wavy boundary. Depth class: Very deep BC—40 to 60 inches; very pale brown (10YR 8/3) Drainage class: Somewhat excessively drained extremely gravelly sandy loam, brown (10YR 5/3) Permeability: Moderately rapid moist; massive; slightly hard, very friable, slightly Landform: Mountains, hills, and moraines sticky, slightly plastic; few very fine and fine roots; Parent material: Colluvium derived from quartzite, common very fine and fine interstitial pores; argillite, and alpine till 20 percent cobbles and 50 percent pebbles; Slope range: 4 to 80 percent slightly acid. Elevation range: 4,400 to 7,500 feet Range in Characteristics Annual precipitation: 20 to 30 inches Annual air temperature: 35 to 38 degrees F Soil temperature: 40 to 45 degrees F Frost-free period: 30 to 70 days Moisture control section: Between depths of 4 and 12 inches Taxonomic Class: Loamy-skeletal, mixed, A horizon superactive Ustic Eutrocryepts Hue: 7.5YR or 10YR Typical Pedon Value: 5 to 7 dry; 3 to 5 moist Chroma: 2 to 4 Elve gravelly loam, 35 to 60 percent slopes, in an Texture: Sandy loam or loam area of woodland, 1,700 feet south and 1,800 feet Clay content: 10 to 25 percent west of the northeast corner of sec. 24, T. 11 N., Content of rock fragments: 35 to 60 percent— R. 8 W. 15 to 30 percent stones and cobbles; 20 to Oe—2 to 0 inches; partially decomposed forest litter. 30 percent pebbles A—0 to 5 inches; light gray (10YR 7/2) gravelly loam, Reaction: pH 5.6 to 6.5 brown (10YR 5/3) moist; weak fine granular E horizon structure; soft, very friable, slightly sticky, slightly Hue: 7.5YR or 10YR plastic; many very fine and fine, common Value: 6 or 7 dry; 4 or 5 moist medium, and few coarse roots; many very fine Chroma: 2 to 4 and fine interstitial pores; 15 percent cobbles and Texture: Loam or sandy loam 20 percent pebbles; moderately acid; clear wavy Clay content: 5 to 25 percent boundary. Content of rock fragments: 35 to 85 percent—0 to E—5 to 16 inches; very pale brown (10YR 7/3) very 25 percent stones; 10 to 40 percent cobbles; gravelly sandy loam, yellowish brown (10YR 5/4) 20 to 35 percent pebbles moist; weak medium subangular blocky structure; Reaction: pH 5.1 to 7.3 slightly hard, very friable, slightly sticky, slightly plastic; many very fine and fine, common Bw1 horizon medium, and few coarse roots; many very fine Hue: 7.5YR or 10YR and fine interstitial pores; 15 percent cobbles and Value: 5 or 6 dry; 4 or 5 moist 35 percent pebbles; strongly acid; clear wavy Chroma: 2 to 4 or 6 boundary. Texture: Loam or sandy loam Bw1—16 to 26 inches; light brownish gray (10YR 6/2) Clay content: 10 to 25 percent extremely gravelly sandy loam, brown (10YR 5/3) Content of rock fragments: 60 to 85 percent— moist; weak fine subangular blocky structure; 25 to 40 percent stones and cobbles; 25 to slightly hard, very friable, slightly sticky, slightly 55 percent pebbles plastic; common very fine and fine and few Reaction: pH 5.1 to 6.5 Powell County Area, Montana—Part I 105
Bw2 and BC horizons 82E—Elve gravelly loam, Hue: 7.5YR or 10YR 15 to 35 percent slopes Value: 6 to 8 dry; 4 or 5 moist Chroma: 3, 4, or 6 Setting Texture: Sandy loam or loam Clay content: 5 to 20 percent Landform: Hills Content of rock fragments: 60 to 85 percent— Slope: 15 to 35 percent 20 to 40 percent stones and cobbles; 35 to Elevation: 4,400 to 7,500 feet 65 percent pebbles Mean annual precipitation: 20 to 30 inches Reaction: pH 5.1 to 6.5 Frost-free period: 30 to 70 days Composition 82D—Elve gravelly loam, Major Components 4 to 15 percent slopes Elve and similar soils: 85 percent Minor Components Setting Areas of rock outcrop: 0 to 8 percent Landform: Hills Soils that are clayey below 12 inches: 0 to 7 percent Slope: 4 to 15 percent Major Component Description Elevation: 4,400 to 7,500 feet Mean annual precipitation: 20 to 30 inches Surface layer texture: Gravelly loam Frost-free period: 30 to 70 days Depth class: Very deep (more than 60 inches) Drainage class: Somewhat excessively drained Composition Dominant parent material: Colluvium Major Components Native plant cover type: Forestland Elve and similar soils: 85 percent Flooding: None Available water capacity: Mainly 4.5 inches Minor Components Areas of rock outcrop: 0 to 8 percent A typical soil description with range in Soils that are very gravelly below 10 inches: 0 to characteristics is included, in alphabetical order, in 7 percent this section. Major Component Description Management Surface layer texture: Gravelly loam For management information about this map unit, Depth class: Very deep (more than 60 inches) see appropriate sections in Part II of this publication. Drainage class: Somewhat excessively drained Dominant parent material: Colluvium Native plant cover type: Forestland Flooding: None 82F—Elve gravelly loam, Available water capacity: Mainly 4.5 inches 35 to 60 percent slopes
A typical soil description with range in Setting characteristics is included, in alphabetical order, in this section. Landform: Hills Slope: 35 to 60 percent Management Elevation: 4,400 to 7,500 feet For management information about this map unit, Mean annual precipitation: 20 to 30 inches see appropriate sections in Part II of this publication. Frost-free period: 30 to 70 days 106 Soil Survey
Composition A typical soil description with range in characteristics is included, in alphabetical order, in Major Components this section. Elve and similar soils: 85 percent Management Minor Components Areas of rock outcrop: 0 to 8 percent For management information about this map unit, Soils that are clayey below 12 inches: 0 to 7 percent see appropriate sections in Part II of this publication. Major Component Description Surface layer texture: Gravelly loam 382E—Elve gravelly loam, warm, Depth class: Very deep (more than 60 inches) 15 to 35 percent slopes Drainage class: Somewhat excessively drained Dominant parent material: Colluvium Setting Native plant cover type: Forestland Landform: Mountains Flooding: None Slope: 15 to 35 percent Available water capacity: Mainly 4.5 inches Elevation: 4,400 to 7,500 feet Mean annual precipitation: 20 to 30 inches A typical soil description with range in Frost-free period: 30 to 70 days characteristics is included, in alphabetical order, in this section. Composition Management Major Components Elve and similar soils: 85 percent For management information about this map unit, see appropriate sections in Part II of this publication. Minor Components Very gravelly sandy soils: 0 to 5 percent Soils that have slopes more than 35 percent: 0 to 382D—Elve gravelly loam, warm, 5 percent 8 to 15 percent slopes Evaro soils: 0 to 5 percent Major Component Description Setting Surface layer texture: Gravelly loam Landform: Mountains Depth class: Very deep (more than 60 inches) Slope: 8 to 15 percent Drainage class: Somewhat excessively drained Elevation: 4,400 to 7,500 feet Dominant parent material: Colluvium Mean annual precipitation: 20 to 30 inches Native plant cover type: Forestland Frost-free period: 30 to 70 days Flooding: None Available water capacity: Mainly 4.5 inches Composition Major Components A typical soil description with range in Elve and similar soils: 85 percent characteristics is included, in alphabetical order, in this section. Minor Components Very gravelly sandy soils: 0 to 5 percent Management Soils that have slopes more than 15 percent: 0 to For management information about this map unit, 5 percent see appropriate sections in Part II of this publication. Evaro soils: 0 to 5 percent Major Component Description Surface layer texture: Gravelly loam 382F—Elve gravelly loam, warm, Depth class: Very deep (more than 60 inches) 35 to 60 percent slopes Drainage class: Somewhat excessively drained Dominant parent material: Colluvium Setting Native plant cover type: Forestland Flooding: None Landform: Mountains Available water capacity: Mainly 4.5 inches Slope: 35 to 60 percent Powell County Area, Montana—Part I 107
Elevation: 4,400 to 7,500 feet Major Component Description Mean annual precipitation: 20 to 30 inches Surface layer texture: Gravelly loam Frost-free period: 30 to 70 days Depth class: Very deep (more than 60 inches) Drainage class: Somewhat excessively drained Composition Dominant parent material: Colluvium Major Components Native plant cover type: Forestland Elve and similar soils: 85 percent Flooding: None Available water capacity: Mainly 4.5 inches Minor Components Soils that are moderately deep: 0 to 5 percent A typical soil description with range in Very gravelly sandy soils: 0 to 4 percent characteristics is included, in alphabetical order, in Evaro soils: 0 to 3 percent this section. Soils that have slopes more than 60 percent: 0 to 3 percent Management Major Component Description For management information about this map unit, see appropriate sections in Part II of this publication. Surface layer texture: Gravelly loam Depth class: Very deep (more than 60 inches) Drainage class: Somewhat excessively drained Dominant parent material: Colluvium 482F—Elve gravelly loam, dry, Native plant cover type: Forestland 35 to 60 percent slopes Flooding: None Available water capacity: Mainly 4.5 inches Setting A typical soil description with range in Landform: Hills characteristics is included, in alphabetical order, in Slope: 35 to 60 percent this section. Elevation: 4,400 to 7,500 feet Mean annual precipitation: 20 to 30 inches Management Frost-free period: 30 to 70 days For management information about this map unit, Composition see appropriate sections in Part II of this publication. Major Components Elve and similar soils: 85 percent 482E—Elve gravelly loam, dry, 15 to 35 percent slopes Minor Components Areas of rock outcrop: 0 to 8 percent Loberg soils: 0 to 7 percent Setting Landform: Hills Major Component Description Slope: 15 to 35 percent Surface layer texture: Gravelly loam Elevation: 4,400 to 7,500 feet Depth class: Very deep (more than 60 inches) Mean annual precipitation: 20 to 30 inches Drainage class: Somewhat excessively drained Frost-free period: 30 to 70 days Dominant parent material: Colluvium Composition Native plant cover type: Forestland Flooding: None Major Components Available water capacity: Mainly 4.5 inches Elve and similar soils: 85 percent Minor Components A typical soil description with range in Areas of rock outcrop: 0 to 8 percent characteristics is included, in alphabetical order, in Loberg soils: 0 to 7 percent this section. 108 Soil Survey
Management Minor Components Very gravelly sandy soils: 0 to 15 percent For management information about this map unit, see appropriate sections in Part II of this publication. Major Component Description
682E—Elve bouldery sandy loam, Surface layer texture: Bouldery sandy loam 8 to 25 percent slopes Depth class: Very deep (more than 60 inches) Drainage class: Somewhat excessively drained Dominant parent material: Alpine till Setting Native plant cover type: Forestland Landform: Moraines Flooding: None Slope: 8 to 25 percent Available water capacity: Mainly 4.0 inches Elevation: 4,400 to 7,500 feet Mean annual precipitation: 20 to 30 inches A typical soil description with range in Frost-free period: 30 to 70 days characteristics is included, in alphabetical order, in this section. Composition Management Major Components Elve and similar soils: 85 percent For management information about this map unit, see appropriate sections in Part II of this publication. Minor Components Loberg soils: 0 to 8 percent Very gravelly sandy soils: 0 to 7 percent 982F—Elve-Rock outcrop complex, Major Component Description 35 to 60 percent slopes Surface layer texture: Bouldery sandy loam Depth class: Very deep (more than 60 inches) Setting Drainage class: Somewhat excessively drained Dominant parent material: Alpine till Landform: Native plant cover type: Forestland • Elve—Hills Flooding: None • Rock outcrop—Hills Available water capacity: Mainly 4.0 inches Slope: 35 to 60 percent Elevation: 4,400 to 7,500 feet A typical soil description with range in Mean annual precipitation: 20 to 30 inches characteristics is included, in alphabetical order, in Frost-free period: 30 to 70 days this section. Composition Management Major Components For management information about this map unit, Elve and similar soils: 50 percent see appropriate sections in Part II of this publication. Rock outcrop: 35 percent Minor Components 682F—Elve bouldery sandy loam, Soils that are moderately deep: 0 to 4 percent 25 to 50 percent slopes Whitore soils: 0 to 4 percent Tigeron soils: 0 to 4 percent Evaro soils: 0 to 3 percent Setting Major Component Description Landform: Moraines Slope: 25 to 50 percent Elve Elevation: 4,400 to 7,500 feet Surface layer texture: Gravelly loam Mean annual precipitation: 20 to 30 inches Depth class: Very deep (more than 60 inches) Frost-free period: 30 to 70 days Drainage class: Somewhat excessively drained Dominant parent material: Colluvium Composition Native plant cover type: Forestland Major Components Flooding: None Elve and similar soils: 85 percent Available water capacity: Mainly 4.5 inches Powell County Area, Montana—Part I 109
Rock outcrop Range in Characteristics Definition: Areas of exposed bedrock Thickness of the mollic epipedon: 7 to 15 inches Clay content: 10 to 40 percent A typical soil description with range in Rock fragments in the control section: 0 to 70 percent characteristics is included, in alphabetical order, in Depth to the seasonal high water table: 0 to 24 inches this section. Management For management information about this map unit, Evaro Series see appropriate sections in Part II of this publication. Depth class: Very deep Drainage class: Somewhat excessively drained Permeability: Moderately rapid Endoaquolls Landform: Mountains Parent material: Colluvium derived from argillite and Depth class: Very deep quartzite Drainage class: Poorly or very poorly drained Slope range: 4 to 60 percent Permeability: Moderately slow, moderate, moderately Elevation range: 4,600 to 7,000 feet rapid, or rapid Annual precipitation: 22 to 30 inches Landform: Flood plains Annual air temperature: 36 to 40 degrees F Parent material: Alluvium Frost-free period: 30 to 70 days Slope range: 0 to 2 percent Elevation range: 3,600 to 5,800 feet Taxonomic Class: Loamy-skeletal, mixed, Annual precipitation: 15 to 19 inches superactive Lamellic Eutrocryepts Annual air temperature: 39 to 44 degrees F Frost-free period: 70 to 90 days Typical Pedon Evaro gravelly loam, dry, 15 to 35 percent slopes, in Taxonomic Class: Endoaquolls an area of woodland, 700 feet north and 300 feet east Representative Pedon of the southwest corner of sec. 6, T. 12 N., R. 13 W. Endoaquolls in an area of Fluvaquents-Endoaquolls Oi—2 to 0 inches; undecomposed and slightly complex, 0 to 2 percent slopes, occasionally flooded, decomposed forest litter. in a woodland area, 500 feet south and 950 feet east A—0 to 6 inches; pale brown (10YR 6/3) gravelly of the northwest corner of sec. 32, T. 16 N., R. 12 W. loam, brown (10YR 4/3) moist; moderate fine granular structure; soft, very friable, slightly sticky, Oi—2 to 0 inches; partially decomposed leaves and slightly plastic; many very fine, fine, and medium twigs. and few coarse roots; many very fine and fine A—0 to 10 inches; very dark grayish brown (10YR irregular pores; 5 percent cobbles and 25 percent 3/2) loam, dark grayish brown (10YR 4/2) dry; pebbles; ash influenced with about 50 percent moderate medium granular structure; soft, very glass; moderately acid; clear smooth boundary. friable, nonsticky, slightly plastic; many fine and 2E—6 to 21 inches; light gray (10YR 7/2) extremely few coarse roots; many very fine interstitial pores; gravelly loam, light brownish gray (10YR 6/2) neutral; clear smooth boundary. moist; weak fine subangular blocky structure; Bw—10 to 26 inches; dark grayish brown (10YR 5/2) slightly hard, friable, nonsticky, slightly plastic; loam, light brownish gray (10YR 6/2) dry; few fine common very fine and fine and few medium and distinct brownish yellow (10YR 6/8) redox coarse roots; many very fine and fine irregular concentrations; weak fine subangular blocky pores; 10 percent cobbles and 50 percent structure; slightly hard, friable, slightly sticky, pebbles; slightly acid; gradual wavy boundary. slightly plastic; few very fine and fine roots; many 2E and Bt1—21 to 40 inches; 75 percent is very pale very fine tubular pores; neutral; clear smooth brown (10YR 7/3) extremely gravelly loam, pale boundary. brown (10YR 6/3) moist (E part); 25 percent is Cg—26 to 60 inches; light gray (N 7/) stratified very pale brown (10YR 6/3) extremely gravelly loam 1 1 gravelly sandy loam and very gravelly loamy lamellae /16- to /4-inch thick, yellowish brown sand, light gray (5Y 7/1) dry; single grain; loose, (10YR 5/4) moist (B part); weak fine subangular slightly sticky, nonplastic; common very fine roots; blocky structure; slightly hard, friable, nonsticky, few very fine interstitial pores; neutral. slightly plastic; few very fine and fine roots; many 110 Soil Survey
very fine and fine irregular pores; 5 percent 97D—Evaro gravelly loam, dry, cobbles and 65 percent pebbles; neutral; gradual 4 to 15 percent slopes wavy boundary. 2E and Bt2—40 to 60 inches; 80 percent is very pale Setting brown (10YR 7/3) extremely gravelly sandy loam, pale brown (10YR 6/3) moist (E part); 20 percent Landform: Mountains is pale brown (10YR 6/3) extremely gravelly loam Slope: 4 to 15 percent 1 1 lamellae /16- to /4-inch thick, brown (10YR 5/3) Elevation: 4,600 to 7,000 feet moist (B part); weak fine subangular blocky Mean annual precipitation: 22 to 30 inches structure; soft, very friable, nonsticky, nonplastic; Frost-free period: 30 to 70 days few very fine and fine roots; many very fine and Composition fine irregular pores; 5 percent cobbles and 65 percent pebbles; neutral. Major Components Evaro and similar soils: 85 percent Range in Characteristics Minor Components Soil temperature: 39 to 44 degrees F Worock soils: 0 to 5 percent Moisture control section: Between depths of 8 and Soils that have slopes more than 15 percent: 0 to 24 inches 5 percent Other features: Moist bulk density is less than Loberg soils: 0 to 5 percent 0.95 g/cc to a depth of 6 inches or less and does not meet the thickness requirement for Major Component Description the vitrandic or andic intergrade. Surface layer texture: Gravelly loam A horizon Depth class: Very deep (more than 60 inches) Hue: 10YR or 7.5YR Drainage class: Somewhat excessively drained Value: 5 or 6 dry; 4 or 5 moist Dominant parent material: Colluvium Chroma: 3 or 4 Native plant cover type: Forestland Glass: 35 to 60 percent Flooding: None Clay content: 7 to 15 percent Available water capacity: Mainly 4.1 inches Content of rock fragments: 15 to 35 percent—0 to 10 percent cobbles; 15 to 25 percent pebbles A typical soil description with range in Reaction: pH 5.6 to 6.5 characteristics is included, in alphabetical order, in 2E horizon this section. Hue: 10YR or 7.5YR Management Value: 6 to 8 dry; 5 to 7 moist Chroma: 2 or 3 For management information about this map unit, Texture: Loam or sandy loam see appropriate sections in Part II of this publication. Clay content: 5 to 15 percent Content of rock fragments: 40 to 80 percent—5 to 30 percent cobbles; 35 to 50 percent pebbles 97E—Evaro gravelly loam, dry, Reaction: pH 5.6 to 7.3 15 to 35 percent slopes 2E and Bt horizons Hue: E part—10YR or 7.5YR; B part—10YR or Setting 7.5YR Value: E part—6 or 7 dry, 4 to 6 moist; B part— Landform: Mountains 5 or 6 dry, 4 or 5 moist Slope: 15 to 35 percent Chroma: E part—2 or 3; B part—3 or 4 Elevation: 4,600 to 7,000 feet Texture: Loam or sandy loam Mean annual precipitation: 22 to 30 inches Clay content: 5 to 18 percent; lamellae have less Frost-free period: 30 to 70 days than 3 percent clay increase Composition Content of rock fragments: 60 to 80 percent—5 to 15 percent cobbles; 55 to 65 percent pebbles Major Components Reaction: pH 5.6 to 7.3 Evaro and similar soils: 85 percent Powell County Area, Montana—Part I 111
Minor Components Native plant cover type: Forestland Worock soils: 0 to 4 percent Flooding: None Soils that have slopes more than 35 percent: 0 to Available water capacity: Mainly 4.1 inches 3 percent Loberg soils: 0 to 3 percent A typical soil description with range in Areas of rock outcrop: 0 to 2 percent characteristics is included, in alphabetical order, in Areas of rubble land: 0 to 2 percent this section. Major Component Description Management Surface layer texture: Gravelly loam For management information about this map unit, Depth class: Very deep (more than 60 inches) see appropriate sections in Part II of this publication. Drainage class: Somewhat excessively drained Dominant parent material: Colluvium Native plant cover type: Forestland 197D—Evaro gravelly loam, Flooding: None 4 to 15 percent slopes Available water capacity: Mainly 4.1 inches
A typical soil description with range in Setting characteristics is included, in alphabetical order, in Landform: Mountains this section. Slope: 4 to 15 percent Management Elevation: 4,600 to 7,000 feet Mean annual precipitation: 22 to 30 inches For management information about this map unit, Frost-free period: 30 to 70 days see appropriate sections in Part II of this publication. Composition 97F—Evaro gravelly loam, dry, Major Components 35 to 60 percent slopes Evaro and similar soils: 85 percent Minor Components Setting Worock soils: 0 to 5 percent Soils that have slopes more than 15 percent: 0 to Landform: Mountains 4 percent Slope: 35 to 60 percent Loberg soils: 0 to 4 percent Elevation: 4,600 to 7,000 feet Soils that have a thick volcanic ash surface: 0 to Mean annual precipitation: 22 to 30 inches 2 percent Frost-free period: 30 to 70 days Composition Major Component Description Major Components Surface layer texture: Gravelly loam Evaro and similar soils: 85 percent Depth class: Very deep (more than 60 inches) Minor Components Drainage class: Somewhat excessively drained Worock soils: 0 to 4 percent Dominant parent material: Colluvium Soils that have slopes more than 60 percent: 0 to Native plant cover type: Forestland 3 percent Flooding: None Loberg soils: 0 to 3 percent Available water capacity: Mainly 4.1 inches Areas of rock outcrop: 0 to 2 percent Areas of rubble land: 0 to 2 percent A typical soil description with range in characteristics is included, in alphabetical order, in Major Component Description this section. Surface layer texture: Gravelly loam Management Depth class: Very deep (more than 60 inches) Drainage class: Somewhat excessively drained For management information about this map unit, Dominant parent material: Colluvium see appropriate sections in Part II of this publication. 112 Soil Survey
197E—Evaro gravelly loam, Minor Components 15 to 35 percent slopes Worock soils: 0 to 3 percent Soils that have slopes more than 60 percent: 0 to 3 percent Setting Loberg soils: 0 to 3 percent Landform: Mountains Soils that have a thick volcanic ash surface: 0 to Slope: 15 to 35 percent 3 percent Elevation: 4,600 to 7,000 feet Major Component Description Mean annual precipitation: 22 to 30 inches Frost-free period: 30 to 70 days Surface layer texture: Gravelly loam Depth class: Very deep (more than 60 inches) Composition Drainage class: Somewhat excessively drained Major Components Dominant parent material: Colluvium Evaro and similar soils: 85 percent Native plant cover type: Forestland Flooding: None Minor Components Available water capacity: Mainly 4.1 inches Worock soils: 0 to 3 percent Soils that have slopes more than 35 percent: 0 to A typical soil description with range in 3 percent characteristics is included, in alphabetical order, in Loberg soils: 0 to 3 percent this section. Soils that have a thick volcanic ash surface: 0 to 3 percent Management Major Component Description For management information about this map unit, see appropriate sections in Part II of this publication. Surface layer texture: Gravelly loam Depth class: Very deep (more than 60 inches) Drainage class: Somewhat excessively drained Fergus Series Dominant parent material: Colluvium Native plant cover type: Forestland Depth class: Very deep Flooding: None Drainage class: Well drained Available water capacity: Mainly 4.1 inches Permeability: Moderately slow Landform: Moraines A typical soil description with range in Parent material: Alpine till characteristics is included, in alphabetical order, in Slope range: 2 to 8 percent this section. Elevation range: 3,800 to 4,400 feet Annual precipitation: 15 to 19 inches Management Annual air temperature: 40 to 45 degrees F For management information about this map unit, Frost-free period: 70 to 90 days see appropriate sections in Part II of this publication. Taxonomic Class: Fine, smectitic, frigid Vertic Argiustolls 197F—Evaro gravelly loam, 35 to 60 percent slopes Typical Pedon Fergus clay loam, in an area of Fergus-Water Setting complex, 2 to 8 percent slopes, in an area of cropland, 1,400 feet north and 650 feet west of the Landform: Mountains southeast corner of sec. 1, T. 13 N., R. 12 W. Slope: 35 to 60 percent Elevation: 4,600 to 7,000 feet Ap—0 to 4 inches; brown (7.5YR 5/2) clay loam, dark Mean annual precipitation: 22 to 30 inches brown (7.5YR 3/2) moist; moderate medium Frost-free period: 30 to 70 days granular structure; slightly hard, friable, moderately sticky, moderately plastic; common Composition very fine and fine and few medium roots; Major Components common very fine and fine continuous interstitial Evaro and similar soils: 85 percent pores; neutral; abrupt smooth boundary. Powell County Area, Montana—Part I 113
Bt1—4 to 11 inches; reddish brown (5YR 5/3) clay, Content of rock fragments: 0 to 15 percent dark reddish brown (5YR 3/3) moist; strong pebbles coarse prismatic structure parting to moderate Reaction: pH 6.6 to 7.8 medium subangular blocky; hard, very firm, very Bt1 horizon sticky, very plastic; few very fine, fine, and Hue: 5YR, 7.5YR, or 10YR medium roots; common very fine and fine Value: 4 or 5 dry; 3 or 4 moist discontinuous irregular pores; many distinct clay Chroma: 2 or 3 films on faces of peds and lining pores; neutral; Texture: Clay loam, silty clay loam, or clay clear smooth boundary. Clay content: 35 to 50 percent Bt2—11 to 15 inches; reddish brown (5YR 5/3) clay Content of rock fragments: 0 to 15 percent loam, reddish brown (2.5YR 4/4) moist; weak pebbles medium prismatic structure parting to moderate Reaction: pH 6.6 to 7.8 medium subangular blocky; very hard, firm, very sticky, very plastic; few very fine and fine roots; Bt2 horizon common very fine and fine continuous irregular Hue: 2.5YR, 5YR, or 7.5YR pores; many distinct clay films on faces of peds Value: 4 or 5 dry; 3 or 4 moist and lining pores; slightly alkaline; clear smooth Chroma: 2 to 4 or 6 boundary. Texture: Clay loam, clay, or silty clay loam Bt3—15 to 21 inches; light reddish brown (5YR 6/3) Clay content: 35 to 50 percent clay loam, reddish brown (2.5YR 5/4) moist; Content of rock fragments: 0 to 15 percent moderate medium subangular blocky structure; pebbles very hard, friable, moderately sticky, moderately Reaction: pH 6.6 to 7.8 plastic; few very fine and fine roots; common very Bt3 horizon fine and few fine continuous irregular pores; few Hue: 2.5YR, 5YR, or 7.5YR faint clay films on faces of peds; moderately Value: 4 to 6 dry; 3 to 5 moist alkaline; gradual smooth boundary. Chroma: 2 to 4 or 6 Btk—21 to 36 inches; light reddish brown (5YR 6/3) Texture: Clay loam, clay, or silty clay loam clay loam, reddish brown (2.5YR 5/4) moist; weak Clay content: 35 to 50 percent coarse subangular blocky structure; hard, friable, Content of rock fragments: 0 to 15 percent moderately sticky, moderately plastic; few very pebbles fine and fine continuous irregular pores; few faint Reaction: pH 7.4 to 8.4 clay films on faces of peds; common very fine threads of lime; strongly effervescent; moderately Btk horizon alkaline; gradual wavy boundary. Hue: 2.5YR, 5YR, or 7.5YR Bk—36 to 60 inches; pink (5YR 7/3) clay loam, Value: 4 to 7 dry; 3 to 5 moist reddish brown (2.5YR 5/4) moist; weak fine Chroma: 2 to 4 or 6 subangular blocky structure; hard, friable, Texture: Silty clay loam, clay loam, or clay moderately sticky, moderately plastic; common Clay content: 27 to 45 percent very fine threads of lime; strongly effervescent; Content of rock fragments: 0 to 15 percent moderately alkaline. pebbles Calcium carbonate equivalent: 5 to 15 percent Range in Characteristics Reaction: pH 7.4 to 8.4 Bk horizon Soil temperature: 42 to 47 degrees F Hue: 2.5YR, 5YR, or 7.5YR Moisture control section: Between depths of 4 and Value: 4 to 7 dry; 3 to 5 moist 12 inches Chroma: 2 to 4 or 6 Thickness of the mollic epipedon: 7 to 12 inches Texture: Silty clay loam, clay loam, or clay Depth to the Bk horizon: 20 to 36 inches Clay content: 27 to 45 percent Ap horizon Content of rock fragments: 0 to 15 percent Hue: 5YR, 7.5YR, or 10YR pebbles Value: 3 to 5 dry; 2 or 3 moist Calcium carbonate equivalent: 5 to 15 percent Clay content: 27 to 35 percent Reaction: pH 7.4 to 8.4 114 Soil Survey
40C—Fergus-Water complex, Annual air temperature: 39 to 44 degrees F 2 to 8 percent slopes Frost free period: 90 to 105 days Taxonomic Class: Fluvaquentic Endoaquolls Setting Typical Pedon Landform: Moraines Fluvaquentic Endoaquolls fine sandy loam, 0 to Slope: 2 to 8 percent 2 percent slopes, in an area of Fluvaquentic Elevation: 3,800 to 4,400 feet Endoaquolls-Slickens complex, 0 to 2 percent slopes, Mean annual precipitation: 15 to 19 inches severely impacted, 1,700 feet south and 1,200 feet Frost-free period: 70 to 90 days west of the northeast corner of sec. 18, T. 5 N., Composition R. 9 W. Major Components Oi—0 to 2 inches; partially decomposed organic Fergus and similar soils: 75 percent matter. Water: 10 percent C—2 to 8 inches; strong brown (7.5YR 5/6) fine sandy loam, light yellowish brown (10YR 6/4) dry; Minor Components massive; soft, very friable, slightly sticky, slightly Soils that have very gravelly profiles: 0 to 5 percent plastic; common very fine, fine, medium and Soils that are somewhat poorly drained: 0 to coarse roots; 1 percent pebbles; very strongly 5 percent acid; abrupt smooth boundary. Soils that have slopes more than 8 percent: 0 to Ab—8 to 14 inches; very dark brown (10YR 2/2) 5 percent loam, dark grayish brown (10YR 4/2) dry; Major Component Description moderate fine granular structure; slightly hard, very friable, moderately sticky, slightly plastic; Fergus common very fine, fine, medium and coarse Surface layer texture: Clay loam roots; few very fine pores; 1 percent pebbles; Depth class: Very deep (more than 60 inches) neutral; clear wavy boundary. Drainage class: Well drained Abg—14 to 22 inches; very dark grayish brown (2.5Y Dominant parent material: Alpine till 3/2) loam, grayish brown (2.5Y 5/2) dry; few fine Native plant cover type: Rangeland distinct reddish yellow (7.5YR 6/8) redox Flooding: None concentrations; weak medium granular structure; Available water capacity: Mainly 8.6 inches hard, friable, moderately sticky, slightly plastic; common very fine and fine and few medium and Water coarse roots; common very fine and few fine Definition: Areas of open water discontinuous irregular pores; 1 percent pebbles; disseminated lime; slightly effervescent; slightly A typical soil description with range in alkaline; abrupt wavy boundary. characteristics is included, in alphabetical order, in Cb1—22 to 26 inches; dark brown (10YR 3/3) very this section. fine sandy loam, light yellowish brown (10YR 6/4) Management dry; single grain; loose, slightly sticky, nonplastic; common very fine and fine roots; 1 percent For management information about this map unit, pebbles; slightly alkaline; abrupt wavy boundary. see appropriate sections in Part II of this publication. Abg2—26 to 38 inches; very dark gray (2.5Y 3/1) silty clay loam, gray (2.5Y 5/1) dry; common coarse Fluvaquentic Endoaquolls black (N 2.5/) redox depletions; massive; very hard, firm, moderately sticky, moderately plastic; Depth class: Very deep common very fine roots; common very fine and Drainage class: Poorly drained few fine and medium discontinuous irregular Permeability: Rapid pores; 1 percent pebbles; slightly alkaline; abrupt Landform: Flood plains smooth boundary. Parent material: Alluvium Cb2—38 to 60 inches; variegated colors brown Slope range: 0 to 2 percent (10YR 5/3) coarse sand, pale brown (10YR 6/3) Elevation range: 4,600 to 5,200 feet dry; single grain; loose, nonsticky, nonplastic; Annual precipitation: 10 to 14 inches 1 percent pebbles; slightly alkaline. Powell County Area, Montana—Part I 115
Range in Characteristics Management Depth to the Cb2 horizon: 20 to 40 inches For management information about this map unit, Depth to the seasonal high water table: 12 to see appropriate sections in Part II of this publication. 24 inches
Fluvaquents 104A—Fluvaquentic Endoaquolls- Slickens complex, 0 to 2 percent Depth class: Very deep slopes, severely impacted Drainage class: Poorly and very poorly drained Permeability: Moderate, moderately slow, moderately rapid, or rapid Setting Landform: Flood plains Landform: Parent material: Alluvium • Fluvaquentic Endoaquolls—Flood plains Slope range: 0 to 2 percent • Slickens—Flood plains Elevation range: 3,600 to 5,800 feet Slope: Annual precipitation: 15 to 19 inches • Fluvaquentic Endoaquolls—0 to 2 percent Annual air temperature: 39 to 44 degrees F • Slickens—0 to 2 percent Frost-free period: 70 to 90 days Elevation: 4,600 to 5,000 feet Mean annual precipitation: 10 to 14 inches Representative Pedon Frost-free period: 90 to 105 days Fluvaquents, in an area of Fluvaquents-Endoaquolls Composition complex, 0 to 2 percent slopes, occasionally flooded, Major Components in a woodland area, 1,200 feet south and 1,000 feet Fluvaquentic Endoaquolls and similar soils: east of the northwest corner of sec. 32, T. 16 N., 75 percent R. 12 W. Slickens: 10 percent Oi—2.5 inches to 0; partially decomposed forest litter. Minor Components E—0 to 5 inches; light reddish brown (5YR 6/3) loamy Somewhat poorly drained soils: 0 to 10 percent sand, reddish brown (5YR 5/3) moist; weak fine Areas of riverwash: 0 to 5 percent and medium subangular blocky structure; loose, very friable, nonsticky, nonplastic; common very Major Component Description fine, fine, and medium roots; many very fine Fluvaquentic Endoaquolls tubular pores; moderately acid; gradual smooth Depth class: Very deep (more than 60 inches) boundary. Dominant parent material: Alluvium C1—5 to 10 inches; pink (5YR 7/3) loamy sand, Flooding: Occasional reddish brown (5YR 5/3) moist; few fine distinct Water table: Apparent brownish yellow (10YR 6/8) redox concentrations; single grain; loose, very friable, nonsticky, Slickens nonplastic; common very fine, fine, and medium Definition: Material from ore mills, commonly freshly roots; many very fine tubular pores; moderately ground rock that has undergone chemical acid; clear wavy boundary. treatment during the milling process C2—10 to 60 inches; pink (5YR 7/3) extremely Flooding: Occasional gravelly sand, reddish brown (5YR 5/3) moist; single grain; loose, nonsticky, nonplastic; few very A typical soil description with range in fine and fine roots; many very fine irregular pores; characteristics is included, in alphabetical order, in 10 percent cobbles and 60 percent pebbles; this section. slightly acid. 116 Soil Survey
Range in Characteristics Gregson Series Clay content: 5 to 40 percent Depth class: Very deep Rock fragments in the control section: 0 to 80 percent Drainage class: Somewhat poorly drained Depth to the seasonal high water table: 0 to 24 inches Permeability: Moderate to the 2C horizon, rapid below Landform: Outwash plains and flood plains 7—Fluvaquents-Endoaquolls complex, Parent material: Alluvium 0 to 2 percent slopes, Slope range: 0 to 4 percent occasionally flooded Elevation range: 4,000 to 5,200 feet Annual precipitation: 10 to 19 inches Annual air temperature: 39 to 44 degrees F Setting Frost-free period: 70 to 105 days Landform: • Fluvaquents—Flood plains Taxonomic Class: Fine-loamy over sandy or sandy- • Endoaquolls—Flood plains skeletal, mixed, superactive, frigid Aquic Slope: Haplustolls • Fluvaquents—0 to 2 percent Typical Pedon • Endoaquolls—0 to 2 percent Elevation: 3,600 to 5,800 feet Gregson loam, 0 to 4 percent slopes, in an area of Mean annual precipitation: 15 to 19 inches pasture, 400 feet south and 2,200 feet east of the Frost-free period: 70 to 90 days northwest corner of sec. 16, T. 6 N., R. 9 W. Composition Oe—1 inch to 0; partially decomposed organic matter. Major Components A—0 to 8 inches; very dark grayish brown (10YR 3/2) Fluvaquents and similar soils: 45 percent loam, black (10YR 2/1) moist; strong fine granular Endoaquolls and similar soils: 40 percent structure; slightly hard, friable, slightly sticky, Minor Components slightly plastic; many very fine and fine roots; Somewhat poorly drained soils: 0 to 5 percent many very fine and fine pores; slightly alkaline; Areas of open water: 0 to 5 percent clear smooth boundary. Areas of riverwash: 0 to 5 percent Bw1—8 to 18 inches; light gray (10YR 7/2) loam, grayish brown (10YR 5/2) moist; moderate fine Major Component Description granular structure; slightly hard, very friable, Fluvaquents slightly sticky, slightly plastic; common very fine Depth class: Very deep (more than 60 inches) and fine roots; many very fine and fine pores; Dominant parent material: Alluvium neutral; clear smooth boundary. Native plant cover type: Forestland Bw2—18 to 22 inches; light gray (10YR 7/2) loam, Flooding: Occasional grayish brown (10YR 5/2) moist; few fine faint Water table: Apparent strong brown (7.5YR 4/6) redox concentrations; moderate fine granular structure; slightly hard, Endoaquolls very friable, slightly sticky, slightly plastic; Depth class: Very deep (more than 60 inches) common very fine and fine roots; many very fine Dominant parent material: Alluvium and fine pores; neutral; clear smooth boundary. Native plant cover type: Forestland 2C—22 to 60 inches; light gray (10YR 7/1) very Flooding: Occasional gravelly loamy sand, grayish brown (10YR 5/2) Water table: Apparent moist; single grain; loose, nonsticky, nonplastic; few very fine and fine roots; common very fine A typical soil description with range in pores; 10 percent cobbles and 40 percent characteristics is included, in alphabetical order, in pebbles; neutral. this section. Range in Characteristics Management Soil temperature: 41 to 46 degrees F For management information about this map unit, Moisture control section: Between depths of 4 and see appropriate sections in Part II of this publication. 12 inches Powell County Area, Montana—Part I 117
Thickness of the mollic epipedon: 7 to 14 inches A typical soil description with range in Depth to the seasonal high water table: 24 to characteristics is included, in alphabetical order, in 42 inches this section. Depth to sand and gravel: 20 to 40 inches Management A horizon For management information about this map unit, Value: 2 or 3 moist; 3 to 5 dry see appropriate sections in Part II of this publication. Chroma: 1 or 2 Clay content: 18 to 27 percent Reaction: pH 6.6 to 7.8 444—Gregson loam, 0 to 4 percent Bw horizons slopes, rarely flooded Value: 4 to 6 moist; 6 or 7 dry Chroma: 2 or 3 Setting Texture: Loam or clay loam Landform: Flood plains Clay content: 18 to 35 percent Slope: 0 to 4 percent Reaction: pH 6.6 to 7.8 Elevation: 4,000 to 5,000 feet 2C horizon Mean annual precipitation: 10 to 14 inches Value: 5 or 6 moist; 6 or 7 dry Frost-free period: 90 to 105 days Chroma: 1 or 2 Composition Texture: Loamy sand or sand Clay content: 0 to 5 percent Major Components Content of rock fragments: 35 to 60 percent—5 to Gregson and similar soils: 85 percent 15 percent cobbles; 30 to 45 percent pebbles Minor Components Reaction: pH 6.6 to 7.8 Very gravelly sandy soils: 0 to 5 percent Poorly drained soils: 0 to 5 percent 434—Gregson loam, cool, 0 to 4 percent Gregson very cobbly loam: 0 to 5 percent slopes, rarely flooded Major Component Description Surface layer texture: Loam Setting Depth class: Very deep (more than 60 inches) Landform: Flood plains Drainage class: Somewhat poorly drained Slope: 0 to 4 percent Dominant parent material: Alluvium Elevation: 4,000 to 5,200 feet Native plant cover type: Rangeland Mean annual precipitation: 15 to 19 inches Flooding: Rare Frost-free period: 70 to 90 days Water table: Apparent Available water capacity: Mainly 5.9 inches Composition Major Components A typical soil description with range in Gregson and similar soils: 85 percent characteristics is included, in alphabetical order, in this section. Minor Components Very gravely sandy soils: 0 to 5 percent Management Poorly drained soils: 0 to 5 percent For management information about this map unit, Soils that have a cobbly loam surface: 0 to 5 percent see appropriate sections in Part II of this publication. Major Component Description Surface layer texture: Loam 534—Gregson loam, cool, Depth class: Very deep (more than 60 inches) 0 to 4 percent slopes Drainage class: Somewhat poorly drained Dominant parent material: Alluvium Setting Native plant cover type: Rangeland Flooding: Rare Landform: Outwash plains Water table: Apparent Slope: 0 to 4 percent Available water capacity: Mainly 5.9 inches Elevation: 4,000 to 5,200 feet 118 Soil Survey
Mean annual precipitation: 15 to 19 inches Native plant cover type: Rangeland Frost-free period: 70 to 90 days Flooding: None Water table: Apparent Composition Available water capacity: Mainly 5.9 inches Major Components Gregson and similar soils: 85 percent A typical soil description with range in characteristics is included, in alphabetical order, in Minor Components this section. Soils that are very gravelly below 10 inches: 0 to 8 percent Management Poorly drained soils: 0 to 7 percent For management information about this map unit, Major Component Description see appropriate sections in Part II of this publication. Surface layer texture: Loam Depth class: Very deep (more than 60 inches) Drainage class: Somewhat poorly drained Helmville Series Dominant parent material: Alluvium Depth class: Very deep Native plant cover type: Rangeland Drainage class: Well drained Flooding: None Permeability: Moderately slow Water table: Apparent Landform: Mountains Available water capacity: Mainly 5.9 inches Parent material: Colluvium from limestone and argillite A typical soil description with range in Slope range: 8 to 60 percent characteristics is included, in alphabetical order, in Elevation range: 4,600 to 7,500 feet this section. Annual precipitation: 20 to 30 inches Management Annual air temperature: 35 to 38 degrees F Frost-free period: 30 to 70 days For management information about this map unit, see appropriate sections in Part II of this publication. Taxonomic Class: Loamy-skeletal, mixed, superactive Eutric Haplocryalfs 544—Gregson loam, 0 to 4 percent slopes Typical Pedon Helmville cobbly loam, 15 to 35 percent slopes, in an Setting area of woodland, 350 feet south and 2,300 feet west Landform: Outwash plains of the northeast corner of sec. 5, T. 11 N., R. 11 W. Slope: 0 to 4 percent Oi—2 inches to 0; partly decomposed organic matter. Elevation: 4,000 to 5,000 feet E—0 to 5 inches; pinkish gray (7.5YR 6/2) cobbly Mean annual precipitation: 10 to 14 inches loam, brown (7.5YR 4/2) moist; weak fine Frost-free period: 90 to 105 days subangular blocky structure; soft, friable, slightly Composition sticky, slightly plastic; many very fine and fine and common medium and coarse roots; many very Major Components fine and fine interstitial pores; 10 percent cobbles Gregson and similar soils: 85 percent and 15 percent pebbles; neutral; clear smooth Minor Components boundary. Soils that are very gravelly below 10 inches: 0 to Bt1—5 to 13 inches; light brown (7.5YR 6/4) very 5 percent gravelly clay loam, dark brown (7.5YR 4/4) moist; Poorly drained soils: 0 to 5 percent strong coarse subangular blocky structure; hard, Soils that have a cobbly loam surface: 0 to 5 percent firm, moderately sticky and moderately plastic; many very fine and fine and common medium Major Component Description and coarse roots; common distinct clay films on Surface layer texture: Loam faces of peds; 15 percent cobbles and 35 percent Depth class: Very deep (more than 60 inches) pebbles; neutral; clear wavy boundary. Drainage class: Somewhat poorly drained Bt2—13 to 22 inches; light yellowish brown (10YR Dominant parent material: Alluvium 6/4) very gravelly clay loam, dark yellowish brown Powell County Area, Montana—Part I 119
(10YR 4/4) moist; moderate medium subangular Chroma: 3, 4, or 6 blocky structure; slightly hard, friable, slightly Texture: Loam, sandy loam, or clay loam sticky, slightly plastic; common very fine and fine Clay content: 18 to 30 percent and few medium and coarse roots; common very Rock fragments, flat or subrounded: 40 to fine and fine interstitial pores; common distinct 90 percent—15 to 45 percent stones and clay films on faces of peds; 15 percent cobbles cobbles; 20 to 45 percent pebbles or channers and 40 percent pebbles; strongly effervescent; Calcium carbonate equivalent: 15 to 30 percent slightly alkaline; gradual wavy boundary. Reaction: pH 7.4 to 8.4 Bk—22 to 60 inches; light yellowish brown (10YR 6/4) very gravelly loam, yellowish brown (10YR 5/4) moist; moderate fine subangular blocky structure; 84D—Helmville cobbly loam, slightly hard, friable, slightly sticky, slightly plastic; 8 to 15 percent slopes few very fine, fine, and medium roots; few very fine interstitial pores; 15 percent cobbles and 45 percent pebbles; disseminated lime; violently Setting effervescent; slightly alkaline. Landform: Mountains Range in Characteristics Slope: 8 to 15 percent Elevation: 4,600 to 7,000 feet Soil temperature: 37 to 42 degrees F Mean annual precipitation: 20 to 30 inches Moisture control section: Between depths of 4 and Frost-free period: 30 to 70 days 12 inches Depth to accumulation of carbonates: 15 to 40 inches Composition E horizon Major Components Hue: 10YR or 7.5YR Helmville and similar soils: 85 percent Value: 5 to 7 dry; 3 to 5 moist Minor Components Chroma: 2 to 4 Areas of rock outcrop: 0 to 8 percent Clay content: 18 to 27 percent Danaher soils: 0 to 7 percent Rock fragments, flat or subrounded: 15 to 35 percent—0 to 20 percent stones, Major Component Description flagstones, and cobbles; 5 to 30 percent Surface layer texture: Cobbly loam pebbles or channers Depth class: Very deep (more than 60 inches) Reaction: pH 5.6 to 7.3 Drainage class: Well drained Bt1 horizon Dominant parent material: Colluvium Hue: 10YR or 7.5YR Native plant cover type: Forestland Value: 4 to 6 dry; 3 to 5 moist Flooding: None Chroma: 4 or 6 Available water capacity: Mainly 5.5 inches Clay content: 27 to 35 percent Rock fragments, flat or subrounded: 30 to A typical soil description with range in 60 percent—10 to 35 percent stones and characteristics is included, in alphabetical order, in cobbles; 15 to 50 percent pebbles or channers this section. Reaction: pH 6.1 to 7.8 Management Bt2 horizon For management information about this map unit, Hue: 10YR or 7.5YR see appropriate sections in Part II of this publication. Value: 4 to 6 dry; 3 to 5 moist Chroma: 4 or 6 Clay content: 27 to 35 percent Rock fragments, flat or subrounded: 35 to 84E—Helmville cobbly loam, 60 percent—10 to 35 percent stones and 15 to 35 percent slopes cobbles; 15 to 50 percent pebbles or channers Reaction: pH 6.1 to 7.8 Setting Bk horizon Landform: Mountains Hue: 10YR or 2.5Y Slope: 15 to 35 percent Value: 5 to 7 dry; 4 or 5 moist Elevation: 4,600 to 7,000 feet 120 Soil Survey
Mean annual precipitation: 20 to 30 inches A typical soil description with range in Frost-free period: 30 to 70 days characteristics is included, in alphabetical order, in this section. Composition Management Major Components Helmville and similar soils: 85 percent For management information about this map unit, see appropriate sections in Part II of this publication. Minor Components Areas of rock outcrop: 0 to 8 percent Danaher soils: 0 to 7 percent 184E—Helmville cobbly loam, moist, Major Component Description 15 to 35 percent slopes Surface layer texture: Cobbly loam Depth class: Very deep (more than 60 inches) Setting Drainage class: Well drained Landform: Mountains Dominant parent material: Colluvium Slope: 15 to 35 percent Native plant cover type: Forestland Elevation: 4,600 to 7,000 feet Flooding: None Mean annual precipitation: 20 to 30 inches Available water capacity: Mainly 5.5 inches Frost-free period: 30 to 70 days A typical soil description with range in Composition characteristics is included, in alphabetical order, in Major Components this section. Helmville and similar soils: 85 percent Management Minor Components For management information about this map unit, Relyea soils: 0 to 5 percent see appropriate sections in Part II of this publication. Soils that have slopes more than 35 percent: 0 to 5 percent Danaher soils: 0 to 5 percent 84F—Helmville cobbly loam, Major Component Description 35 to 60 percent slopes Surface layer texture: Cobbly loam Depth class: Very deep (more than 60 inches) Setting Drainage class: Well drained Dominant parent material: Colluvium Landform: Mountains Native plant cover type: Forestland Slope: 35 to 60 percent Flooding: None Elevation: 4,600 to 7,000 feet Available water capacity: Mainly 5.5 inches Mean annual precipitation: 20 to 30 inches Frost-free period: 30 to 70 days A typical soil description with range in Composition characteristics is included, in alphabetical order, in this section. Major Components Helmville and similar soils: 85 percent Management Minor Components For management information about this map unit, Areas of rock outcrop: 0 to 15 percent see appropriate sections in Part II of this publication. Major Component Description Surface layer texture: Cobbly loam 184F—Helmville cobbly loam, moist, Depth class: Very deep (more than 60 inches) 35 to 60 percent slopes Drainage class: Well drained Dominant parent material: Colluvium Setting Native plant cover type: Forestland Flooding: None Landform: Mountains Available water capacity: Mainly 5.5 inches Slope: 35 to 60 percent Powell County Area, Montana—Part I 121
Elevation: 4,600 to 7,000 feet A1—0 to 6 inches; grayish brown (10YR 5/2) loam, Mean annual precipitation: 20 to 30 inches dark brown (10YR 3/3) moist; weak fine granular Frost-free period: 30 to 70 days structure; soft, very friable, slightly sticky, slightly plastic; many fine and medium roots; common Composition very fine irregular pores; neutral; clear smooth Major Components boundary. Helmville and similar soils: 85 percent A2—6 to 12 inches; pale brown (10YR 6/3) gravelly loam, dark brown (10YR 3/3) moist; moderate Minor Components fine granular structure; soft, very friable, slightly Relyea soils: 0 to 5 percent sticky, slightly plastic; many fine and medium Soils that have slopes more than 60 percent: 0 to roots; many very fine tubular pores; common 5 percent skeletans of light brownish gray (10YR 6/2) Danaher soils: 0 to 5 percent unstained sand and silt grains; 15 percent Major Component Description pebbles; neutral; clear wavy boundary. Bt1—12 to 23 inches; yellowish brown (10YR 5/4) Surface layer texture: Cobbly loam gravelly sandy clay loam, brown (10YR 4/3) Depth class: Very deep (more than 60 inches) moist; moderate medium subangular blocky Drainage class: Well drained structure; hard, firm, moderately sticky and Dominant parent material: Colluvium moderately plastic; common fine and medium Native plant cover type: Forestland roots; many very fine tubular pores; common faint Flooding: None clay films on faces of peds; 5 percent cobbles Available water capacity: Mainly 5.5 inches and 15 percent pebbles; neutral; clear wavy boundary. A typical soil description with range in Bt2—23 to 37 inches; light olive brown (2.5Y 5/4) characteristics is included, in alphabetical order, in gravelly sandy clay loam, olive brown (2.5Y 4/4) this section. moist; moderate medium subangular blocky Management structure; hard, firm, moderately sticky and moderately plastic; common very fine and few For management information about this map unit, medium roots; many very fine tubular pores; see appropriate sections in Part II of this publication. common distinct clay films on faces of peds; 5 percent cobbles and 15 percent pebbles; Hoyt Series slightly alkaline; clear wavy boundary. BC—37 to 60 inches; yellowish brown (2.5Y 5/4) Depth class: Very deep gravelly coarse sandy loam, olive brown (2.5Y Drainage class: Well drained 4/4) moist; massive; soft, friable, slightly sticky, Permeability: Moderate nonplastic; few fine and medium roots; common Landform: Mountains very fine irregular pores; 5 percent cobbles and Parent material: Colluvium derived from igneous rock 15 percent pebbles; slightly alkaline. and till Range in Characteristics Slope range: 8 to 35 percent Elevation range: 4,400 to 6,200 feet Soil temperature: 41 to 47 degrees F Annual precipitation: 18 to 24 inches Moisture control section: Between depths of 4 and Annual air temperature: 39 to 45 degrees F 12 inches; the soils are frozen in the moisture Frost-free period: 70 to 90 days control section and deeper from approximately November through the end of March; they are Taxonomic Class: Fine-loamy, mixed, superactive, moist in some or all parts of the moisture control frigid Typic Haplustalfs section from April through mid July Other features: The surface, when mixed to 7 inches, Typical Pedon has mollic colors but does not meet the thickness Hoyt loam, 15 to 35 percent slopes, in an area of requirements for a mollic epipedon. woodland, 2,800 feet south and 1,500 feet east of A1 horizon the northwest corner of sec. 2, T. 10 N., R. 11 W. Value: 4 or 5 dry; 2 or 3 moist Oi—1 inch to 0; partially decomposed twigs and Chroma: 2 or 3 needles. Clay content: 18 to 27 percent 122 Soil Survey
Content of rock fragments: 0 to 15 percent—0 to Minor Components 5 percent cobbles; 0 to 10 percent pebbles Yreka soils: 0 to 8 percent Reaction: pH 6.6 to 7.8 Soils that have slopes more than 15 percent: 0 to 7 percent A2 horizon Value: 2 to 4 moist Major Component Description Chroma: 2 or 3 Surface layer texture: Loam Clay content: 10 to 27 percent Depth class: Very deep (more than 60 inches) Content of rock fragments: 0 to 20 percent—0 to Drainage class: Well drained 5 percent cobbles; 0 to 15 percent pebbles Dominant parent material: Colluvium Reaction: pH 6.6 to 7.8 Native plant cover type: Forestland Bt1 horizon Flooding: None Hue: 2.5Y, 10YR, or 7.5YR Available water capacity: Mainly 8.4 inches Value: 4 to 6 dry; 3 or 4 moist Chroma: 3 or 4 A typical soil description with range in Texture: Clay loam, sandy clay loam, or loam characteristics is included, in alphabetical order, in Clay content: 18 to 35 percent this section. Content of rock fragments: 15 to 35 percent—0 to Management 5 percent cobbles; 15 to 30 percent pebbles Reaction: pH 6.6 to 7.8 For management information about this map unit, see appropriate sections in Part II of this publication. Bt2 horizon Hue: 2.5Y, 10YR, or 7.5YR Value: 4 or 5 dry; 3 or 4 moist Texture: Clay loam, sandy clay loam, or loam 452E—Hoyt loam, 15 to 35 percent slopes Clay content: 18 to 35 percent Content of rock fragments: 15 to 35 percent—0 to Setting 5 percent cobbles; 15 to 30 percent pebbles Landform: Mountains Reaction: pH 6.6 to 7.8 Slope: 15 to 35 percent BC horizon Elevation: 4,400 to 6,200 feet Hue: 2.5Y or 10YR Mean annual precipitation: 18 to 24 inches Value: 5 or 6 dry; 4 or 5 moist Frost-free period: 70 to 90 days Chroma: 2 to 4 Composition Texture: Coarse loamy sand, coarse sandy loam, or clay loam Major Components Clay content: 10 to 30 percent Hoyt and similar soils: 85 percent Content of rock fragments: 15 to 35 percent—0 to Minor Components 5 percent cobbles; 15 to 30 percent pebbles Yreka soils: 0 to 8 percent Reaction: pH 6.6 to 7.8 Soils that have slopes more than 35 percent: 0 to 7 percent 452D—Hoyt loam, 8 to 15 percent slopes Major Component Description Surface layer texture: Loam Setting Depth class: Very deep (more than 60 inches) Landform: Mountains Drainage class: Well drained Slope: 8 to 15 percent Dominant parent material: Colluvium Elevation: 4,400 to 6,200 feet Native plant cover type: Forestland Mean annual precipitation: 18 to 24 inches Flooding: None Frost-free period: 70 to 90 days Available water capacity: Mainly 7.7 inches Composition A typical soil description with range in Major Components characteristics is included, in alphabetical order, in Hoyt and similar soils: 85 percent this section. Powell County Area, Montana—Part I 123
Management redox concentrations; weak fine and medium subangular blocky structure; soft, very friable, For management information about this map unit, slightly sticky, slightly plastic; common very fine, see appropriate sections in Part II of this publication. many fine, and few coarse roots; many very fine and fine pores; 10 percent cobbles and Kleinschmidt Series 40 percent pebbles; few thin lime casts on underside of coarse fragments; slightly alkaline; Depth class: Very deep clear wavy boundary. Drainage class: Somewhat poorly drained 2Bk—37 to 60 inches; brown (10YR 5/3) extremely Permeability: Moderate cobbly loamy sand, dark brown (10YR 4/3) moist; Landform: Alluvial fans and stream terraces single grain; loose, nonsticky, nonplastic; few very Parent material: Alluvium fine and fine roots; 35 percent cobbles and 35 Slope range: 0 to 4 percent percent pebbles; disseminated lime; slightly Elevation range: 3,800 to 5,800 feet effervescent; moderately alkaline. Annual precipitation: 10 to 19 inches Annual air temperature: 39 to 44 degrees F Range in Characteristics Frost-free period: 70 to 105 days Soil temperature: 41 to 46 degrees F Moisture control section: Between depths of 4 and Taxonomic Class: Loamy-skeletal, mixed, 12 inches superactive, frigid Oxyaquic Haplustolls Thickness of the mollic epipedon: 7 to 15 inches Typical Pedon Depth to the seasonal high water table: 24 to 42 inches Kleinschmidt gravelly loam, cool, 0 to 4 percent Depth to the 2Bk horizon: 30 to 48 inches slopes, in an area of hayland, 2,600 feet south and 2,200 feet west of the northeast corner of sec. 34, Ap horizon T. 14 N., R. 11 W. Value: 2 or 3 moist; 3 to 5 dry Chroma: 1 or 2 Ap—0 to 7 inches; dark grayish brown (10YR 4/2) Clay content: 15 to 25 percent gravelly loam, black (10YR 2/1) moist; moderate Content of rock fragments: 15 to 35 percent—0 to fine granular structure; slightly hard, friable, 5 percent cobbles; 15 to 30 percent pebbles slightly sticky, moderately plastic; many very fine Reaction: pH 6.6 to 7.8 and fine and few medium roots; many very fine and fine pores; 25 percent pebbles; neutral; A horizon abrupt smooth boundary. Hue: 10YR or 7.5YR A—7 to 14 inches; dark grayish brown (10YR 4/2) Value: 2 to 4 moist; 4 or 5 dry very gravelly loam, black (10YR 2/1) moist; weak Chroma: 1 or 2 fine subangular blocky structure parting to Clay content: 15 to 25 percent moderate fine granular structure; slightly hard, Content of rock fragments: 20 to 50 percent—0 to friable, slightly sticky, moderately plastic; many 20 percent cobbles; 20 to 30 percent pebbles very fine and fine and few medium roots; many Reaction: pH 6.6 to 7.8 very fine and fine pores; 5 percent cobbles and Bw horizons 30 percent pebbles; neutral; clear smooth Value: 2 to 5 moist; 4 to 7 dry boundary. Chroma: 2 to 4 Bw1—14 to 28 inches; pale brown (10YR 6/3) very Texture: Loam, sandy loam, or silty clay loam gravelly loam, dark brown (10YR 4/3) moist; Clay content: 15 to 25 percent moderate fine and medium subangular blocky Content of rock fragments: 35 to 60 percent—5 to structure; slightly hard, friable, slightly sticky, 20 percent cobbles; 30 to 40 percent pebbles slightly plastic; common very fine, medium, and Reaction: pH 6.6 to 8.4 coarse and many fine roots; many very fine and fine pores; 5 percent cobbles and 40 percent 2Bk horizon pebbles; slightly alkaline; gradual wavy boundary. Hue: 10YR or 7.5YR Bw2—28 to 37 inches; brown (10YR 5/3) very Value: 3 to 5 moist; 5 to 7 dry gravelly sandy loam, dark brown (10YR 4/3) Chroma: 1 to 4 or 6 moist; few fine distinct reddish yellow (7.5YR 6/6) Texture: Sandy loam, loamy sand, or sand 124 Soil Survey
Clay content: 5 to 10 percent Mean annual precipitation: 10 to 14 inches Content of rock fragments: 40 to 85 percent— Frost-free period: 90 to 105 days 15 to 35 percent cobbles; 25 to 50 percent Composition pebbles Calcium carbonate equivalent: 5 to 15 percent Major Components Reaction: pH 7.4 to 8.4 Kleinschmidt and similar soils: 85 percent Minor Components Poorly drained soils: 0 to 5 percent 547—Kleinschmidt gravelly loam, cool, Soils that have a calcareous surface: 0 to 5 percent 0 to 4 percent slopes Soils that have a saline surface: 0 to 5 percent Major Component Description Setting Surface layer texture: Gravelly loam Landform: Alluvial fans and stream terraces Depth class: Very deep (more than 60 inches) Slope: 0 to 4 percent Drainage class: Somewhat poorly drained Elevation: 3,800 to 5,800 feet Dominant parent material: Alluvium Mean annual precipitation: 15 to 19 inches Native plant cover type: Rangeland Frost-free period: 70 to 90 days Flooding: None Composition Water table: Apparent Available water capacity: Mainly 5.2 inches Major Components Kleinschmidt and similar soils: 85 percent A typical soil description with range in Minor Components characteristics is included, in alphabetical order, in Poorly drained soils: 0 to 5 percent this section. Soils that have a calcareous surface: 0 to 5 percent Management Soils that have a saline surface: 0 to 5 percent For management information about this map unit, Major Component Description see appropriate sections in Part II of this publication. Surface layer texture: Gravelly loam Depth class: Very deep (more than 60 inches) Drainage class: Somewhat poorly drained Lap Series Dominant parent material: Alluvium Depth class: Shallow Native plant cover type: Rangeland Drainage class: Well drained Flooding: None Permeability: Moderate Water table: Apparent Landform: Mountains Available water capacity: Mainly 5.2 inches Parent material: Material derived from limestone Slope range: 15 to 60 percent A typical soil description with range in Elevation range: 4,000 to 5,800 feet characteristics is included, in alphabetical order, in Annual precipitation: 15 to 19 inches this section. Annual air temperature: 39 to 44 degrees F Management Frost-free period: 70 to 90 days For management information about this map unit, Taxonomic Class: Loamy-skeletal, carbonatic, frigid see appropriate sections in Part II of this publication. Lithic Calciustolls
557—Kleinschmidt gravelly loam, Typical Pedon 0 to 4 percent slopes Lap gravelly loam, in an area of Windham-Lap gravelly loams, 15 to 35 percent slopes, in an area of Setting rangeland, 1,700 feet north and 500 feet east of the southwest corner of sec. 12, T. 10 N., R. 7 W. Landform: Alluvial fans and stream terraces Slope: 0 to 4 percent A1—0 to 4 inches; dark grayish brown (10YR 4/2) Elevation: 3,800 to 5,800 feet gravelly loam, very dark grayish brown (10YR Powell County Area, Montana—Part I 125
3/2) moist; weak medium granular structure; soft, Chroma: 2 or 3 very friable, nonsticky, slightly plastic; many very Texture: Loam or clay loam fine, fine, and medium and common coarse roots; Clay content: 20 to 30 percent many very fine interstitial pores; 5 percent stones, Content of rock fragments: 35 to 70 percent—0 to 10 percent cobbles, and 20 percent pebbles; 30 percent stones, flagstones, and cobbles; slightly effervescent; slightly alkaline; clear 30 to 55 percent pebbles or channers smooth boundary. Calcium carbonate equivalent: 30 to 45 percent in A2—4 to 9 inches; dark grayish brown (10YR 4/2) the less than 2 mm particle-size fraction and gravelly loam, very dark grayish brown (10YR more than 40 percent in the less than 20 mm 3/2) moist; moderate medium subangular blocky soil particle-size fraction structure; slightly hard, friable, nonsticky, slightly Reaction: pH 7.9 to 8.4 plastic; many very fine, fine, and medium and Bk2 horizon common coarse roots; many very fine interstitial Hue: 7.5YR, 10YR, or 2.5Y pores; 5 percent stones, 5 percent cobbles, and Value: 6 to 8 dry; 5 or 6 moist 15 percent pebbles; slightly effervescent; slightly Chroma: 2 or 3 alkaline; abrupt smooth boundary. Texture: Loam or clay loam Bk1—9 to 14 inches; brown (10YR 5/3) very gravelly Clay content: 20 to 30 percent loam, brown (10YR 4/3) moist; weak fine Content of rock fragments: 50 to 70 percent— subangular blocky structure; slightly hard, friable, 25 to 35 percent stones, flagstones, and slightly sticky, slightly plastic; common very fine, cobbles; 35 to 60 percent pebbles or channers fine, and medium and few coarse roots; common Calcium carbonate equivalent: 30 to 45 percent in very fine interstitial pores; 5 percent stones, the less than 2 mm particle-size fraction and 15 percent cobbles, and 35 percent pebbles; more than 40 percent in the less than 20 mm disseminated lime; strongly effervescent; soil particle-size fraction moderately alkaline; clear smooth boundary. Reaction: pH 7.9 to 8.4 Bk2—14 to 18 inches; pale brown (10YR 6/3) very cobbly loam, brown (10YR 5/3) moist; moderate fine subangular blocky structure; slightly hard, friable, nonsticky, slightly plastic; few very fine, Libeg Series fine, and medium roots; common very fine Depth class: Very deep interstitial pores; 5 percent stones, 25 percent Drainage class: Well drained cobbles, and 30 percent pebbles; disseminated Permeability: Moderate lime; violently effervescent; moderately alkaline. Landform: Mountains and hills R—18 inches; fractured limestone bedrock. Parent material: Colluvium and material weathered Range in Characteristics from igneous rocks Slope range: 8 to 60 percent Soil temperature: 42 to 47 degrees F Elevation range: 5,700 to 7,500 feet Moisture control section: Between depths of 4 and Annual precipitation: 18 to 22 inches 12 inches Annual air temperature: 34 to 39 degrees F Thickness of the mollic epipedon: 7 to 9 inches Frost-free period: 30 to 70 days Depth to the R horizon: 10 to 20 inches A horizons Taxonomic Class: Loamy-skeletal, mixed, Hue: 10YR or 2.5Y superactive Ustic Argicryolls Value: 4 or 5 dry; 2 or 3 moist Typical Pedon Chroma: 2 or 3 Clay content: 15 to 25 percent Libeg gravelly loam, in an area of Libeg-Monad- Content of rock fragments: 15 to 35 percent—5 to Copenhaver complex, 8 to 15 percent slopes, in an 15 percent stones and cobbles; 10 to 20 area of rangeland, 1,300 feet north and 900 feet west percent pebbles of the southeast corner of sec. 4, T. 8 N., R. 8 W. Calcium carbonate equivalent: 0 to 15 percent A—0 to 10 inches; dark grayish brown (10YR 4/2) Reaction: pH 6.6 to 7.8 gravelly loam, very dark brown (10YR 2/2) moist; Bk1 horizon strong fine granular structure; soft, very friable, Hue: 7.5YR, 10YR, or 2.5Y nonsticky, nonplastic; many very fine and fine Value: 5 to 7 dry; 4 or 5 moist roots; many very fine and fine irregular pores; 126 Soil Survey
5 percent cobbles and 15 percent pebbles; Mean annual precipitation: 18 to 22 inches slightly acid; clear smooth boundary. Frost-free period: 30 to 70 days Bt1—10 to 14 inches; yellowish brown (10YR 5/6) Composition very gravelly loam, dark yellowish brown (10YR 4/6) moist; moderate fine subangular blocky Major Components structure; hard, friable, moderately sticky and Libeg and similar soils: 85 percent moderately plastic; many very fine and fine roots; Minor Components many very fine and fine irregular pores; common Shallow soils that are near rock areas: 0 to 5 percent faint clay films on faces of peds; 15 percent Areas of rock outcrop: 0 to 5 percent cobbles and 45 percent pebbles; slightly acid; Soils that are moderately deep: 0 to 5 percent gradual wavy boundary. Bt2—14 to 60 inches; yellowish brown (10YR 5/6) Major Component Description very gravelly clay loam, dark yellowish brown Surface layer texture: Gravelly loam (10YR 4/6) moist; moderate fine subangular Depth class: Very deep (more than 60 inches) blocky structure; very hard, friable, moderately Drainage class: Well drained sticky and moderately plastic; common very fine Dominant parent material: Igneous colluvium and fine roots; many very fine and fine irregular Native plant cover type: Rangeland pores; common faint clay films on faces of peds; Flooding: None 20 percent cobbles and 40 percent pebbles; Available water capacity: Mainly 5.3 inches slightly acid. Range in Characteristics A typical soil description with range in characteristics is included, in alphabetical order, in Soil temperature: 36 to 44 degrees F this section. Thickness of the mollic epipedon: 8 to 16 inches Management A horizon Hue: 7.5YR or 10YR For management information about this map unit, Value: 3 or 4 dry; 2 or 3 moist see appropriate sections in Part II of this publication. Chroma: 1 or 2 Clay content: 10 to 20 percent Content of rock fragments: 15 to 35 percent—0 to 54E—Libeg gravelly loam, 10 percent stones and cobbles; 15 to 25 15 to 35 percent slopes percent pebbles Reaction: pH 6.1 to 7.3 Setting Bt horizons Landform: Mountains Hue: 5YR, 7.5YR, or 10YR Slope: 15 to 35 percent Value: 4 to 6 dry; 3 to 5 moist Elevation: 5,700 to 7,500 feet Chroma: 2 to 4 or 6 Mean annual precipitation: 18 to 22 inches Texture: Loam, sandy loam, or clay loam Frost-free period: 30 to 70 days Clay content: 15 to 35 percent Composition Content of rock fragments: 35 to 80 percent—5 to 50 percent stones and cobbles; 10 to 45 Major Components percent pebbles Libeg and similar soils: 85 percent Reaction: pH 5.6 to 7.3 Minor Components Shallow soils that are near rock areas: 0 to 5 percent 54D—Libeg gravelly loam, Areas of rock outcrop: 0 to 5 percent 8 to 15 percent slopes Soils that are moderately deep: 0 to 5 percent Major Component Description Setting Surface layer texture: Gravelly loam Landform: Mountains Depth class: Very deep (more than 60 inches) Slope: 8 to 15 percent Drainage class: Well drained Elevation: 5,700 to 7,500 feet Dominant parent material: Igneous colluvium Powell County Area, Montana—Part I 127
Native plant cover type: Rangeland Monad Flooding: None Surface layer texture: Loam Available water capacity: Mainly 5.3 inches Depth class: Very deep (more than 60 inches) Drainage class: Well drained A typical soil description with range in Dominant parent material: Colluvium characteristics is included, in alphabetical order, in Native plant cover type: Rangeland this section. Flooding: None Available water capacity: Mainly 8.1 inches Management For management information about this map unit, Copenhaver see appropriate sections in Part II of this publication. Surface layer texture: Gravelly loam Depth class: Shallow (10 to 20 inches) Drainage class: Well drained 854D—Libeg-Monad-Copenhaver Dominant parent material: Material weathered from complex, 8 to 15 percent slopes igneous rocks Native plant cover type: Rangeland Flooding: None Setting Available water capacity: Mainly 1.4 inches Landform: A typical soil description with range in • Libeg—Hills characteristics is included, in alphabetical order, in • Monad—Hills this section. • Copenhaver—Hills Slope: Management • Libeg—8 to 15 percent • Monad—8 to 15 percent For management information about this map unit, • Copenhaver—8 to 15 percent see appropriate sections in Part II of this publication. Elevation: 5,700 to 7,500 feet Mean annual precipitation: 18 to 22 inches Frost-free period: 30 to 70 days 854E—Libeg-Monad-Copenhaver complex, 15 to 35 percent slopes Composition Setting Major Components Libeg and similar soils: 40 percent Landform: Monad and similar soils: 25 percent • Libeg—Hills Copenhaver and similar soils: 20 percent • Monad—Hills • Copenhaver—Hills Minor Components Slope: Areas of rock outcrop: 0 to 4 percent • Libeg—15 to 35 percent Soils that have a very cobbly surface: 0 to 4 percent • Monad—15 to 35 percent Roy soils: 0 to 4 percent • Copenhaver—15 to 35 percent Soils that have slopes more than 15 percent: 0 to Elevation: 5,700 to 7,500 feet 3 percent Mean annual precipitation: 18 to 22 inches Frost-free period: 30 to 70 days Major Component Description Composition Libeg Major Components Surface layer texture: Gravelly loam Libeg and similar soils: 40 percent Depth class: Very deep (more than 60 inches) Monad and similar soils: 25 percent Drainage class: Well drained Copenhaver and similar soils: 20 percent Dominant parent material: Igneous colluvium Native plant cover type: Rangeland Minor Components Flooding: None Areas of rock outcrop: 0 to 4 percent Available water capacity: Mainly 5.3 inches Libeg very cobbly loam: 0 to 4 percent 128 Soil Survey
Roy soils: 0 to 4 percent Elevation: 5,700 to 7,500 feet Soils that have slopes more than 35 percent: 0 to Mean annual precipitation: 18 to 22 inches 3 percent Frost-free period: 30 to 70 days Major Component Description Composition Libeg Surface layer texture: Gravelly loam Major Components Depth class: Very deep (more than 60 inches) Libeg and similar soils: 40 percent Drainage class: Well drained Monad and similar soils: 25 percent Dominant parent material: Igneous colluvium Copenhaver and similar soils: 20 percent Native plant cover type: Rangeland Minor Components Flooding: None Areas of rock outcrop: 0 to 4 percent Available water capacity: Mainly 5.3 inches Soils that have a very cobbly surface: 0 to 4 percent Roy soils: 0 to 4 percent Monad Soils that have slopes more than 60 percent: 0 to Surface layer texture: Loam 3 percent Depth class: Very deep (more than 60 inches) Drainage class: Well drained Major Component Description Dominant parent material: Colluvium Native plant cover type: Rangeland Libeg Flooding: None Surface layer texture: Gravelly loam Available water capacity: Mainly 8.1 inches Depth class: Very deep (more than 60 inches) Drainage class: Well drained Copenhaver Dominant parent material: Igneous colluvium Surface layer texture: Gravelly loam Native plant cover type: Rangeland Depth class: Shallow (10 to 20 inches) Flooding: None Drainage class: Well drained Available water capacity: Mainly 5.3 inches Dominant parent material: Material weathered from igneous rocks Monad Native plant cover type: Rangeland Surface layer texture: Loam Flooding: None Depth class: Very deep (more than 60 inches) Available water capacity: Mainly 1.4 inches Drainage class: Well drained Dominant parent material: Colluvium A typical soil description with range in Native plant cover type: Rangeland characteristics is included, in alphabetical order, in Flooding: None this section. Available water capacity: Mainly 8.1 inches Management Copenhaver For management information about this map unit, Surface layer texture: Gravelly loam see appropriate sections in Part II of this publication. Depth class: Shallow (10 to 20 inches) Drainage class: Well drained 854F—Libeg-Monad-Copenhaver Dominant parent material: Material weathered from complex, 35 to 60 percent slopes igneous rocks Native plant cover type: Rangeland Flooding: None Setting Available water capacity: Mainly 1.4 inches Landform: • Libeg—Hills A typical soil description with range in • Monad—Hills characteristics is included, in alphabetical order, in • Copenhaver—Hills this section. Slope: Management • Libeg—35 to 60 percent • Monad—35 to 50 percent For management information about this map unit, • Copenhaver—35 to 60 percent see appropriate sections in Part II of this publication. Powell County Area, Montana—Part I 129
Loberg Series hard, firm, moderately sticky and moderately plastic; common very fine, fine, and medium and Depth class: Very deep few coarse roots; common very fine pores; Drainage class: Well drained continuous faint clay films on faces of peds; Permeability: Slow 5 percent cobbles and 40 percent pebbles; Landform: Hills and mountains neutral; clear smooth boundary. Parent material: Colluvium and material weathered Bt3—36 to 47 inches; pale brown (10YR 6/3) very from igneous rocks gravelly clay loam, brown (10YR 5/3) moist; Slope range: 4 to 60 percent strong coarse angular blocky structure; very hard, Elevation range: 4,600 to 7,500 feet very firm, moderately sticky and moderately Annual precipitation: 18 to 30 inches plastic; common very fine and fine and few Annual air temperature: 35 to 38 degrees F medium roots; common very fine pores; Frost-free period: 30 to 70 days continuous faint clay films on faces of peds; 10 percent cobbles and 40 percent pebbles; Taxonomic Class: Clayey-skeletal, mixed, slightly alkaline; clear smooth boundary. superactive Ustic Glossocryalfs BC—47 to 60 inches; pale brown (10YR 6/3) very gravelly clay loam, brown (10YR 5/3) moist; Typical Pedon strong coarse angular blocky structure; very hard, Loberg gravelly loam, 15 to 35 percent slopes, in an very firm, moderately sticky and moderately area of woodland, 1,700 feet south and 1,600 feet plastic; few very fine and fine roots; common very west of the northeast corner of sec. 33, T. 9 N., fine pores; 5 percent cobbles and 40 percent R. 11 W. pebbles; slightly alkaline. Oi—3 inches to 0; partially decomposed forest litter. Range in Characteristics E—0 to 5 inches; light brownish gray (10YR 6/2) gravelly loam, dark grayish brown (10YR 4/2) Soil temperature: 36 to 47 degrees F moist; weak medium subangular blocky structure; Moisture control section: Between depths of 4 and slightly hard, very friable, slightly sticky, slightly 12 inches plastic; many very fine, fine, and medium and few coarse roots; many very fine and fine pores; E horizon 15 percent pebbles; moderately acid; clear wavy Hue: 7.5YR, 10YR, 2.5Y, or 5Y boundary. Value: 5 to 7 dry; 3 to 5 moist E/Bt—5 to 11 inches; 80 percent is light brownish Chroma: 2 or 3 gray (10YR 6/2) very cobbly clay loam, dark Texture: Loam or clay loam grayish brown (10YR 4/2) moist tongues (E part); Clay content: 20 to 35 percent 20 percent is pale brown (10YR 6/3) very cobbly Content of rock fragments: 5 to 35 percent—0 to clay loam, brown (10YR 5/3) moist (B part); weak 10 percent cobbles; 5 to 25 percent pebbles medium subangular blocky structure; slightly Reaction: pH 5.1 to 6.5 hard, very friable, slightly sticky, moderately E/Bt horizon plastic; many very fine, fine, and medium and few Hue: 7.5YR, 10YR, 2.5Y, or 5Y coarse roots; many very fine and fine pores; Value: E part—5 to 7 dry, 3 to 5 moist; B part— 20 percent cobbles and 30 percent pebbles; 4 to 6 dry, 3 to 5 moist slightly acid; clear wavy boundary. Chroma: 2 or 3 Bt1—11 to 19 inches; pale brown (10YR 6/3) very Clay content: 35 to 50 percent gravelly clay loam, brown (10YR 5/3) moist; Content of rock fragments: 20 to 60 percent— moderate medium subangular blocky structure; 15 to 45 percent stones and cobbles; 10 to hard, firm, slightly sticky, moderately plastic; 40 percent pebbles common very fine, fine, and medium and few Reaction: pH 5.1 to 7.8 coarse roots; common very fine pores; continuous faint clay films on faces of peds; Bt horizons 5 percent cobbles and 40 percent pebbles; Hue: 7.5YR, 10YR, 2.5Y, or 5Y neutral; clear wavy boundary. Value: 4 to 6 dry; 3 to 5 moist Bt2—19 to 36 inches; light brownish gray (2.5Y 6/2) Chroma: 2 or 3 very gravelly clay loam, grayish brown (2.5Y 5/2) Texture: Sandy clay, clay, or clay loam moist; strong coarse angular blocky structure; Clay content: 35 to 50 percent 130 Soil Survey
Content of rock fragments: 35 to 60 percent—0 to 85E—Loberg gravelly loam, 45 percent stones and cobbles; 20 to 15 to 35 percent slopes 40 percent pebbles Reaction: pH 5.1 to 7.8 Setting BC horizon Landform: Hills Hue: 7.5YR, 10YR, 2.5Y, or 5Y Slope: 15 to 35 percent Value: 5 or 6 dry; 3 to 5 moist Elevation: 4,600 to 7,500 feet Chroma: 2 or 3 Mean annual precipitation: 18 to 30 inches Texture: Sandy clay, clay, or clay loam Frost-free period: 30 to 70 days Clay content: 35 to 45 percent Content of rock fragments: 35 to 60 percent—5 to Composition 45 percent stones and cobbles; 20 to Major Components 40 percent pebbles Loberg and similar soils: 85 percent Reaction: pH 7.4 to 8.4 Minor Components Danaher soils: 0 to 5 percent 85D—Loberg gravelly loam, Worock soils: 0 to 4 percent 4 to 15 percent slopes Areas of rock outcrop: 0 to 3 percent Poorly drained soils: 0 to 3 percent Setting Major Component Description Landform: Hills Surface layer texture: Gravelly loam Slope: 4 to 15 percent Depth class: Very deep (more than 60 inches) Elevation: 4,600 to 7,500 feet Drainage class: Well drained Mean annual precipitation: 18 to 30 inches Dominant parent material: Material weathered from Frost-free period: 30 to 70 days igneous rocks Native plant cover type: Forestland Composition Flooding: None Major Components Available water capacity: Mainly 4.7 inches Loberg and similar soils: 85 percent A typical soil description with range in Minor Components characteristics is included, in alphabetical order, in Danaher soils: 0 to 6 percent this section. Worock soils: 0 to 6 percent Poorly drained soils: 0 to 3 percent Management Major Component Description For management information about this map unit, see appropriate sections in Part II of this publication. Surface layer texture: Gravelly loam Depth class: Very deep (more than 60 inches) Drainage class: Well drained 385D—Loberg gravelly loam, moist, Dominant parent material: Material weathered from 4 to 15 percent slopes igneous rocks Native plant cover type: Forestland Setting Flooding: None Available water capacity: Mainly 4.7 inches Landform: Hills Slope: 4 to 15 percent A typical soil description with range in Elevation: 4,600 to 7,500 feet characteristics is included, in alphabetical order, in Mean annual precipitation: 18 to 30 inches this section. Frost-free period: 30 to 70 days Management Composition For management information about this map unit, Major Components see appropriate sections in Part II of this publication. Loberg and similar soils: 85 percent Powell County Area, Montana—Part I 131
Minor Components Flooding: None Areas of rock outcrop: 0 to 3 percent Available water capacity: Mainly 4.7 inches Soils that are calcareous at 10 inches: 0 to 3 percent Poorly drained soils: 0 to 3 percent A typical soil description with range in Danaher soils: 0 to 3 percent characteristics is included, in alphabetical order, in Soils that are moderately deep: 0 to 3 percent this section. Major Component Description Management Surface layer texture: Gravelly loam For management information about this map unit, Depth class: Very deep (more than 60 inches) see appropriate sections in Part II of this publication. Drainage class: Well drained Dominant parent material: Material weathered from igneous rocks Marcott Series Native plant cover type: Forestland Depth class: Very deep Flooding: None Drainage class: Somewhat poorly drained Available water capacity: Mainly 4.7 inches Permeability: Slow Landform: Stream terraces A typical soil description with range in Parent material: Clayey alluvium characteristics is included, in alphabetical order, in Slope range: 0 to 4 percent this section. Elevation range: 4,400 to 5,200 feet Management Annual precipitation: 15 to 19 inches Annual air temperature: 39 to 44 degrees F For management information about this map unit, Frost-free period: 70 to 90 days see appropriate sections in Part II of this publication. Taxonomic Class: Fine, smectitic, frigid Vertic 385E—Loberg gravelly loam, moist, Haplustolls 15 to 35 percent slopes Typical Pedon Marcott silty clay loam, 0 to 4 percent slopes, in an Setting area of hayland, 100 feet south and 900 feet east of Landform: Hills the northwest corner of sec. 29, T. 12 N., R. 9 W. Slope: 15 to 35 percent Oi—1 inch to 0; slightly decomposed grass litter. Elevation: 4,600 to 7,500 feet Az—0 to 10 inches; dark gray (10YR 4/1) silty clay Mean annual precipitation: 18 to 30 inches loam, very dark gray (10YR 3/1) moist; strong Frost-free period: 30 to 70 days medium and coarse angular blocky structure; Composition hard, firm, moderately sticky and moderately plastic; many fine and medium roots; common Major Components very fine tubular pores; few medium seams of Loberg and similar soils: 85 percent salt; moderately alkaline; clear wavy boundary. Minor Components Bz—10 to 15 inches; grayish brown (10YR 5/2) silty Areas of rock outcrop: 0 to 4 percent clay loam, very dark gray (10YR 3/1) moist; weak Soils that are moderately deep: 0 to 4 percent coarse prismatic structure parting to strong fine Soils that have slopes more than 35 percent: 0 to and medium angular blocky; hard, firm, very 4 percent sticky and very plastic; common fine and medium Poorly drained soils: 0 to 3 percent roots; common very fine tubular pores; many medium seams of salt; moderately alkaline; clear Major Component Description wavy boundary. Surface layer texture: Gravelly loam Bkz1—15 to 20 inches; light brownish gray (10YR Depth class: Very deep (more than 60 inches) 6/2) clay loam, dark grayish brown (10YR 4/2) Drainage class: Well drained moist; moderate medium subangular blocky Dominant parent material: Material weathered from structure; hard, firm, moderately sticky and igneous rocks moderately plastic; few very fine roots; many Native plant cover type: Forestland medium seams and masses of salt and lime; 132 Soil Survey
slightly effervescent; moderately alkaline; clear Bz horizon wavy boundary. Hue: 10YR, 2.5Y, or 5Y Bkz2—20 to 24 inches; light gray (10YR 7/2) clay Value: 4 to 7 dry; 3 to 5 moist loam, grayish brown (10YR 5/2) moist; common Chroma: 1 to 3 fine and medium prominent brownish yellow Texture: Clay loam, silty clay loam, silty clay, or (10YR 6/6) redox concentrations; weak fine clay subangular blocky structure; hard, firm, very Clay content: 35 to 50 percent sticky and moderately plastic; 10 percent Content of rock fragments: 0 to 5 percent pebbles pebbles; many masses of salt and lime; strongly Electrical conductivity: 2 to 8 mmhos/cm effervescent; moderately alkaline; clear wavy Sodium adsorption ratio: 0 to 25 boundary. Calcium carbonate equivalent: 3 to 12 percent Bkzg1—24 to 37 inches; light gray (2.5Y 7/2) silty Reaction: pH 7.4 to 8.4 clay, dark grayish brown (2.5Y 4/2) moist; Bkz and Akzb horizons common fine and medium prominent brownish Hue: 10YR, 2.5Y, or 5Y yellow (10YR 6/6) redox concentrations; weak Value: 4 to 7 dry; 3 to 6 moist fine subangular blocky structure; hard, firm, Chroma: 1 to 3 moderately sticky and moderately plastic; many Texture: Clay loam, silty clay loam, silty clay, or medium seams of salt and lime; strongly clay effervescent; very strongly alkaline; gradual Clay content: 35 to 50 percent smooth boundary. Content of rock fragments: 0 to 15 percent—0 to Bkzg2—37 to 50 inches; gray (N 6/) silty clay, dark 5 percent cobbles; 0 to 10 percent pebbles grayish brown (10YR 4/2) moist; weak fine Electrical conductivity: 4 to 8 mmhos/cm subangular blocky structure; very hard, very firm, Sodium adsorption ratio: 0 to 30 very sticky and very plastic; common large seams Calcium carbonate equivalent: 5 to 15 percent and masses of salt and lime; slightly effervescent; Reaction: pH 7.4 to 9.0 very strongly alkaline; clear smooth boundary. Akzb—50 to 60 inches; dark gray (10YR 4/1) silty clay loam, very dark gray (10YR 3/1) moist; weak 549—Marcott silty clay loam, fine subangular blocky structure; hard, firm, 0 to 4 percent slopes moderately sticky and very plastic; common large seams of salt and lime; slightly effervescent; very Setting strongly alkaline. Landform: Stream terraces Range in Characteristics Slope: 0 to 4 percent Soil temperature: 41 to 47 degrees F Elevation: 4,400 to 5,200 feet Moisture control section: Between depths of 4 and Mean annual precipitation: 15 to 19 inches 12 inches Frost-free period: 70 to 90 days Thickness of the mollic epipedon: 7 to 15 inches Composition Depth to the Bkz horizon: 12 to 24 inches Depth to the seasonal water table: 24 to 42 inches Major Components Other features: Some pedons do not have a Akzb Marcott and similar soils: 85 percent horizon. Some pedons have a 2C horizon at Minor Components depths greater than 36 inches. Gregson soils: 0 to 5 percent Az horizon Poorly drained soils: 0 to 5 percent Hue: 10YR, 2.5Y, or 5Y Carten soils: 0 to 5 percent Value: 3 to 5 dry; 2 or 3 moist Major Component Description Chroma: 1 or 2 Clay content: 30 to 40 percent Surface layer texture: Silty clay loam Content of rock fragments: 0 to 5 percent pebbles Depth class: Very deep (more than 60 inches) Electrical conductivity: 4 to 8 mmhos/cm Drainage class: Somewhat poorly drained Sodium adsorption ratio: 0 to 20 Dominant parent material: Alluvium Reaction: pH 6.6 to 8.4 Native plant cover type: Rangeland Powell County Area, Montana—Part I 133
Flooding: None sticky, slightly plastic; common very fine and fine Water table: Apparent roots; common fine and medium tubular pores; Salt affected: Saline within 30 inches 5 percent pebbles; common fine and medium Sodium affected: Sodic within 30 inches masses of lime; strongly effervescent; slightly Available water capacity: Mainly 8.8 inches alkaline; gradual wavy boundary. Bk2—18 to 33 inches; white (10YR 8/2) loam, very A typical soil description with range in pale brown (10YR 7/3) moist; weak medium characteristics is included, in alphabetical order, in subangular blocky structure; slightly hard, very this section. friable, slightly sticky, slightly plastic; few very fine and fine roots; common very fine and fine tubular Management pores; 5 percent pebbles; common fine and For management information about this map unit, medium masses of lime; violently effervescent; see appropriate sections in Part II of this publication. moderately alkaline; gradual wavy boundary. Bk3—33 to 60 inches; white (10YR 8/2) loam, pale brown (10YR 6/3) moist; weak medium Martinsdale Series subangular blocky structure; slightly hard, very friable, nonsticky, nonplastic; few very fine roots; Depth class: Very deep common fine irregular pores; 10 percent pebbles; Drainage class: Well drained disseminated lime; violently effervescent; Permeability: Moderately slow moderately alkaline. Landform: Alluvial fans and stream terraces Parent material: Alluvium Range in Characteristics Slope range: 0 to 35 percent Elevation range: 3,800 to 5,800 feet Soil temperature: 41 to 47 degrees F Annual precipitation: 15 to 19 inches Moisture control section: Between depths of 4 and Annual air temperature: 39 to 44 degrees F 12 inches; moist in all or some parts from April Frost-free period: 70 to 90 days through mid July and September through mid November Taxonomic Class: Fine-loamy, mixed, superactive, Thickness of the mollic epipedon: 7 to 16 inches and frigid Typic Argiustolls includes all or part of the Bt horizon Depth to the Bk horizon: 11 to 30 inches Typical Pedon Soil phases: Gravelly Martinsdale loam, 0 to 4 percent slopes, in an area of A horizon rangeland, 1,450 feet north and 2,350 feet east of the Hue: 7.5YR or 10YR southwest corner of sec. 22, T. 8 N., R. 10 W. Value: 4 or 5 dry; 2 or 3 moist A—0 to 5 inches; dark grayish brown (10YR 4/2) Chroma: 2 or 3 loam, very dark grayish brown (10YR 3/2) moist; Clay content: 18 to 27 percent moderate medium granular structure; slightly Content of rock fragments: 0 to 25 percent—0 to hard, very friable, slightly sticky, slightly plastic; 10 percent cobbles; 0 to 15 percent pebbles many very fine and fine and common medium Reaction: pH 6.6 to 7.8 roots; many fine irregular pores; neutral; clear Bt horizon smooth boundary. Hue: 7.5YR or 10YR Bt—5 to 13 inches; brown (10YR 5/3) clay loam, very Value: 4 or 5 dry; 2 or 3 moist dark grayish brown (10YR 3/2) moist; moderate Chroma: 2 to 4 medium prismatic structure parting to weak fine Texture: Sandy clay loam, loam, or clay loam and medium subangular blocky; hard, friable, Clay content: 25 to 35 percent slightly sticky, moderately plastic; many very fine Content of rock fragments: 0 to 15 percent—0 to and fine and few coarse roots; many very fine 5 percent cobbles; 0 to 15 percent pebbles and fine tubular pores; common faint dark grayish Reaction: pH 6.6 to 8.4 brown (10YR 4/2) clay films on faces of peds; neutral; clear wavy boundary. Bk horizons Bk1—13 to 18 inches; light gray (10YR 7/2) loam, Hue: 10YR or 2.5Y brown (10YR 5/3) moist; moderate medium Value: 6 to 8 dry; 4 to 7 moist subangular blocky structure; hard, friable, slightly Chroma: 2 to 4 134 Soil Survey
Texture: Loam, clay loam, sandy clay loam, or Elevation: 4,400 to 5,800 feet sandy loam Mean annual precipitation: 15 to 19 inches Clay content: 20 to 35 percent Frost-free period: 70 to 90 days Calcium carbonate equivalent: 15 to 35 percent Content of rock fragments: 0 to 25 percent—0 to Composition 5 percent cobbles; 0 to 20 percent pebbles Reaction: pH 7.4 to 8.4 Major Components Martinsdale and similar soils: 85 percent 52B—Martinsdale loam, Minor Components 0 to 4 percent slopes Soils that have slopes more than 8 percent: 0 to 5 percent Martinsdale cobbly loam: 0 to 5 percent Setting Soils that are very gravelly below 10 inches: 0 to Landform: Stream terraces 5 percent Slope: 0 to 4 percent Elevation: 4,400 to 5,800 feet Major Component Description Mean annual precipitation: 15 to 19 inches Frost-free period: 70 to 90 days Surface layer texture: Loam Depth class: Very deep (more than 60 inches) Composition Drainage class: Well drained Major Components Dominant parent material: Alluvium Martinsdale and similar soils: 85 percent Native plant cover type: Rangeland Flooding: None Minor Components Available water capacity: Mainly 9.1 inches Martinsdale gravely loam soils: 0 to 5 percent Soils that have slopes more than 4 percent: 0 to A typical soil description with range in 5 percent characteristics is included, in alphabetical order, in Soils that are very gravelly below 10 inches: 0 to this section. 5 percent Management Major Component Description For management information about this map unit, Surface layer texture: Loam see appropriate sections in Part II of this publication. Depth class: Very deep (more than 60 inches) Drainage class: Well drained Dominant parent material: Alluvium Native plant cover type: Rangeland 52D—Martinsdale loam, Flooding: None 8 to 15 percent slopes Available water capacity: Mainly 9.1 inches Setting A typical soil description with range in characteristics is included, in alphabetical order, in Landform: Alluvial fans this section. Slope: 8 to 15 percent Elevation: 4,400 to 5,800 feet Management Mean annual precipitation: 15 to 19 inches For management information about this map unit, Frost-free period: 70 to 90 days see appropriate sections in Part II of this publication. Composition Major Components 52C—Martinsdale loam, Martinsdale and similar soils: 85 percent 4 to 8 percent slopes Minor Components Soils that have slopes more than 15 percent: 0 to Setting 5 percent Landform: Alluvial fans Martinsdale cobbly loam: 0 to 5 percent Slope: 4 to 8 percent Soils that are very gravelly throughout: 0 to 5 percent Powell County Area, Montana—Part I 135
Major Component Description 352E—Martinsdale cobbly loam, Surface layer texture: Loam 15 to 35 percent slopes Depth class: Very deep (more than 60 inches) Drainage class: Well drained Setting Dominant parent material: Alluvium Landform: Alluvial fans Native plant cover type: Rangeland Slope: 15 to 35 percent Flooding: None Elevation: 4,400 to 5,800 feet Available water capacity: Mainly 9.1 inches Mean annual precipitation: 15 to 19 inches Frost-free period: 70 to 90 days A typical soil description with range in characteristics is included, in alphabetical order, in Composition this section. Major Components Management Martinsdale and similar soils: 85 percent For management information about this map unit, Minor Components see appropriate sections in Part II of this publication. Soils that slopes more than 35 percent: 0 to 5 percent Soils that are calcareous throughout: 0 to 5 percent Martinsdale very gravelly loam: 0 to 5 percent 352B—Martinsdale cobbly loam, 0 to 4 percent slopes Major Component Description
Setting Surface layer texture: Cobbly loam Depth class: Very deep (more than 60 inches) Landform: Stream terraces Drainage class: Well drained Slope: 0 to 4 percent Dominant parent material: Alluvium Elevation: 4,400 to 5,800 feet Native plant cover type: Rangeland Mean annual precipitation: 15 to 19 inches Flooding: None Frost-free period: 70 to 90 days Available water capacity: Mainly 8.8 inches Composition A typical soil description with range in Major Components characteristics is included, in alphabetical order, in Martinsdale and similar soils: 85 percent this section. Minor Components Management Soils that have slopes more than 4 percent: 0 to 5 percent For management information about this map unit, Martinsdale very gravelly loam: 0 to 5 percent see appropriate sections in Part II of this publication. Danvers soils: 0 to 5 percent Major Component Description Mccabe Series Surface layer texture: Cobbly loam Depth class: Very deep (more than 60 inches) Depth class: Very deep Drainage class: Well drained Drainage class: Poorly drained Dominant parent material: Alluvium Permeability: Moderately rapid Native plant cover type: Rangeland Landform: Flood plains Flooding: None Parent material: Alluvium Available water capacity: Mainly 8.8 inches Slope range: 0 to 2 percent Elevation range: 4,000 to 4,100 feet A typical soil description with range in Annual precipitation: 10 to 14 inches characteristics is included, in alphabetical order, in Annual air temperature: 39 to 44 degrees F this section. Frost-free period: 90 to 105 days Management Taxonomic Class: Coarse-loamy over sandy or For management information about this map unit, sandy-skeletal, mixed, superactive, nonacid, see appropriate sections in Part II of this publication. frigid Aeric Fluvaquents 136 Soil Survey
Typical Pedon Depth to the seasonal high water table: 12 to 24 inches Mccabe loam, in an area of Mccabe-Canarway complex, 0 to 2 percent slopes, occasionally flooded, A horizon in an area of pasture, 2,350 feet south and 100 feet Value: 3 to 5 moist; 5 or 6 dry east of the northwest corner of sec. 22, T. 11 N., Chroma: 1 or 2 R. 15 W. Clay content: 5 to 15 percent Calcium carbonate equivalent: 0 to 5 percent A—0 to 2 inches; very dark grayish brown (10YR 3/2) Reaction: pH 6.6 to 7.8 loam, grayish brown (10YR 5/2) dry; moderate medium granular structure; soft, friable, slightly C1 and C2 horizons sticky, slightly plastic; many very fine and fine Value: 3 to 6 moist; 5 to 7 dry roots; common fine tubular pores; neutral; clear Chroma: 1 or 2 smooth boundary. Texture: Loam, sandy loam, or fine sandy loam C1—2 to 4 inches; very dark grayish brown (10YR Clay content: 10 to 18 percent, with less than 3/2) fine sandy loam, light brownish gray (10YR 50 percent fine sand and coarser 6/2) dry; weak fine granular structure; soft, very Calcium carbonate equivalent: 0 to 10 percent friable, slightly sticky, slightly plastic; many very Reaction: pH 6.6 to 8.4 fine and fine roots; common very fine interstitial C3 and C4 horizons pores; slightly alkaline; clear smooth boundary. Value: 3 or 4 moist; 5 or 6 dry C2—4 to 9 inches; dark grayish brown (10YR 4/2) Chroma: 1 to 3 sandy loam, grayish brown (10YR 5/2) dry; Redox concentrations: Hue—10YR or 2.5YR; moderate medium granular structure; soft, friable, Value—4 or 5 moist; 5 or 6 dry; Chroma—4, 5, slightly sticky, slightly plastic; many very fine and 6, or 8 fine roots; common very fine tubular pores; Texture: Loam, very fine sandy loam, fine sandy slightly alkaline; gradual wavy boundary. loam, or sandy loam C3—9 to 16 inches; dark grayish brown (10YR 4/2) Clay content: 5 to 18 percent, with less than sandy loam consisting of strata of loam, fine 50 percent fine sand and coarser sandy loam and sandy loam, grayish brown Calcium carbonate equivalent: 0 to 15 percent (10YR 5/2) dry; many medium distinct yellowish Reaction: pH 6.6 to 8.4 brown (10YR 5/8), brownish yellow (10YR 6/8) dry redox concentrations; weak fine subangular 2C5 horizon blocky structure; soft, very friable, nonsticky, Value: 3 or 4 moist; 5 or 6 dry slightly plastic; common very fine and fine roots; Chroma: 1 or 2 few fine tubular pores; slightly alkaline; clear wavy Texture: Loamy sand or sand boundary. Clay content: 0 to 10 percent C4—16 to 36 inches; dark grayish brown (10YR 4/2) Content of rock fragments: 40 to 60 percent— fine sandy loam consisting of strata of loam and 15 to 25 percent cobbles; 25 to 35 percent fine sandy loam, grayish brown (10YR 5/2) dry; pebbles many medium distinct yellowish brown (10YR Calcium carbonate equivalent: 0 to 15 percent 5/8), brownish yellow (10YR 6/8) dry redox Reaction: pH 6.6 to 7.8 concentrations; weak fine granular structure; soft, very friable, nonsticky, nonplastic; common very fine and fine roots; few fine tubular pores; slightly 10A—Mccabe-Canarway complex, alkaline; clear wavy boundary. impacted, 0 to 2 percent slopes, 2C5—36 to 60 inches; very dark grayish brown occasionally flooded (10YR 3/2) very gravelly loamy sand, grayish brown (10YR 5/2) dry; single grain; loose, Setting nonsticky, nonplastic; common very fine and fine roots; few fine tubular pores; 20 percent cobbles Landform: and 35 percent pebbles; slightly alkaline. • Mccabe—Flood plains • Canarway—Flood plains Range in Characteristics Slope: Soil temperature: 41 to 46 degrees F • Mccabe—0 to 2 percent Moisture control section: Between depths of 8 and • Canarway—0 to 2 percent 24 inches Elevation: 4,000 to 4,100 feet Powell County Area, Montana—Part I 137
Mean annual precipitation: 10 to 14 inches Composition Frost-free period: 90 to 105 days Major Components Composition Mccabe and similar soils: 45 percent Canarway and similar soils: 40 percent Major Components Mccabe and similar soils: 45 percent Minor Components Canarway and similar soils: 40 percent Very poorly drained soils: 0 to 5 percent Areas of open water: 0 to 5 percent Minor Components Areas of riverwash: 0 to 5 percent Very poorly drained soils: 0 to 5 percent Areas of open water: 0 to 5 percent Major Component Description Areas of riverwash: 0 to 5 percent Mccabe Major Component Description Surface layer texture: Sandy loam Depth class: Very deep (more than 60 inches) Mccabe Drainage class: Poorly drained Surface layer texture: Sandy loam Dominant parent material: Alluvium Depth class: Very deep (more than 60 inches) Native plant cover type: Rangeland Drainage class: Poorly drained Flooding: Occasional Dominant parent material: Alluvium Water table: Apparent Flooding: Occasional Available water capacity: Mainly 6.1 inches Water table: Apparent Available water capacity: Mainly 6.1 inches Canarway Surface layer texture: Gravelly sandy loam Canarway Depth class: Very deep (more than 60 inches) Surface layer texture: Gravelly sandy loam Drainage class: Poorly drained Depth class: Very deep (more than 60 inches) Dominant parent material: Alluvium Drainage class: Poorly drained Native plant cover type: Rangeland Dominant parent material: Alluvium Flooding: Occasional Flooding: Occasional Water table: Apparent Water table: Apparent Available water capacity: Mainly 2.8 inches Available water capacity: Mainly 2.8 inches A typical soil description with range in A typical soil description with range in characteristics is included, in alphabetical order, in characteristics is included, in alphabetical order, in this section. this section. Management Management For management information about this map unit, For management information about this map unit, see appropriate sections in Part II of this publication. see appropriate sections in Part II of this publication.
M-W—Miscellaneous Water 11A—Mccabe-Canarway complex, 0 to 2 percent slopes, occasionally flooded Composition Major Components Setting Miscellaneous water: 100 percent Landform: Major Component Description • Mccabe—Flood plains Definition: Areas of open water in sewage lagoons, • Canarway—Flood plains industrial waste pits, fish hatcheries, etc. Slope: • Mccabe—0 to 2 percent • Canarway—0 to 2 percent Mocmont Series Elevation: 4,000 to 4,100 feet Mean annual precipitation: 10 to 14 inches Depth class: Very deep Frost-free period: 90 to 105 days Drainage class: Well drained 138 Soil Survey
Permeability: Moderately rapid common distinct clay films on faces of peds and Landform: Mountains on pebbles; 20 percent cobbles and 45 percent Parent material: Colluvium derived from quartzite and pebbles; moderately acid; gradual wavy argillite boundary. Slope range: 15 to 60 percent BC—26 to 60 inches; pale brown (10YR 6/3) Elevation range: 3,800 to 6,500 feet extremely gravelly loam, brown (10YR 5/3) moist; Annual precipitation: 18 to 26 inches moderate fine subangular blocky structure; Annual air temperature: 38 to 42 degrees F slightly hard, friable, slightly sticky, slightly plastic; Frost-free period: 70 to 90 days common very fine and few fine roots; common very fine and fine discontinuous irregular pores; Taxonomic Class: Loamy-skeletal, mixed, 25 percent cobbles and 50 percent pebbles; superactive, frigid Typic Haplustalfs moderately acid. Range in Characteristics Typical Pedon Soil temperature: 42 to 45 degrees F Mocmont very gravelly loam, 15 to 35 percent slopes, Moisture control section: Between depths of 4 and in an area of woodland, 2,700 feet north and 200 feet 12 inches west of the southeast corner of sec. 36, T. 14 N., Depth to the argillic horizon: 10 to 24 inches R. 10 W. E horizons Oe—2 inches to 0; partially decomposed organic Hue: 7.5YR or 10YR matter. Value: 5 to 8 dry; 4 to 6 moist E1—0 to 5 inches; grayish brown (10YR 5/2) very Chroma: 2 or 3 gravelly loam, dark grayish brown (10YR 4/2) Clay content: 15 to 20 percent moist; weak fine subangular blocky structure; soft, Content of rock fragments: 35 to 60 percent—0 to very friable, slightly sticky, slightly plastic; many 10 percent angular cobbles; 35 to 50 percent very fine and fine and common medium and angular pebbles or channers coarse roots; many very fine and fine Reaction: pH 5.6 to 7.3 discontinuous irregular pores; 40 percent pebbles; neutral; clear smooth boundary. E/Bt horizon E2—5 to 9 inches; grayish brown (10YR 5/2) very Hue: 7.5YR or 10YR gravelly loam, very dark grayish brown (10YR Value: E part—6 or 7 dry, 4 or 5 moist; B part— 4/2) moist; moderate fine subangular blocky 5 to 7 dry, 4 or 5 moist structure; slightly hard, friable, slightly sticky, Chroma: 2 to 4 slightly plastic; many very fine and fine and Texture: E part—sandy loam or loam; B part— common medium and coarse roots; many very loam or clay loam fine and fine discontinuous irregular pores; Clay content: E part—10 to 20 percent; B part— 5 percent cobbles and 40 percent pebbles; 25 to 35 percent slightly acid; gradual wavy boundary. Content of rock fragments: 35 to 60 percent— E/Bt—9 to 18 inches; 75 percent is light brownish 10 to 30 percent angular cobbles; 25 to 55 gray (10YR 6/2) very gravelly loam, dark grayish percent angular pebbles or channers brown (10YR 4/2) moist (E part); 25 percent is Reaction: pH 5.6 to 7.3 pale brown (10YR 6/3) very gravelly loam, dark Bt horizon brown (10YR 4/3) moist (B part); moderate Hue: 5YR, 7.5YR, or 10YR medium subangular blocky structure; slightly Value: 5 to 7 dry; 4 or 5 moist hard, friable, slightly sticky, slightly plastic; Chroma: 3, 4, or 6 common very fine and few fine roots; common Texture: Loam, clay loam, or sandy clay loam very fine and fine discontinuous irregular pores; Clay content: 15 to 30 percent 10 percent cobbles and 35 percent pebbles; Content of rock fragments: 35 to 85 percent— slightly acid; gradual wavy boundary. 10 to 30 percent angular cobbles; 25 to 55 Bt—18 to 26 inches; pale brown (10YR 6/3) percent angular pebbles or channers extremely gravelly loam, dark brown (10YR 4/3) Reaction: pH 5.6 to 7.3 moist; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic; BC horizon common very fine and few fine roots; common Hue: 5YR, 7.5YR, or 10YR very fine and fine discontinuous irregular pores; Value: 5 or 6 dry; 4 or 5 moist Powell County Area, Montana—Part I 139
Chroma: 3, 4, or 6 Composition Texture: Loam or sandy loam Major Components Clay content: 10 to 25 percent Mocmont and similar soils: 85 percent Content of rock fragments: 60 to 90 percent— 25 to 40 percent stones and cobbles; 35 to Minor Components 50 percent angular pebbles or channers Soils that have slopes more than 35 percent: 0 to Reaction: pH 5.6 to 7.3 5 percent Soils that have a calcareous subsoil: 0 to 5 percent Rumblecreek soils: 0 to 5 percent 90F—Mocmont very gravelly loam, moist, Major Component Description 35 to 60 percent slopes Surface layer texture: Very gravelly loam Depth class: Very deep (more than 60 inches) Setting Drainage class: Well drained Landform: Mountains Dominant parent material: Colluvium Slope: 35 to 60 percent Native plant cover type: Forestland Elevation: 3,800 to 6,500 feet Flooding: None Mean annual precipitation: 18 to 26 inches Available water capacity: Mainly 2.8 inches Frost-free period: 70 to 90 days A typical soil description with range in Composition characteristics is included, in alphabetical order, in Major Components this section. Mocmont and similar soils: 85 percent Management Minor Components For management information about this map unit, Yreka soils: 0 to 15 percent see appropriate sections in Part II of this publication. Major Component Description Surface layer texture: Very gravelly loam 190F—Mocmont very gravelly loam, Depth class: Very deep (more than 60 inches) 35 to 60 percent slopes Drainage class: Well drained Dominant parent material: Colluvium Setting Native plant cover type: Forestland Flooding: None Landform: Mountains Available water capacity: Mainly 2.8 inches Slope: 35 to 60 percent Elevation: 3,800 to 6,500 feet A typical soil description with range in Mean annual precipitation: 18 to 26 inches characteristics is included, in alphabetical order, in Frost-free period: 70 to 90 days this section. Composition Management Major Components For management information about this map unit, Mocmont and similar soils: 85 percent see appropriate sections in Part II of this publication. Minor Components Areas of rock outcrop: 0 to 4 percent 190E—Mocmont very gravelly loam, Soils that have a calcareous subsoil: 0 to 4 percent 15 to 35 percent slopes Rumblecreek soils: 0 to 4 percent Soils that are moderately deep: 0 to 3 percent Setting Major Component Description Landform: Mountains Surface layer texture: Very gravelly loam Slope: 15 to 35 percent Depth class: Very deep (more than 60 inches) Elevation: 3,800 to 6,500 feet Drainage class: Well drained Mean annual precipitation: 18 to 26 inches Dominant parent material: Colluvium Frost-free period: 70 to 90 days Native plant cover type: Forestland 140 Soil Survey
Flooding: None faces of peds; 10 percent pebbles; moderately Available water capacity: Mainly 2.8 inches acid; abrupt smooth boundary. Bt2—16 to 29 inches; light yellowish brown (10YR A typical soil description with range in 6/4) clay loam, dark yellowish brown (10YR 4/4) characteristics is included, in alphabetical order, in moist; moderate medium subangular blocky this section. structure; hard, friable, slightly sticky, moderately plastic; common very fine and few fine and Management medium roots; common very fine and few fine For management information about this map unit, and medium irregular pores; common distinct see appropriate sections in Part II of this publication. clay films on faces of peds; 5 percent cobbles and 10 percent pebbles; moderately acid; abrupt wavy boundary. Mollet Series Bt3—29 to 60 inches; light yellowish brown (10YR 6/4) gravelly clay loam, dark yellowish brown Depth class: Very deep (10YR 4/4) moist; strong medium subangular Drainage class: Well drained blocky structure; very hard, friable, moderately Permeability: Slow sticky and moderately plastic; few very fine and Landform: Mountains, alluvial fans, and stream fine roots; common very fine and few fine and terraces medium tubular pores; few faint clay films on Parent material: Alluvium and colluvium from fine- faces of peds; 5 percent cobbles and 10 percent grained extrusive igneous rocks pebbles; moderately acid. Slope range: 4 to 35 percent Elevation range: 5,400 to 7,000 feet Range in Characteristics Annual precipitation: 15 to 22 inches Soil temperature: 36 to 41 degrees F Annual air temperature: 34 to 39 degrees F Moisture control section: Between depths of 4 and Frost-free period: 30 to 70 days 12 inches Thickness of the mollic epipedon: 10 to 16 inches Taxonomic Class: Fine, mixed, superactive Ustic Argicryolls A horizons Value: 3 to 5 dry; 2 or 3 moist Typical Pedon Chroma: 1 or 2 Mollet loam, 4 to 15 percent slopes, in an area of Clay content: 20 to 27 percent rangeland, 1,100 feet south and 800 feet east of the Content of rock fragments: 0 to 35 percent—0 to northwest corner of sec. 11, T. 10 N., R. 6 W. 15 percent cobbles; 0 to 20 percent pebbles Reaction: pH 5.6 to 6.5 A1—0 to 7 inches; dark grayish brown (10YR 4/2) loam, very dark brown (10YR 2/2) moist; weak Bt1 horizon fine granular structure; slightly hard, very friable, Value: 4 to 6 dry; 3 or 4 moist nonsticky, nonplastic; many very fine, common Chroma: 2 or 3 fine, and few medium roots; many very fine and Texture: Clay loam, silty clay loam, or clay fine irregular pores; 5 percent pebbles; Clay content: 35 to 50 percent moderately acid; clear wavy boundary. Content of rock fragments: 0 to 15 percent—0 to A2—7 to 12 inches; grayish brown (10YR 5/2) loam, 5 percent cobbles; 0 to 10 percent pebbles very dark brown (10YR 2/2) moist; weak very fine Reaction: pH 5.6 to 6.5 subangular blocky structure; hard, friable, Bt2 horizon nonsticky, nonplastic; many very fine, common Texture: Clay loam, clay, or silty clay loam fine, and few medium roots; few very fine and fine Clay content: 35 to 45 percent tubular pores; 10 percent pebbles; moderately Content of rock fragments: 5 to 15 percent—0 to acid; abrupt wavy boundary. 5 percent cobbles; 5 to 10 percent pebbles Bt1—12 to 16 inches; pale brown (10YR 6/3) clay Reaction: pH 5.6 to 6.5 loam, brown (10YR 4/3) moist; weak medium subangular blocky structure; hard, friable, slightly Bt3 horizon sticky, slightly plastic; common very fine and few Texture: Clay loam or clay fine and medium roots; common very fine and Chroma: 4 or 6 fine tubular pores; common distinct clay films on Clay content: 35 to 45 percent Powell County Area, Montana—Part I 141
Content of rock fragments: 15 to 35 percent—5 to Minor Components 10 percent cobbles; 10 to 25 percent pebbles Soils that are very gravelly throughout: 0 to Reaction: pH 5.6 to 7.3 10 percent Soils that have slopes more than 35 percent: 0 to 5 percent 48D—Mollet loam, 4 to 15 percent slopes Major Component Description Setting Surface layer texture: Loam Depth class: Very deep (more than 60 inches) Landform: Alluvial fans Drainage class: Well drained Slope: 4 to 15 percent Dominant parent material: Alluvium or colluvium Elevation: 5,400 to 7,000 feet Native plant cover type: Rangeland Mean annual precipitation: 15 to 22 inches Flooding: None Frost-free period: 30 to 70 days Available water capacity: Mainly 8.9 inches Composition A typical soil description with range in Major Components characteristics is included, in alphabetical order, in Mollet and similar soils: 85 percent this section. Minor Components Management Soils that are very gravelly throughout: 0 to 10 percent For management information about this map unit, Soils that have slopes more than 15 percent: 0 to see appropriate sections in Part II of this publication. 5 percent Major Component Description Monad Series Surface layer texture: Loam Depth class: Very deep (more than 60 inches) Depth class: Very deep Drainage class: Well drained Drainage class: Well drained Dominant parent material: Alluvium or colluvium Permeability: Moderately slow Native plant cover type: Rangeland Landform: Hills Flooding: None Parent material: Material derived from fine-grained Available water capacity: Mainly 8.9 inches extrusive igneous rocks and colluvium Slope range: 2 to 50 percent A typical soil description with range in Elevation range: 5,400 to 7,500 feet characteristics is included, in alphabetical order, in Annual precipitation: 18 to 22 inches this section. Annual air temperature: 34 to 39 degrees F Frost-free period: 30 to 70 days Management For management information about this map unit, Taxonomic Class: Fine-loamy, mixed, superactive see appropriate sections in Part II of this publication. Alfic Argicryolls Typical Pedon 48E—Mollet loam, 15 to 35 percent slopes Monad loam, 2 to 8 percent slopes, in an area of rangeland, 1,800 feet south and 2,500 feet west of Setting the northeast corner of sec. 15, T. 8 N., R. 8 W. Landform: Alluvial fans A—0 to 11 inches; very dark grayish brown (10YR Slope: 15 to 35 percent 3/2) loam, black (10YR 2/1) moist; moderate Elevation: 5,400 to 7,000 feet medium granular structure; soft, very friable, Mean annual precipitation: 15 to 22 inches nonsticky, nonplastic; many very fine roots; many Frost-free period: 30 to 70 days very fine and fine pores; slightly acid; clear smooth boundary. Composition Bt1—11 to 25 inches; yellowish brown (10YR 5/4) Major Components clay loam, brown (10YR 4/3) moist; weak fine Mollet and similar soils: 85 percent subangular blocky structure; very hard, firm, 142 Soil Survey
slightly sticky, slightly plastic; many very fine and Minor Components fine roots; many very fine and fine pores; few faint Soils that are very gravelly throughout: 0 to 8 percent clay films on faces of peds; 15 percent pebbles; Soils that have a clayey subsoil: 0 to 7 percent slightly acid; gradual wavy boundary. Major Component Description Bt2—25 to 60 inches; yellowish brown (10YR 5/4) gravelly clay loam, brown (10YR 4/3) moist; weak Surface layer texture: Loam fine subangular blocky structure; slightly hard, Depth class: Very deep (more than 60 inches) friable, slightly sticky, moderately plastic; common Drainage class: Well drained very fine and fine roots; many very fine and fine Dominant parent material: Material weathered from pores; few faint clay films on faces of peds; igneous rocks 30 percent pebbles; slightly acid. Native plant cover type: Rangeland Flooding: None Range in Characteristics Available water capacity: Mainly 8.1 inches Soil temperature: 36 to 41 degrees F Moisture control section: Between depths of 4 and A typical soil description with range in 12 inches characteristics is included, in alphabetical order, in Thickness of the mollic epipedon: 10 to 16 inches this section. Other features: The Monad soil is a taxadjunct to the Management series. It classifies as fine-loamy, mixed, superactive Typic Argicryolls. It does not meet the For management information about this map unit, requirements of Alfic Argicryolls but has similar see appropriate sections in Part II of this publication. use and management. A horizon Value: 3 or 4 dry; 2 or 3 moist 50D—Monad loam, 8 to 15 percent slopes Chroma: 1 or 2 Clay content: 20 to 27 percent Setting Content of rock fragments: 0 to 15 percent Landform: Hills pebbles Slope: 8 to 15 percent Reaction: pH 5.6 to 7.3 Elevation: 5,400 to 6,800 feet Bt horizons Mean annual precipitation: 18 to 22 inches Hue: 10YR or 7.5YR Frost-free period: 30 to 70 days Value: 5 to 7 dry; 4 or 5 moist Composition Chroma: 3 or 4 Texture: Clay loam, loam, or sandy clay loam Major Components Clay content: 22 to 35 percent Monad and similar soils: 85 percent Content of rock fragments: 15 to 35 percent Minor Components pebbles Soils that are very gravelly throughout: 0 to 8 percent Reaction: pH 5.6 to 7.8 Soils that have a clayey subsoil: 0 to 7 percent Major Component Description 50C—Monad loam, 2 to 8 percent slopes Surface layer texture: Loam Depth class: Very deep (more than 60 inches) Setting Drainage class: Well drained Landform: Hills Dominant parent material: Material weathered from Slope: 2 to 8 percent igneous rocks Elevation: 5,400 to 6,800 feet Native plant cover type: Rangeland Mean annual precipitation: 18 to 22 inches Flooding: None Frost-free period: 30 to 70 days Available water capacity: Mainly 8.1 inches Composition A typical soil description with range in Major Components characteristics is included, in alphabetical order, in Monad and similar soils: 85 percent this section. Powell County Area, Montana—Part I 143
Management Annual precipitation: 24 to 30 inches Annual air temperature: 35 to 38 degrees F For management information about this map unit, Frost-free period: 30 to 70 days see appropriate sections in Part II of this publication. Taxonomic Class: Sandy-skeletal, mixed Lamellic Cryorthents 50E—Monad loam, 15 to 35 percent slopes Typical Pedon Ovando very stony sandy loam, in an area of Elkner- Setting Ovando complex, 15 to 35 percent slopes, in an area of woodland, 1,400 feet south and 2,300 feet west of Landform: Hills the northeast corner of sec. 30, T. 13 N., R. 13 W. Slope: 15 to 35 percent Elevation: 5,400 to 6,800 feet Oi—3 to 0 inches; undecomposed and slightly Mean annual precipitation: 18 to 22 inches decomposed forest litter. Frost-free period: 30 to 70 days E1—0 to 5 inches; pale brown (10YR 6/3) very stony sandy loam, grayish brown (10YR 5/2) moist; Composition moderate very fine and fine granular structure; Major Components soft, very friable, nonsticky, nonplastic; many Monad and similar soils: 85 percent very fine and fine and common medium and coarse roots; common very fine and fine pores; Minor Components 20 percent stones, 10 percent cobbles, and Soils that are moderately deep to deep: 0 to 10 percent pebbles; slightly acid; clear wavy 5 percent boundary. Soils that are very gravelly throughout: 0 to 5 percent E2—5 to 16 inches; light gray (10YR 7/2) very stony Areas of rock outcrop: 0 to 5 percent loamy coarse sand, grayish brown (10YR 5/2) Major Component Description moist; weak fine granular structure; loose, nonsticky, nonplastic; many very fine and fine and Surface layer texture: Loam common medium and coarse roots; common very Depth class: Very deep (more than 60 inches) fine and fine pores; 10 percent stones, 20 percent Drainage class: Well drained cobbles, and 20 percent pebbles; moderately Dominant parent material: Material weathered from acid; clear wavy boundary. igneous rocks E and Bt—16 to 34 inches; 85 percent is pale brown Native plant cover type: Rangeland (10YR 6/3) very gravelly loamy coarse sand, Flooding: None brown (10YR 5/3) moist (E part); 15 percent is Available water capacity: Mainly 8.1 inches 1 brown (10YR 5/3) sandy loam lamellae /8- to 1 /4-inch thick, dark brown (10YR 4/3) moist A typical soil description with range in (B part); single grain; loose, nonsticky, nonplastic; characteristics is included, in alphabetical order, in many very fine and fine and few medium roots; this section. 10 percent stones, 10 percent cobbles, and Management 35 percent pebbles; slightly acid; gradual smooth boundary. For management information about this map unit, C—34 to 60 inches; pale brown (10YR 6/3) extremely see appropriate sections in Part II of this publication. gravelly loamy coarse sand, brown (10YR 5/3) moist; single grain; loose, nonsticky, nonplastic; Ovando Series few very fine, fine, and coarse roots; 10 percent stones, 15 percent cobbles, and 45 percent Depth class: Very deep pebbles; neutral. Drainage class: Excessively drained Range in Characteristics Permeability: Rapid Landform: Mountains Soil temperature: 37 to 44 degrees F Parent material: Granitic colluvium Moisture control section: Between depths of 12 and Slope range: 15 to 60 percent 35 inches; not dry in any part for as long as Elevation range: 4,600 to 7,000 feet 90 consecutive days 144 Soil Survey
E1 horizon Composition Value: 6 or 7 dry; 4 or 5 moist Major Components Chroma: 2 to 4 Ovando and similar soils: 50 percent Clay content: 5 to 10 percent Elkner and similar soils: 35 percent Content of rock fragments: 35 to 80 percent— 25 to 35 percent boulders, stones, and Minor Components cobbles; 10 to 45 percent pebbles Areas of rock outcrop: 0 to 5 percent Reaction: pH 5.6 to 6.5 Areas of rubble land: 0 to 5 percent Soils that have bouldery surface layers: 0 to 5 percent E2 horizon Hue: 10YR or 2.5Y Major Component Description Value: 6 or 7 dry; 4 or 5 moist Clay content: 0 to 5 percent Ovando Content of rock fragments: 15 to 80 percent—0 to Surface layer texture: Very stony sandy loam 40 percent boulders, stones, and cobbles; 5 to Depth class: Very deep (more than 60 inches) 45 percent pebbles Drainage class: Excessively drained Reaction: pH 5.6 to 6.5 Dominant parent material: Granitic colluvium Native plant cover type: Forestland E and Bt horizon Flooding: None Hue: E part—10YR or 2.5Y; B part—10YR or Available water capacity: Mainly 2.0 inches 2.5Y Value: E part—6 or 7 dry, 4 or 5 moist; B part— Elkner 4 or 5 dry, 4 or 5 moist Surface layer texture: Stony sandy loam Chroma: E part—2 to 4; B part—3 or 4 Depth class: Very deep (more than 60 inches) Clay content: 0 to 5 percent; lamellae have less Drainage class: Somewhat excessively drained than 3 percent clay increase Dominant parent material: Colluvium Content of rock fragments: 35 to 60 percent—0 to Native plant cover type: Forestland 40 percent stones or cobbles; 10 to 50 percent Flooding: None pebbles Available water capacity: Mainly 4.4 inches Reaction: pH 5.6 to 6.5 C horizon A typical soil description with range in Hue: 10YR or 2.5Y characteristics is included, in alphabetical order, in Value: 6 or 7 dry; 4 or 5 moist this section. Chroma: 2 to 4 Clay content: 0 to 5 percent Management Content of rock fragments: 60 to 80 percent—5 to For management information about this map unit, 40 percent stones and cobbles; 20 to 60 see appropriate sections in Part II of this publication. percent pebbles Reaction: pH 5.6 to 6.5 780E—Ovando-Elkner-Rock outcrop 180F—Ovando-Elkner complex, complex, 15 to 35 percent slopes 35 to 60 percent slopes Setting Setting Landform: Landform: • Ovando—Mountains • Ovando—Mountains • Elkner—Mountains • Elkner—Mountains • Rock outcrop—Mountains Slope: Slope: • Ovando—35 to 60 percent • Ovando—15 to 35 percent • Elkner—35 to 60 percent • Elkner—15 to 35 percent Elevation: 4,600 to 7,000 feet Elevation: 4,600 to 7,000 feet Mean annual precipitation: 24 to 30 inches Mean annual precipitation: 24 to 30 inches Frost-free period: 30 to 70 days Frost-free period: 30 to 70 days Powell County Area, Montana—Part I 145
Composition Elevation: 4,600 to 7,000 feet Mean annual precipitation: 24 to 30 inches Major Components Frost-free period: 30 to 70 days Ovando and similar soils: 40 percent Elkner and similar soils: 25 percent Composition Rock outcrop: 20 percent Major Components Minor Components Ovando and similar soils: 40 percent Yreka soils: 0 to 5 percent Elkner and similar soils: 25 percent Soils that are shallow to bedrock: 0 to 5 percent Rock outcrop: 20 percent Soils that have slopes more than 35 percent: 0 to Minor Components 5 percent Yreka soils: 0 to 8 percent Major Component Description Soils that are shallow to bedrock: 0 to 7 percent Ovando Major Component Description Surface layer texture: Extremely bouldery sandy loam Ovando Depth class: Very deep (more than 60 inches) Surface layer texture: Extremely bouldery sandy loam Drainage class: Excessively drained Depth class: Very deep (more than 60 inches) Dominant parent material: Granitic colluvium Drainage class: Excessively drained Native plant cover type: Forestland Dominant parent material: Granitic colluvium Flooding: None Native plant cover type: Forestland Available water capacity: Mainly 1.6 inches Flooding: None Available water capacity: Mainly 1.6 inches Elkner Surface layer texture: Bouldery sandy loam Elkner Depth class: Very deep (more than 60 inches) Surface layer texture: Bouldery sandy loam Drainage class: Somewhat excessively drained Depth class: Very deep (more than 60 inches) Dominant parent material: Colluvium Drainage class: Somewhat excessively drained Native plant cover type: Forestland Dominant parent material: Colluvium Flooding: None Native plant cover type: Forestland Available water capacity: Mainly 5.6 inches Flooding: None Available water capacity: Mainly 5.6 inches Rock outcrop Definition: Areas of exposed bedrock Rock outcrop Definition: Areas of exposed bedrock A typical soil description with range in characteristics is included, in alphabetical order, in A typical soil description with range in this section. characteristics is included, in alphabetical order, in Management this section. For management information about this map unit, Management see appropriate sections in Part II of this publication. For management information about this map unit, see appropriate sections in Part II of this publication. 780F—Ovando-Elkner-Rock outcrop complex, 35 to 60 percent slopes Perma Series Setting Depth class: Very deep Landform: Drainage class: Somewhat excessively drained • Ovando—Mountains Permeability: Moderate to BC horizon, moderately • Elkner—Mountains rapid below • Rock outcrop—Mountains Landform: Alluvial fans, stream terraces, moraines, Slope: and mountains • Ovando—35 to 60 percent Parent material: Alluvium, colluvium, and glacial • Elkner—35 to 60 percent outwash 146 Soil Survey
Slope range: 0 to 60 percent Range in Characteristics Elevation range: 3,800 to 5,000 feet Soil temperature: 44 to 47 degrees F Annual precipitation: 15 to 19 inches Moisture control section: Between depths of 8 and Annual air temperature: 39 to 44 degrees F 24 inches Frost-free period: 70 to 90 days Thickness of the mollic epipedon: 10 to 15 inches Depth to extremely gravelly material: 30 to 38 inches Taxonomic Class: Loamy-skeletal, mixed, superactive, frigid Typic Haplustolls A horizons Value: 4 or 5 dry; 2 or 3 moist Typical Pedon Chroma: 2 or 3 Perma gravelly loam, 0 to 4 percent slopes, in Clay content: 7 to 27 percent an area of irrigated hayland, 1,320 feet north and Content of rock fragments: 15 to 60 percent—0 to 800 feet east of the southwest corner of sec. 28, 30 percent boulders, stones, and cobbles; T. 15 N., R. 11 W. 10 to 50 percent pebbles Reaction: pH 6.6 to 7.3 Ap—0 to 5 inches; dark grayish brown (10YR 4/2) gravelly loam, very dark grayish brown (10YR Bw horizons 3/2) moist; moderate medium granular structure; Hue: 10YR or 7.5YR soft, very friable, nonsticky, slightly plastic; Value: 4 to 6 dry; 3 to 5 moist many very fine and fine and common medium Chroma: 2 to 4 roots; many very fine and fine irregular pores; Texture: Loam or sandy loam 20 percent pebbles; neutral; abrupt smooth Clay content: 7 to 27 percent boundary. Content of rock fragments: 35 to 85 percent—0 to A—5 to 10 inches; dark grayish brown (10YR 4/2) 50 percent stones and cobbles; 25 to gravelly loam, very dark grayish brown (10YR 65 percent pebbles 3/2) moist; moderate fine and medium granular Reaction: pH 6.6 to 7.8 structure; slightly hard, friable, nonsticky, slightly BC horizon plastic; many very fine and fine and few medium Hue: 10YR or 7.5YR roots; many very fine and fine irregular pores; Value: 4, 6, or 7 dry; 3 to 5 moist 20 percent pebbles; neutral; gradual wavy Chroma: 2 to 4 boundary. Texture: Loam, loamy sand, or sandy loam Bw1—10 to 17 inches; yellowish brown (10YR 5/4) Clay content: 0 to 15 percent very gravelly loam, dark brown (10YR 3/3) moist; Content of rock fragments: 60 to 85 percent— weak fine subangular blocky structure; slightly 10 to 50 percent stones and cobbles; 50 to hard, friable, slightly sticky, slightly plastic; 65 percent pebbles many very fine and fine and few medium roots; Reaction: pH 6.6 to 7.8 common fine tubular and irregular pores; 40 percent pebbles; neutral; gradual wavy boundary. Bw2—17 to 32 inches; dark yellowish brown (10YR 41B—Perma gravelly loam, 4/4) very gravelly loam, dark yellowish brown 0 to 4 percent slopes (10YR 3/4) moist; weak fine subangular blocky structure; soft, very friable, nonsticky, nonplastic; Setting common very fine and fine and few medium roots; many fine irregular pores; 5 percent stones, Landform: Alluvial fans and stream terraces 15 percent cobbles, and 35 percent pebbles; Slope: 0 to 4 percent neutral; gradual wavy boundary. Elevation: 3,800 to 5,000 feet BC—32 to 60 inches; dark yellowish brown (10YR Mean annual precipitation: 15 to 19 inches 4/4) extremely gravelly sandy loam, dark Frost-free period: 70 to 90 days yellowish brown (10YR 3/4) moist; single grain; loose, nonsticky, nonplastic; few very fine, fine, Composition and medium roots; many fine irregular pores; 5 percent stones, 15 percent cobbles, and Major Components 50 percent pebbles; neutral. Perma and similar soils: 85 percent Powell County Area, Montana—Part I 147
Minor Components A typical soil description with range in Perma cobbly loam: 0 to 5 percent characteristics is included, in alphabetical order, in Soils that have very gravelly clay subsoils: 0 to this section. 5 percent Management Soils that are loamy to 32 inches: 0 to 5 percent For management information about this map unit, Major Component Description see appropriate sections in Part II of this publication. Surface layer texture: Gravelly loam Depth class: Very deep (more than 60 inches) 41D—Perma gravelly loam, Drainage class: Somewhat excessively drained 8 to 15 percent slopes Dominant parent material: Alluvium Native plant cover type: Rangeland Setting Flooding: None Available water capacity: Mainly 4.2 inches Landform: Alluvial fans Slope: 8 to 15 percent A typical soil description with range in Elevation: 3,800 to 5,000 feet characteristics is included, in alphabetical order, in Mean annual precipitation: 15 to 19 inches this section. Frost-free period: 70 to 90 days Management Composition For management information about this map unit, Major Components see appropriate sections in Part II of this publication. Perma and similar soils: 85 percent Minor Components Soils that are very gravelly at 10 inches: 0 to 41C—Perma gravelly loam, 8 percent 4 to 8 percent slopes Soils that are very gravelly throughout: 0 to 7 percent Major Component Description Setting Surface layer texture: Gravelly loam Landform: Alluvial fans and stream terraces Depth class: Very deep (more than 60 inches) Slope: 4 to 8 percent Drainage class: Somewhat excessively drained Elevation: 3,800 to 5,000 feet Dominant parent material: Alluvium Mean annual precipitation: 15 to 19 inches Native plant cover type: Rangeland Frost-free period: 70 to 90 days Flooding: None Available water capacity: Mainly 4.2 inches Composition Major Components A typical soil description with range in Perma and similar soils: 85 percent characteristics is included, in alphabetical order, in this section. Minor Components Perma stony loam: 0 to 8 percent Management Soils that are very gravelly at 10 inches: 0 to For management information about this map unit, 7 percent see appropriate sections in Part II of this publication. Major Component Description Surface layer texture: Gravelly loam 41E—Perma gravelly loam, Depth class: Very deep (more than 60 inches) 15 to 35 percent slopes Drainage class: Somewhat excessively drained Dominant parent material: Alluvium Setting Native plant cover type: Rangeland Flooding: None Landform: Alluvial fans Available water capacity: Mainly 4.2 inches Slope: 15 to 35 percent 148 Soil Survey
Elevation: 3,800 to 5,000 feet Major Component Description Mean annual precipitation: 15 to 19 inches Surface layer texture: Gravelly loam Frost-free period: 70 to 90 days Depth class: Very deep (more than 60 inches) Composition Drainage class: Somewhat excessively drained Dominant parent material: Alluvium or colluvium Major Components Native plant cover type: Rangeland Perma and similar soils: 85 percent Flooding: None Minor Components Available water capacity: Mainly 4.2 inches Soils that are loamy throughout: 0 to 5 percent Soils that have very gravelly clay subsoils: 0 to A typical soil description with range in 4 percent characteristics is included, in alphabetical order, in Areas of rock outcrop: 0 to 3 percent this section. Shallow soils that are near rock areas: 0 to 3 percent Management Major Component Description For management information about this map unit, Surface layer texture: Gravelly loam see appropriate sections in Part II of this publication. Depth class: Very deep (more than 60 inches) Drainage class: Somewhat excessively drained Dominant parent material: Alluvium or colluvium 241B—Perma stony loam, Native plant cover type: Rangeland 0 to 4 percent slopes Flooding: None Available water capacity: Mainly 4.2 inches Setting Landform: Alluvial fans and stream terraces A typical soil description with range in Slope: 0 to 4 percent characteristics is included, in alphabetical order, in Elevation: 3,800 to 5,000 feet this section. Mean annual precipitation: 15 to 19 inches Management Frost-free period: 70 to 90 days For management information about this map unit, Composition see appropriate sections in Part II of this publication. Major Components Perma and similar soils: 85 percent 41F—Perma gravelly loam, Minor Components 35 to 60 percent slopes Soils that are calcareous throughout: 0 to 8 percent Soils that are loamy sand below 10 inches: 0 to Setting 7 percent Landform: Alluvial fans Major Component Description Slope: 35 to 60 percent Surface layer texture: Stony loam Elevation: 3,800 to 5,000 feet Depth class: Very deep (more than 60 inches) Mean annual precipitation: 15 to 19 inches Drainage class: Somewhat excessively drained Frost-free period: 70 to 90 days Dominant parent material: Alluvium Composition Native plant cover type: Rangeland Flooding: None Major Components Available water capacity: Mainly 3.5 inches Perma and similar soils: 85 percent Minor Components A typical soil description with range in Areas of rock outcrop: 0 to 10 percent characteristics is included, in alphabetical order, in Shallow soils that are near rock areas: 0 to 5 percent this section. Powell County Area, Montana—Part I 149
Management Composition For management information about this map unit, Major Components see appropriate sections in Part II of this publication. Perma and similar soils: 85 percent Minor Components 241C—Perma stony loam, Soils that are calcareous throughout: 0 to 8 percent 4 to 8 percent slopes Soils that are loamy sand below 10 inches: 0 to 7 percent Setting Major Component Description Landform: Alluvial fans and stream terraces Surface layer texture: Stony loam Slope: 4 to 8 percent Depth class: Very deep (more than 60 inches) Elevation: 3,800 to 5,000 feet Drainage class: Somewhat excessively drained Mean annual precipitation: 15 to 19 inches Dominant parent material: Alluvium Frost-free period: 70 to 90 days Native plant cover type: Rangeland Flooding: None Composition Available water capacity: Mainly 3.5 inches Major Components Perma and similar soils: 85 percent A typical soil description with range in characteristics is included, in alphabetical order, in Minor Components this section. Soils that are calcareous throughout: 0 to 8 percent Soils that are loamy sand below 10 inches: 0 to Management 7 percent For management information about this map unit, Major Component Description see appropriate sections in Part II of this publication. Surface layer texture: Stony loam Depth class: Very deep (more than 60 inches) 241E—Perma stony loam, Drainage class: Somewhat excessively drained 15 to 35 percent slopes Dominant parent material: Alluvium Native plant cover type: Rangeland Setting Flooding: None Available water capacity: Mainly 3.5 inches Landform: Mountains Slope: 15 to 35 percent A typical soil description with range in Elevation: 3,800 to 5,000 feet characteristics is included, in alphabetical order, in Mean annual precipitation: 15 to 19 inches this section. Frost-free period: 70 to 90 days Management Composition For management information about this map unit, Major Components see appropriate sections in Part II of this publication. Perma and similar soils: 85 percent Minor Components 241D—Perma stony loam, Soils that are calcareous throughout: 0 to 10 percent 8 to 15 percent slopes Soils that are loamy sand below 10 inches: 0 to 5 percent Setting Major Component Description Landform: Alluvial fans Surface layer texture: Stony loam Slope: 8 to 15 percent Depth class: Very deep (more than 60 inches) Elevation: 3,800 to 5,000 feet Drainage class: Somewhat excessively drained Mean annual precipitation: 15 to 19 inches Dominant parent material: Alluvium Frost-free period: 70 to 90 days Native plant cover type: Rangeland 150 Soil Survey
Flooding: None 338D—Perma cobbly loam, Available water capacity: Mainly 3.5 inches 8 to 15 percent slopes A typical soil description with range in Setting characteristics is included, in alphabetical order, in this section. Landform: Alluvial fans Slope: 8 to 15 percent Management Elevation: 3,800 to 5,000 feet For management information about this map unit, Mean annual precipitation: 15 to 19 inches see appropriate sections in Part II of this publication. Frost-free period: 70 to 90 days Composition 338C—Perma cobbly loam, Major Components 4 to 8 percent slopes Perma and similar soils: 85 percent Minor Components Setting Very gravelly sandy soils: 0 to 5 percent Landform: Alluvial fans and stream terraces Soils that have slopes more than 8 percent: 0 to Slope: 4 to 8 percent 5 percent Elevation: 3,800 to 5,000 feet Soils that are calcareous at 10 inches: 0 to 5 percent Mean annual precipitation: 15 to 19 inches Major Component Description Frost-free period: 70 to 90 days Surface layer texture: Cobbly loam Composition Depth class: Very deep (more than 60 inches) Major Components Drainage class: Somewhat excessively drained Perma and similar soils: 85 percent Dominant parent material: Alluvium Native plant cover type: Rangeland Minor Components Flooding: None Very gravelly sandy soils: 0 to 5 percent Available water capacity: Mainly 4.2 inches Soils that have slopes more than 8 percent: 0 to 5 percent A typical soil description with range in Soils that are calcareous at 10 inches: 0 to 5 percent characteristics is included, in alphabetical order, in Major Component Description this section. Surface layer texture: Cobbly loam Management Depth class: Very deep (more than 60 inches) For management information about this map unit, Drainage class: Somewhat excessively drained see appropriate sections in Part II of this publication. Dominant parent material: Alluvium Native plant cover type: Rangeland Flooding: None 338E—Perma cobbly loam, Available water capacity: Mainly 4.2 inches 15 to 35 percent slopes A typical soil description with range in Setting characteristics is included, in alphabetical order, in this section. Landform: Mountains Slope: 15 to 35 percent Management Elevation: 3,800 to 5,000 feet For management information about this map unit, Mean annual precipitation: 15 to 19 inches see appropriate sections in Part II of this publication. Frost-free period: 70 to 90 days Powell County Area, Montana—Part I 151
Composition Major Component Description Major Components Surface layer texture: Cobbly loam Perma and similar soils: 85 percent Depth class: Very deep (more than 60 inches) Drainage class: Somewhat excessively drained Minor Components Dominant parent material: Alluvium Very gravelly sandy soils: 0 to 5 percent Native plant cover type: Rangeland Soils that have slopes more than 8 percent: 0 to Flooding: None 4 percent Available water capacity: Mainly 4.2 inches Soils that are calcareous at 10 inches: 0 to 3 percent Soils that have a very cobbly surface: 0 to 3 percent A typical soil description with range in Major Component Description characteristics is included, in alphabetical order, in this section. Surface layer texture: Cobbly loam Depth class: Very deep (more than 60 inches) Management Drainage class: Somewhat excessively drained For management information about this map unit, Dominant parent material: Alluvium see appropriate sections in Part II of this publication. Native plant cover type: Rangeland Flooding: None Available water capacity: Mainly 4.2 inches 542E—Perma very bouldery loam, 8 to 25 percent slopes A typical soil description with range in characteristics is included, in alphabetical order, in Setting this section. Landform: Moraines Management Slope: 8 to 25 percent Elevation: 3,800 to 5,000 feet For management information about this map unit, Mean annual precipitation: 15 to 19 inches see appropriate sections in Part II of this publication. Frost-free period: 70 to 90 days Composition 338F—Perma cobbly loam, 35 to 60 percent slopes Major Components Perma and similar soils: 85 percent Setting Minor Components Shawmut soils: 0 to 6 percent Landform: Mountains Soils that have slopes more than 25 percent: 0 to Slope: 35 to 60 percent 6 percent Elevation: 3,800 to 5,000 feet Areas of open water: 0 to 3 percent Mean annual precipitation: 15 to 19 inches Frost-free period: 70 to 90 days Major Component Description Composition Surface layer texture: Very bouldery loam Depth class: Very deep (more than 60 inches) Major Components Drainage class: Somewhat excessively drained Perma and similar soils: 85 percent Dominant parent material: Glacial outwash Minor Components Flooding: None Very gravelly sandy soils: 0 to 5 percent Available water capacity: Mainly 3.7 inches Soils that have slopes more than 8 percent: 0 to 4 percent A typical soil description with range in Soils that are calcareous at 10 inches: 0 to 3 percent characteristics is included, in alphabetical order, in Soils that have a very cobbly surface: 0 to 3 percent this section. 152 Soil Survey
Management Composition For management information about this map unit, Major Components see appropriate sections in Part II of this publication. Perma and similar soils: 85 percent Minor Components 542F—Perma very bouldery loam, Very gravelly sandy soils: 0 to 5 percent 25 to 50 percent slopes Straw soils: 0 to 5 percent Poorly drained soils: 0 to 3 percent Areas of open water: 0 to 2 percent Setting Major Component Description Landform: Moraines Slope: 25 to 50 percent Surface layer texture: Extremely bouldery loam Elevation: 3,800 to 5,000 feet Depth class: Very deep (more than 60 inches) Mean annual precipitation: 15 to 19 inches Drainage class: Somewhat excessively drained Frost-free period: 70 to 90 days Dominant parent material: Glacial outwash Native plant cover type: Rangeland Composition Flooding: None Major Components Available water capacity: Mainly 3.6 inches Perma and similar soils: 85 percent A typical soil description with range in Minor Components characteristics is included, in alphabetical order, in Shawmut soils: 0 to 6 percent this section. Soils that have slopes more than 50 percent: 0 to 6 percent Management Areas of open water: 0 to 3 percent For management information about this map unit, Major Component Description see appropriate sections in Part II of this publication. Surface layer texture: Very bouldery loam Depth class: Very deep (more than 60 inches) 838E—Perma-Whitlash-Rock outcrop Drainage class: Somewhat excessively drained complex, 15 to 35 percent slopes Dominant parent material: Glacial outwash Flooding: None Setting Available water capacity: Mainly 3.7 inches Landform: A typical soil description with range in • Perma—Mountains characteristics is included, in alphabetical order, in • Whitlash—Mountains this section. • Rock outcrop—Mountains Slope: Management • Perma—15 to 35 percent For management information about this map unit, • Whitlash—15 to 35 percent see appropriate sections in Part II of this publication. Elevation: 3,800 to 5,000 feet Mean annual precipitation: 15 to 19 inches Frost-free period: 70 to 90 days 642E—Perma extremely bouldery loam, 8 to 50 percent slopes Composition Major Components Setting Perma and similar soils: 50 percent Whitlash and similar soils: 20 percent Landform: Moraines Rock outcrop: 15 percent Slope: 8 to 50 percent Elevation: 3,800 to 5,000 feet Minor Components Mean annual precipitation: 15 to 19 inches Soils that have slopes more than 60 percent: 0 to Frost-free period: 70 to 90 days 15 percent Powell County Area, Montana—Part I 153
Major Component Description Major Component Description Perma Perma Surface layer texture: Gravelly loam Surface layer texture: Gravelly loam Depth class: Very deep (more than 60 inches) Depth class: Very deep (more than 60 inches) Drainage class: Somewhat excessively drained Drainage class: Somewhat excessively drained Dominant parent material: Colluvium Dominant parent material: Colluvium Native plant cover type: Rangeland Native plant cover type: Rangeland Flooding: None Flooding: None Available water capacity: Mainly 4.2 inches Available water capacity: Mainly 4.2 inches
Whitlash Whitlash Surface layer texture: Very stony loam Surface layer texture: Very stony loam Depth class: Shallow (10 to 20 inches) Depth class: Shallow (10 to 20 inches) Drainage class: Well drained Drainage class: Well drained Dominant parent material: Igneous residuum Dominant parent material: Igneous residuum Flooding: None Native plant cover type: Rangeland Available water capacity: Mainly 1.3 inches Flooding: None Available water capacity: Mainly 1.3 inches Rock outcrop Definition: Areas of exposed bedrock Rock outcrop Definition: Areas of exposed bedrock A typical soil description with range in characteristics is included, in alphabetical order, in A typical soil description with range in this section. characteristics is included, in alphabetical order, in this section. Management Management For management information about this map unit, see appropriate sections in Part II of this publication. For management information about this map unit, see appropriate sections in Part II of this publication. 838F—Perma-Whitlash-Rock outcrop complex, 35 to 60 percent slopes 102—Pits, gravel
Setting Composition Landform: Major Components • Perma—Mountains Pits, gravel: 85 percent • Whitlash—Mountains Minor Components • Rock outcrop—Mountains Areas of soils that support vegetation: 0 to 15 percent Slope: • Perma—35 to 60 percent Major Component Description • Whitlash—35 to 60 percent Definition: Areas mined as a source of sand and Elevation: 3,800 to 5,000 feet gravel, supporting little or no vegetation Mean annual precipitation: 15 to 19 inches Flooding: None Frost-free period: 70 to 90 days Composition Major Components Poronto Series Perma and similar soils: 50 percent Depth class: Very deep Whitlash and similar soils: 20 percent Drainage class: Poorly drained Rock outcrop: 15 percent Permeability: Moderate Minor Components Landform: Flood plains and stream terraces Soils that have slopes more than 60 percent: 0 to Parent material: Alluvium 15 percent Slope range: 0 to 4 percent 154 Soil Survey
Elevation range: 3,800 to 5,800 feet Thickness of the mollic epipedon: 10 to 16 inches Annual precipitation: 10 to 19 inches Depth to the seasonal high water table: 12 to Annual air temperature: 39 to 44 degrees F 24 inches Frost-free period: 70 to 105 days A horizon Hue: 10YR or 2.5Y Taxonomic Class: Loamy-skeletal, mixed, Value: 2 or 3 moist; 2 to 5 dry superactive, frigid Typic Endoaquolls Chroma: 0 to 2 Typical Pedon Clay content: 18 to 27 percent Content of rock fragments: 0 to 15 percent—0 to Poronto loam, 0 to 4 percent slopes, in an area of 5 percent cobbles; 0 to 10 percent pebbles pasture, 1,900 feet south and 350 feet east of the Reaction: pH 6.6 to 7.8 northwest corner of sec. 11, T. 6 N., R. 10 W. Bg1 horizon Oi—3 inches to 0; slightly decomposed organic Hue: 5YR, 7.5YR, 10YR, 2.5Y, or 5Y matter. Value: 3 or 4 moist; 4 to 7 dry A—0 to 10 inches; very dark gray (10YR 3/1) loam, Chroma: 1 to 3 grayish brown (10YR 5/2) dry; common fine Texture: Loam, clay loam, sandy clay loam, or distinct strong brown (7.5YR 5/8) redox silty clay loam concentrations; moderate medium granular Clay content: 18 to 35 percent structure; very hard, firm, moderately sticky and Content of rock fragments: 35 to 60 percent—0 to slightly plastic; many very fine and fine roots; 10 percent cobbles; 35 to 50 percent pebbles many very fine and fine interstitial pores; slightly Reaction: pH 6.6 to 7.8 effervescent; slightly alkaline; clear smooth boundary. Bg2 horizon Bg1—10 to 16 inches; dark gray (5YR 4/1) very Hue: 5YR, 7.5YR, 10YR, 2.5Y, or 5Y gravelly silty clay loam, light gray (5YR 7/1) dry; Value: 3 to 5 moist; 5 to 7 dry many medium distinct strong brown (7.5YR 5/8) Chroma: 1 to 3 redox concentrations; weak medium subangular Texture: Clay loam, sandy clay loam, or loam blocky structure; very hard, friable, slightly sticky, Clay content: 18 to 35 percent slightly plastic; many very fine and fine roots; Content of rock fragments: 35 to 60 percent—0 to many very fine and fine interstitial pores; 20 percent cobbles; 35 to 40 percent pebbles 40 percent pebbles; slightly alkaline; gradual Reaction: pH 6.6 to 7.8 wavy boundary. Bg3 horizon Bg2—16 to 28 inches; dark gray (5YR 4/1) very Hue: 5YR, 7.5YR, 10YR, 2.5Y, or 5Y gravelly clay loam, light gray (5YR 7/1) dry; many Value: 3 to 5 moist; 4 to 7 dry fine distinct yellowish red (5YR 4/6) redox Chroma: 1 or 2 concentrations; weak medium subangular blocky Texture: Sandy loam or sandy clay loam structure; hard, friable, slightly sticky, moderately Clay content: 18 to 30 percent plastic; common very fine and fine roots; many Content of rock fragments: 35 to 60 percent—0 to very fine and fine interstitial pores; 40 percent 15 percent cobbles; 35 to 45 percent pebbles pebbles; neutral; gradual wavy boundary. Reaction: pH 6.6 to 7.3 Bg3—28 to 60 inches; dark gray (5YR 4/1) very gravelly sandy loam, light gray (5YR 6/1) dry; few fine distinct strong brown (7.5YR 5/8) redox concentrations; weak medium subangular blocky 637—Poronto loam, 0 to 4 percent slopes structure; soft, very friable, nonsticky, nonplastic; few very fine and fine roots; many very fine and Setting fine irregular pores; 45 percent pebbles; neutral. Landform: Stream terraces Range in Characteristics Slope: 0 to 4 percent Soil temperature: 41 to 46 degrees F Elevation: 3,800 to 5,800 feet Moisture control section: Between depths of 4 and Mean annual precipitation: 10 to 19 inches 12 inches Frost-free period: 70 to 105 days Powell County Area, Montana—Part I 155
Composition Dominant parent material: Alluvium Native plant cover type: Rangeland Major Components Flooding: Rare Poronto and similar soils: 85 percent Water table: Apparent Minor Components Available water capacity: Mainly 6.1 inches Very poorly drained soils: 0 to 3 percent Blossberg soils: 0 to 3 percent A typical soil description with range in Soils that are gravelly in upper layers: 0 to 3 percent characteristics is included, in alphabetical order, in Soils that are calcareous throughout: 0 to 3 percent this section. Kleinschmidt soils: 0 to 3 percent Management Major Component Description For management information about this map unit, Surface layer texture: Loam see appropriate sections in Part II of this publication. Depth class: Very deep (more than 60 inches) Drainage class: Poorly drained Dominant parent material: Alluvium Quigley Series Native plant cover type: Rangeland Depth class: Very deep Flooding: None Drainage class: Well drained Water table: Apparent Permeability: Moderate Available water capacity: Mainly 6.1 inches Landform: Alluvial fans, stream terraces, and moraines A typical soil description with range in Parent material: Calcareous alluvium and alpine till characteristics is included, in alphabetical order, in Slope range: 0 to 25 percent this section. Elevation range: 3,800 to 5,800 feet Management Annual precipitation: 15 to 19 inches Annual air temperature: 38 to 44 degrees F For management information about this map unit, Frost-free period: 70 to 90 days see appropriate sections in Part II of this publication. Taxonomic Class: Fine-loamy, mixed, superactive, 837—Poronto loam, 0 to 4 percent slopes, frigid Typic Haplustolls rarely flooded Typical Pedon Quigley loam, 0 to 4 percent slopes, in an area of Setting rangeland, 100 feet south and 350 feet west of the Landform: Flood plains northeast corner of sec. 35, T. 7 N., R. 9 W. Slope: 0 to 4 percent A—0 to 3 inches; dark grayish brown (10YR 4/2) Elevation: 3,800 to 5,800 feet loam, very dark grayish brown (10YR 3/2) moist; Mean annual precipitation: 10 to 19 inches weak thin platy structure parting to weak fine Frost-free period: 70 to 105 days granular structure; slightly hard, very friable, Composition slightly sticky, slightly plastic; many very fine roots; many very fine and fine tubular pores; Major Components 5 percent pebbles; neutral; clear wavy boundary. Poronto and similar soils: 85 percent Bw—3 to 10 inches; brown (10YR 4/3) clay loam, Minor Components dark brown (10YR 3/3) moist; weak medium Very gravelly sandy soils: 0 to 4 percent prismatic structure parting to moderate fine and Blossberg soils: 0 to 4 percent medium subangular blocky; hard, friable, Very poorly drained soils: 0 to 4 percent moderately sticky and moderately plastic; many Kleinschmidt soils: 0 to 3 percent fine roots; many very fine and fine tubular pores; 5 percent pebbles; neutral; clear wavy boundary. Major Component Description Bk1—10 to 13 inches; pale brown (10YR 6/3) loam, Surface layer texture: Loam brown (10YR 5/3) moist; moderate fine and Depth class: 80 medium subangular blocky structure; hard, Drainage class: Poorly drained friable, slightly sticky, slightly plastic; many fine 156 Soil Survey
roots; common fine irregular and few fine tubular Bk1 horizon pores; 5 percent pebbles; many fine and medium Value: 6 or 7 dry; 5 moist masses of lime; strongly effervescent; moderately Chroma: 3 alkaline; clear wavy boundary. Texture: Loam or clay loam Bk2—13 to 23 inches; white (10YR 8/1) gravelly Clay content: 15 to 30 percent loam, light gray (10YR 7/2) moist; weak fine Content of rock fragments: 5 to 35 percent—0 to subangular blocky structure; slightly hard, very 20 percent cobbles; 5 to 15 percent pebbles friable, slightly sticky, slightly plastic; common Calcium carbonate equivalent: 15 to 40 percent fine roots; many fine tubular and irregular pores; Reaction: pH 7.9 to 8.4 5 percent cobbles and 10 percent pebbles; Bk2 horizon disseminated lime; continuous faint coatings of Value: 7 or 8 dry; 6 or 7 moist lime on rock fragments; violently effervescent; Chroma: 1 to 3 moderately alkaline; gradual wavy boundary. Texture: Loam or clay loam Bk3—23 to 45 inches; light gray (2.5Y 7/2) gravelly Clay content: 15 to 30 percent loam, light yellowish brown (2.5Y 6/4) moist; Content of rock fragments: 10 to 35 percent—5 to weak fine subangular blocky structure; slightly 20 percent cobbles; 5 to 15 percent pebbles hard, very friable, slightly sticky, slightly plastic; Calcium carbonate equivalent: 15 to 40 percent few fine roots; many very fine and fine irregular Reaction: pH 7.9 to 8.4 and common fine tubular pores; 5 percent cobbles and 15 percent pebbles; disseminated Bk3 horizon lime; continuous faint coatings of lime on rock Hue: 10YR or 2.5Y fragments; violently effervescent; moderately Value: 6 or 7 dry; 5 or 6 moist alkaline; gradual wavy boundary. Chroma: 2 to 4 2Bk4—45 to 60 inches; very pale brown (10YR 7/3) Texture: Loam, clay loam, or sandy loam very cobbly sandy loam, pale brown (10YR 6/3) Clay content: 15 to 30 percent moist; weak fine subangular blocky structure; Content of rock fragments: 10 to 35 percent—5 to soft, very friable, nonsticky, slightly plastic; many 20 percent cobbles; 5 to 15 percent pebbles fine irregular pores; 20 percent cobbles and Calcium carbonate equivalent: 15 to 35 percent 20 percent pebbles; disseminated lime; Reaction: pH 7.9 to 8.4 continuous faint coatings of lime on undersides of 2Bk4 horizon rock fragments; violently effervescent; moderately Hue: 10YR or 2.5Y alkaline. Value: 6 or 7 dry; 5 or 6 moist Range in Characteristics Chroma: 2 or 3 Texture: Loam or sandy loam Soil temperature: 40 to 46 degrees F Clay content: 10 to 20 percent Moisture control section: Between depths of 4 and Content of rock fragments: 30 to 50 percent— 12 inches 15 to 25 percent cobbles; 15 to 25 percent Thickness of the mollic epipedon: 7 to 15 inches pebbles (includes the Bw horizon) Calcium carbonate equivalent: 10 to 20 percent Depth to the Bk horizon: 7 to 15 inches Reaction: pH 7.9 to 9.0 A horizon Value: 4 or 5 dry; 2 or 3 moist Chroma: 2 or 3 60B—Quigley loam, 0 to 4 percent slopes Clay content: 20 to 27 percent Content of rock fragments: 0 to 35 percent—0 to Setting 20 percent cobbles; 0 to 15 percent pebbles Landform: Alluvial fans and stream terraces Reaction: pH 6.6 to 7.3 Slope: 0 to 4 percent Bw horizon Elevation: 3,800 to 5,800 feet Value: 4 or 5 dry; 3 moist Mean annual precipitation: 15 to 19 inches Texture: Loam or clay loam Frost-free period: 70 to 90 days Clay content: 18 to 33 percent Composition Content of rock fragments: 5 to 35 percent—0 to 20 percent cobbles; 5 to 15 percent pebbles Major Components Reaction: pH 6.6 to 7.3 Quigley and similar soils: 85 percent Powell County Area, Montana—Part I 157
Minor Components Native plant cover type: Rangeland Soils that slopes more than 4 percent: 0 to 4 percent Flooding: None Soils that are very gravelly throughout: 0 to 4 percent Available water capacity: Mainly 7.1 inches Soils that have a calcareous surface layer: 0 to 4 percent A typical soil description with range in Quigley gravelly loam: 0 to 3 percent characteristics is included, in alphabetical order, in this section. Major Component Description Management Surface layer texture: Loam Depth class: Very deep (more than 60 inches) For management information about this map unit, Drainage class: Well drained see appropriate sections in Part II of this publication. Dominant parent material: Alluvium Native plant cover type: Rangeland Flooding: None 60D—Quigley loam, 8 to 15 percent Available water capacity: Mainly 7.1 inches slopes
A typical soil description with range in Setting characteristics is included, in alphabetical order, in Landform: Alluvial fans this section. Slope: 8 to 15 percent Management Elevation: 3,800 to 5,800 feet Mean annual precipitation: 15 to 19 inches For management information about this map unit, Frost-free period: 70 to 90 days see appropriate sections in Part II of this publication. Composition 60C—Quigley loam, 4 to 8 percent slopes Major Components Quigley and similar soils: 85 percent Setting Minor Components Soils that have slopes more than 15 percent: 0 to Landform: Alluvial fans and stream terraces 4 percent Slope: 4 to 8 percent Soils that are very gravelly throughout: 0 to 4 percent Elevation: 3,800 to 5,800 feet Soils that have a calcareous surface layer: 0 to Mean annual precipitation: 15 to 19 inches 4 percent Frost-free period: 70 to 90 days Soils that have a gravelly, cobbly surface: 0 to Composition 3 percent Major Components Major Component Description Quigley and similar soils: 85 percent Surface layer texture: Loam Minor Components Depth class: Very deep (more than 60 inches) Soils that have slopes more than 8 percent: 0 to Drainage class: Well drained 4 percent Dominant parent material: Alluvium Soils that are very gravelly throughout: 0 to 4 percent Native plant cover type: Rangeland Soils that have a calcareous surface layer: 0 to Flooding: None 4 percent Available water capacity: Mainly 7.1 inches Soils that have a gravelly, cobbly surface: 0 to 3 percent A typical soil description with range in characteristics is included, in alphabetical order, in Major Component Description this section. Surface layer texture: Loam Management Depth class: Very deep (more than 60 inches) Drainage class: Well drained For management information about this map unit, Dominant parent material: Alluvium see appropriate sections in Part II of this publication. 158 Soil Survey
63C—Quigley-Straw-Water complex, 63E—Quigley-Straw-Water complex, 2 to 8 percent slopes 8 to 25 percent slopes
Setting Setting Landform: Landform: • Quigley—Moraines • Quigley—Moraines • Straw—Drainageways • Straw—Drainageways Slope: Slope: • Quigley—2 to 8 percent • Quigley—8 to 25 percent • Straw—2 to 8 percent • Straw—8 to 25 percent Elevation: 3,800 to 5,800 feet Elevation: 3,800 to 5,800 feet Mean annual precipitation: 15 to 19 inches Mean annual precipitation: 15 to 19 inches Frost-free period: 70 to 90 days Frost-free period: 70 to 90 days Composition Composition Major Components Major Components Quigley and similar soils: 55 percent Quigley and similar soils: 55 percent Straw and similar soils: 20 percent Straw and similar soils: 20 percent Water: 10 percent Water: 10 percent Minor Components Minor Components Soils that have silt loam below 8 inches: 0 to Soils that are very gravelly throughout: 0 to 15 percent 15 percent Major Component Description Major Component Description Quigley Quigley Surface layer texture: Loam Surface layer texture: Loam Depth class: Very deep (more than 60 inches) Depth class: Very deep (more than 60 inches) Drainage class: Well drained Drainage class: Well drained Dominant parent material: Alpine till Dominant parent material: Alpine till Native plant cover type: Rangeland Native plant cover type: Rangeland Flooding: None Flooding: None Available water capacity: Mainly 7.1 inches Available water capacity: Mainly 7.1 inches Straw Straw Surface layer texture: Loam Surface layer texture: Loam Depth class: Very deep (more than 60 inches) Depth class: Very deep (more than 60 inches) Drainage class: Well drained Drainage class: Well drained Dominant parent material: Alpine till Dominant parent material: Alpine till Native plant cover type: Rangeland Native plant cover type: Rangeland Flooding: None Flooding: None Available water capacity: Mainly 10.6 inches Available water capacity: Mainly 10.6 inches Water Water Definition: Areas of open water Definition: Areas of open water A typical soil description with range in A typical soil description with range in characteristics is included, in alphabetical order, in characteristics is included, in alphabetical order, in this section. this section. Management Management For management information about this map unit, For management information about this map unit, see appropriate sections in Part II of this publication. see appropriate sections in Part II of this publication. Powell County Area, Montana—Part I 159
460C—Quigley cobbly loam, Typical Pedon 4 to 8 percent slopes Redchief gravelly loam, in an area of Redchief- Copenhaver gravelly loams, 8 to 15 percent slopes, in Setting an area of rangeland, 1,900 feet north and 50 feet west of the southeast corner of sec. 3, T. 10 N., Landform: Alluvial fans and stream terraces R. 6 W. Slope: 4 to 8 percent Elevation: 3,800 to 5,800 feet A—0 to 10 inches; very dark grayish brown (10YR Mean annual precipitation: 15 to 19 inches 3/2) gravelly loam, very dark brown (10YR 2/2) Frost-free period: 70 to 90 days moist; weak fine subangular blocky structure; soft, very friable, slightly sticky, slightly plastic; Composition many very fine and fine and common medium Major Components roots; many very fine and fine interstitial pores; Quigley and similar soils: 85 percent 5 percent cobbles and 20 percent pebbles; moderately acid; clear wavy boundary. Minor Components Bt1—10 to 18 inches; yellowish brown (10YR 5/4) Shawmut soils: 0 to 8 percent very gravelly clay loam, dark yellowish brown Winspect soils: 0 to 7 percent (10YR 4/4) moist; moderate fine subangular Major Component Description blocky structure; hard, friable, slightly sticky, moderately plastic; common very fine and fine Surface layer texture: Cobbly loam and few medium and coarse roots; many very Depth class: Very deep (more than 60 inches) fine, fine, and medium interstitial pores; many Drainage class: Well drained faint clay films on faces of peds; 15 percent Dominant parent material: Alluvium cobbles and 35 percent pebbles; slightly acid; Native plant cover type: Rangeland clear wavy boundary. Flooding: None Bt2—18 to 28 inches; light yellowish brown (10YR Available water capacity: Mainly 6.0 inches 6/4) very gravelly clay loam, yellowish brown (10YR 5/4) moist; moderate medium subangular A typical soil description with range in blocky structure; very hard, friable, moderately characteristics is included, in alphabetical order, in sticky and moderately plastic; few very fine and this section. fine roots; common very fine and fine interstitial Management pores; many faint clay films on faces of peds; 20 percent cobbles and 35 percent pebbles; For management information about this map unit, neutral; gradual wavy boundary. see appropriate sections in Part II of this publication. Bt3—28 to 60 inches; pale brown (10YR 6/3) extremely gravelly clay loam, dark yellowish brown (10YR 4/4) moist; moderate medium Redchief Series subangular blocky structure; very hard, friable, moderately sticky and moderately plastic; few Depth class: Very deep very fine and fine roots; few very fine and fine Drainage class: Well drained interstitial pores; many faint clay films on faces Permeability: Slow of peds; 20 percent cobbles and 45 percent Landform: Mountains and hills pebbles; neutral. Parent material: Colluvium derived from igneous bedrock Range in Characteristics Slope range: 4 to 60 percent Soil temperature: 36 to 45 degrees F Elevation range: 5,000 to 8,600 feet Moisture control section: Between depths of 4 and Annual precipitation: 18 to 22 inches 12 inches Annual air temperature: 34 to 39 degrees F Thickness of the mollic epipedon: 10 to 16 inches Frost-free period: 30 to 70 days A horizon Taxonomic Class: Clayey-skeletal, smectitic Ustic Hue: 10YR or 7.5YR Argicryolls Value: 2 to 4 dry; 2 or 3 moist 160 Soil Survey
Chroma: 2 or 3 Minor Components Clay content: 20 to 27 percent Soils that are moderately deep to deep: 0 to Content of rock fragments: 15 to 35 percent—0 to 10 percent 25 percent stones and cobbles; 15 to Areas of rock outcrop: 0 to 5 percent 25 percent pebbles Major Component Description Reaction: pH 5.1 to 6.0 Surface layer texture: Cobbly loam Bt1 horizon Depth class: Very deep (more than 60 inches) Hue: 5YR, 7.5YR, or 10YR Drainage class: Well drained Value: 4 or 5 dry; 3 or 4 moist Dominant parent material: Igneous colluvium Chroma: 3, 4, 6, or 8 Native plant cover type: Rangeland Texture: Clay loam or clay Flooding: None Clay content: 35 to 50 percent Available water capacity: Mainly 5.4 inches Content of rock fragments: 25 to 60 percent—0 to 20 percent stones and cobbles; 25 to A typical soil description with range in 50 percent pebbles characteristics is included, in alphabetical order, in Reaction: pH 5.1 to 6.0 this section. Bt2 horizon Management Hue: 5YR, 7.5YR, or 10YR Value: 4 to 6 dry; 4 or 5 moist For management information about this map unit, Chroma: 4, 6, or 8 see appropriate sections in Part II of this publication. Texture: Clay loam or clay Clay content: 35 to 60 percent Content of rock fragments: 35 to 70 percent—5 to 45E—Redchief cobbly loam, 20 percent stones and cobbles; 30 to 15 to 35 percent slopes 50 percent pebbles Reaction: pH 5.1 to 7.3 Setting Bt3 horizon Hue: 5YR, 7.5YR, or 10YR Landform: Mountains Value: 4 to 6 dry; 4 or 5 moist Slope: 15 to 35 percent Chroma: 3, 4, 6, or 8 Elevation: 5,000 to 8,600 feet Clay content: 40 to 60 percent Mean annual precipitation: 19 to 22 inches Content of rock fragments: 35 to 70 percent—5 to Frost-free period: 30 to 70 days 20 percent cobbles; 30 to 60 percent pebbles Composition Reaction: pH 5.1 to 7.3 Major Components Redchief and similar soils: 85 percent 45D—Redchief cobbly loam, 4 to 15 percent slopes Minor Components Soils that are moderately deep to deep: 0 to 10 percent Setting Areas of rock outcrop: 0 to 5 percent Landform: Mountains Major Component Description Slope: 4 to 15 percent Elevation: 5,000 to 8,600 feet Surface layer texture: Cobbly loam Mean annual precipitation: 19 to 22 inches Depth class: Very deep (more than 60 inches) Frost-free period: 30 to 70 days Drainage class: Well drained Dominant parent material: Igneous colluvium Composition Native plant cover type: Rangeland Major Components Flooding: None Redchief and similar soils: 85 percent Available water capacity: Mainly 5.4 inches Powell County Area, Montana—Part I 161
A typical soil description with range in A typical soil description with range in characteristics is included, in alphabetical order, in characteristics is included, in alphabetical order, in this section. this section. Management Management For management information about this map unit, For management information about this map unit, see appropriate sections in Part II of this publication. see appropriate sections in Part II of this publication.
845D—Redchief-Copenhaver gravelly 845E—Redchief-Copenhaver gravelly loams, 8 to 15 percent slopes loams, 15 to 35 percent slopes
Setting Setting Landform: Landform: • Redchief—Hills • Redchief—Hills • Copenhaver—Hills • Copenhaver—Hills Slope: Slope: • Redchief—8 to 15 percent • Redchief—15 to 35 percent • Copenhaver—8 to 15 percent • Copenhaver—15 to 35 percent Elevation: 5,000 to 8,600 feet Elevation: 5,000 to 8,600 feet Mean annual precipitation: 18 to 22 inches Mean annual precipitation: 18 to 22 inches Frost-free period: 30 to 70 days Frost-free period: 30 to 70 days Composition Composition Major Components Major Components Redchief and similar soils: 65 percent Redchief and similar soils: 65 percent Copenhaver and similar soils: 20 percent Copenhaver and similar soils: 20 percent Minor Components Minor Components Areas of rock outcrop: 0 to 8 percent Areas of rock outcrop: 0 to 8 percent Soils that have slopes more than 15 percent: 0 to Soils that have slopes more than 35 percent: 0 to 7 percent 7 percent Major Component Description Major Component Description Redchief Redchief Surface layer texture: Gravelly loam Surface layer texture: Gravelly loam Depth class: Very deep (more than 60 inches) Depth class: Very deep (more than 60 inches) Drainage class: Well drained Drainage class: Well drained Dominant parent material: Igneous colluvium Dominant parent material: Igneous colluvium Native plant cover type: Rangeland Native plant cover type: Rangeland Flooding: None Flooding: None Available water capacity: Mainly 5.4 inches Available water capacity: Mainly 5.4 inches
Copenhaver Copenhaver Surface layer texture: Gravelly loam Surface layer texture: Gravelly loam Depth class: Shallow (10 to 20 inches) Depth class: Shallow (10 to 20 inches) Drainage class: Well drained Drainage class: Well drained Dominant parent material: Material weathered from Dominant parent material: Material weathered from igneous rocks igneous rocks Native plant cover type: Rangeland Native plant cover type: Rangeland Flooding: None Flooding: None Available water capacity: Mainly 1.4 inches Available water capacity: Mainly 1.4 inches 162 Soil Survey
A typical soil description with range in discontinuous tubular pores; common distinct characteristics is included, in alphabetical order, in clay films on faces of peds; 10 percent cobbles this section. and 30 percent pebbles; slightly acid; clear smooth boundary. Management Bt—6 to 15 inches; reddish brown (5YR 4/4) very For management information about this map unit, gravelly clay loam, dark reddish gray (5YR 4/2) see appropriate sections in Part II of this publication. moist; moderate fine subangular blocky structure; very hard, very firm, slightly sticky, moderately plastic; many medium and common very fine, Relyea Series fine, and coarse roots; many very fine and fine discontinuous irregular and many very fine Depth class: Very deep discontinuous tubular pores; many distinct clay Drainage class: Well drained films on faces of peds; 10 percent cobbles and Permeability: Moderately slow 30 percent pebbles; neutral; clear wavy boundary. Landform: Mountains Btk—15 to 28 inches; brown (7.5YR 5/4) very gravelly Parent material: Colluvium derived from limestone clay loam, dark brown (7.5YR 4/4) moist; and calcareous argillite moderate medium subangular blocky structure; Slope range: 15 to 60 percent slightly hard, firm, slightly sticky, moderately Elevation range: 4,600 to 7,500 feet plastic; common very fine, fine, and medium and Annual precipitation: 20 to 30 inches few coarse roots; many very fine and fine Annual air temperature: 35 to 38 degrees F discontinuous irregular pores; few faint clay Frost-free period: 30 to 70 days films on faces of peds; 15 percent cobbles and 35 percent pebbles; disseminated lime; Taxonomic Class: Clayey-skeletal, mixed, continuous faint and distinct lime casts on superactive Eutric Glossocryalfs underside of coarse fragments; strongly effervescent; moderately alkaline; gradual wavy Typical Pedon boundary. Bk1—28 to 36 inches; pinkish gray (7.5YR 7/2) Relyea gravelly loam, in an area of Relyea-Helmville extremely gravelly loam, light brown (7.5YR 6/4) complex, 35 to 60 percent slopes, in an area of moist; weak medium subangular blocky structure woodland, 1,900 feet south and 2,700 feet east of parting to weak medium granular structure; the northwest corner of sec. 2, T. 10 N., R. 9 W. slightly hard, friable, slightly sticky, slightly plastic; Oi—2 inches to 0; undecomposed and slightly few very fine, fine, and medium and few very fine decomposed forest litter. discontinuous irregular pores; 20 percent cobbles E—0 to 3 inches; light reddish brown (5YR 6/3) and 45 percent pebbles; disseminated lime; gravelly loam, reddish brown (5YR 4/3) moist; continuous faint and distinct lime casts weak fine subangular blocky structure parting to surrounding coarse fragments; violently weak fine granular structure; slightly hard, very effervescent; moderately alkaline; gradual wavy friable, slightly sticky, slightly plastic; many very boundary. fine and fine and common medium and coarse Bk2—36 to 60 inches; pinkish gray (7.5YR 7/2) roots; many very fine and fine discontinuous extremely cobbly loam, light brown (7.5YR 6/4) irregular and few very fine discontinuous tubular moist; weak fine subangular blocky structure; pores; 5 percent cobbles and 25 percent pebbles; slightly hard, friable, slightly sticky, slightly plastic; slightly acid; clear smooth boundary. few very fine roots; few very fine discontinuous Bt/E—3 to 6 inches; 80 percent is reddish brown irregular pores; 30 percent cobbles and (5YR 4/4) very gravelly clay loam, dark reddish 40 percent pebbles; disseminated lime; gray (5YR 4/2) moist (B part); 20 percent is light continuous faint and distinct lime casts reddish brown (5YR 6/3) very gravelly loam, surrounding coarse fragments; violently reddish brown (5YR 4/3) moist tongues (E part); effervescent; moderately alkaline. texture mixed is very gravelly clay loam; Range in Characteristics moderate fine and medium subangular blocky structure; hard, firm, slightly sticky, moderately Soil temperature: 37 to 40 degrees F plastic; many very fine and fine and common Moisture control section: Between depths of 4 and medium and coarse roots; many very fine and 12 inches fine discontinuous irregular and many very fine Depth to the Bk horizon: 13 to 35 inches Powell County Area, Montana—Part I 163
E horizon Bk2 horizon Hue: 5YR, 7.5YR, or 10YR Hue: 7.5YR or 10YR Value: 6 or 7 dry; 3 to 5 moist Value: 6 or 7 dry; 5 or 6 moist Chroma: 2 or 3 Chroma: 2 to 4 or 6 Clay content: 20 to 27 percent Texture: Loam or clay loam Content of rock fragments: 15 to 35 percent—0 to Clay content: 18 to 30 percent 10 percent stones and cobbles; 15 to Content of rock fragments: 60 to 80 percent— 25 percent pebbles 20 to 35 percent stones and cobbles; 35 to Reaction: pH 6.1 to 7.3 45 percent pebbles Calcium carbonate equivalent: 15 to 35 percent Bt/E horizon Reaction: pH 7.9 to 8.4 Hue: 5YR, 7.5YR, or 10YR Value: B part—4 or 5 dry, 3 or 4 moist; E part— 5 or 6 dry, 4 or 5 moist 185E—Relyea-Helmville complex, Chroma: B part—2 to 4 or 6; E part—2 or 3 15 to 35 percent slopes Texture, mixed: Clay loam or silty clay loam Clay content, mixed: 27 to 35 percent Setting Content of rock fragments: 15 to 45 percent—5 to 15 percent stones and cobbles; 10 to Landform: 30 percent pebbles • Relyea—Mountains Reaction: pH 6.1 to 7.3 • Helmville—Mountains Slope: Bt horizon • Relyea—15 to 35 percent Hue: 5YR, 7.5YR, or 10YR • Helmville—15 to 35 percent Value: 4 or 5 dry; 3 or 4 moist Elevation: 4,600 to 7,000 feet Chroma: 2 to 4 or 6 Mean annual precipitation: 20 to 30 inches Texture: Clay loam, clay, or silty clay loam Frost-free period: 30 to 70 days Clay content: 35 to 50 percent Content of rock fragments: 35 to 60 percent—5 to Composition 20 percent stones and cobbles; 30 to Major Components 40 percent pebbles Relyea and similar soils: 55 percent Reaction: pH 6.1 to 7.3 Helmville and similar soils: 30 percent Btk horizon Minor Components Hue: 7.5YR or 10YR Danaher soils: 0 to 10 percent Value: 5 to 7 dry; 4 to 6 moist Areas of rock outcrop: 0 to 5 percent Chroma: 2 to 4 or 6 Texture: Clay loam, clay, or silty clay loam Major Component Description Clay content: 27 to 45 percent Relyea Content of rock fragments: 35 to 60 percent— Surface layer texture: Gravelly loam 10 to 20 percent stones and cobbles; 25 to Depth class: Very deep (more than 60 inches) 40 percent pebbles Drainage class: Well drained Calcium carbonate equivalent: 15 to 30 percent Dominant parent material: Colluvium Reaction: pH 7.9 to 8.4 Native plant cover type: Forestland Bk1 horizon Flooding: None Hue: 7.5YR or 10YR Available water capacity: Mainly 4.7 inches Value: 6 or 7 dry; 5 or 6 moist Chroma: 2 to 4 or 6 Helmville Texture: Loam or clay loam Surface layer texture: Cobbly loam Clay content: 18 to 30 percent Depth class: Very deep (more than 60 inches) Content of rock fragments: 40 to 75 percent— Drainage class: Well drained 15 to 30 percent stones and cobbles; 25 to Dominant parent material: Colluvium 45 percent pebbles Native plant cover type: Forestland Calcium carbonate equivalent: 15 to 35 percent Flooding: None Reaction: pH 7.9 to 8.4 Available water capacity: Mainly 5.5 inches 164 Soil Survey
A typical soil description with range in Management characteristics is included, in alphabetical order, in this section. For management information about this map unit, see appropriate sections in Part II of this publication. Management For management information about this map unit, see appropriate sections in Part II of this publication. 485E—Relyea-Helmville complex, moist, 15 to 35 percent slopes 185F—Relyea-Helmville complex, 35 to 60 percent slopes Setting Landform: Setting • Relyea—Mountains Landform: • Helmville—Mountains • Relyea—Mountains Slope: • Helmville—Mountains • Relyea—15 to 35 percent Slope: • Helmville—15 to 35 percent • Relyea—35 to 60 percent Elevation: 4,600 to 7,500 feet • Helmville—35 to 60 percent Mean annual precipitation: 20 to 30 inches Elevation: 4,600 to 7,000 feet Frost-free period: 30 to 70 days Mean annual precipitation: 20 to 30 inches Composition Frost-free period: 30 to 70 days Major Components Composition Relyea and similar soils: 55 percent Major Components Helmville and similar soils: 30 percent Relyea and similar soils: 55 percent Minor Components Helmville and similar soils: 30 percent Danaher soils: 0 to 8 percent Minor Components Soils that have slopes more than 35 percent: 0 to Danaher soils: 0 to 10 percent 7 percent Areas of rock outcrop: 0 to 5 percent Major Component Description Major Component Description Relyea Relyea Surface layer texture: Gravelly loam Surface layer texture: Gravelly loam Depth class: Very deep (more than 60 inches) Depth class: Very deep (more than 60 inches) Drainage class: Well drained Drainage class: Well drained Dominant parent material: Colluvium Dominant parent material: Colluvium Native plant cover type: Forestland Native plant cover type: Forestland Flooding: None Flooding: None Available water capacity: Mainly 4.7 inches Available water capacity: Mainly 4.7 inches
Helmville Helmville Surface layer texture: Cobbly loam Surface layer texture: Cobbly loam Depth class: Very deep (more than 60 inches) Depth class: Very deep (more than 60 inches) Drainage class: Well drained Drainage class: Well drained Dominant parent material: Colluvium Dominant parent material: Colluvium Native plant cover type: Forestland Native plant cover type: Forestland Flooding: None Flooding: None Available water capacity: Mainly 5.5 inches Available water capacity: Mainly 5.5 inches
A typical soil description with range in A typical soil description with range in characteristics is included, in alphabetical order, in characteristics is included, in alphabetical order, in this section. this section. Powell County Area, Montana—Part I 165
Management Management For management information about this map unit, For management information about this map unit, see appropriate sections in Part II of this publication. see appropriate sections in Part II of this publication.
485F—Relyea-Helmville complex, moist, Rittel Series 35 to 60 percent slopes Depth class: Moderately deep Drainage class: Well drained Setting Permeability: Slow Landform: Landform: Mountains • Relyea—Mountains Parent material: Material derived from • Helmville—Mountains semiconsolidated shale Slope: Slope range: 15 to 35 percent • Relyea—35 to 60 percent Elevation range: 4,400 to 6,500 feet • Helmville—35 to 60 percent Annual precipitation: 18 to 25 inches Elevation: 4,600 to 7,500 feet Annual air temperature: 38 to 42 degrees F Mean annual precipitation: 20 to 30 inches Frost-free period: 70 to 90 days Frost-free period: 30 to 70 days Taxonomic Class: Fine, mixed, superactive, frigid Composition Typic Haplustalfs Major Components Typical Pedon Relyea and similar soils: 55 percent Helmville and similar soils: 30 percent Rittel loam, 15 to 35 percent slopes, in an area of woodland, 2,150 feet north and 2,400 feet east of the Minor Components southwest corner of sec. 23, T. 11 N., R. 11 W. Danaher soils: 0 to 8 percent Soils that have slopes more than 60 percent: 0 to E1—0 to 6 inches; light brownish gray (2.5Y 6/2) 7 percent loam, dark grayish brown (2.5Y 4/2) moist; moderate fine granular structure; soft, very Major Component Description friable, slightly sticky, slightly plastic; many fine, Relyea medium, and coarse roots; many very fine Surface layer texture: Gravelly loam discontinuous irregular pores; slightly acid; clear Depth class: Very deep (more than 60 inches) smooth boundary. Drainage class: Well drained E2—6 to 13 inches; light brownish gray (2.5Y 7/2) Dominant parent material: Colluvium loam, dark grayish brown (2.5Y 5/3) moist; weak Native plant cover type: Forestland fine granular structure; soft, very friable, slightly Flooding: None sticky, slightly plastic; many fine, medium, and Available water capacity: Mainly 4.7 inches coarse roots; many very fine discontinuous irregular pores; neutral; clear smooth boundary. Helmville E/Bt—13 to 19 inches; 70 percent is light brownish Surface layer texture: Cobbly loam gray (2.5Y 7/2) clay loam, very dark grayish Depth class: Very deep (more than 60 inches) brown (2.5Y 5/3) moist (E part); 30 percent is Drainage class: Well drained brown (7.5YR 5/4) clay loam, dark brown (7.5YR Dominant parent material: Colluvium 4/4) moist (B part); moderate medium subangular Native plant cover type: Forestland blocky structure; slightly hard, friable, moderately Flooding: None sticky and moderately plastic; many fine, medium, Available water capacity: Mainly 5.5 inches and coarse roots; common medium tubular pores; neutral; clear wavy boundary. A typical soil description with range in Bt—19 to 27 inches; brown (7.5YR 5/4) clay loam, characteristics is included, in alphabetical order, in dark brown (7.5YR 4/4) moist; moderate medium this section. subangular blocky structure; hard, friable, 166 Soil Survey
moderately sticky and moderately plastic; Composition common fine and medium roots; common Major Components medium tubular pores; common faint clay films on Rittel and similar soils: 85 percent faces of peds; neutral; clear wavy boundary. Cr—27 to 60 inches; light brownish gray (2.5Y 6/2) Minor Components fractured shale, dark grayish brown (2.5Y 4/2) Very gravelly clayey soils: 0 to 5 percent moist. Soils that are shallow to shale: 0 to 5 percent Soils that have slopes more than 35 percent: 0 to Range in Characteristics 5 percent Soil temperature: 42 to 47 degrees F Major Component Description Moisture control section: Between depths of 4 and 12 inches Surface layer texture: Loam Depth to the Cr horizon: 20 to 40 inches Depth class: Moderately deep (20 to 40 inches) Other features: The Rittel soil is a taxadjunct to the Drainage class: Well drained series. It classifies as fine-loamy, mixed, Dominant parent material: Semiconsolidated shale superactive, frigid Typic Haplustalfs. It does not residuum meet the clay requirements of the fine family but Native plant cover type: Forestland has similar use and management. Flooding: None Available water capacity: Mainly 4.6 inches E horizons Value: 6 or 7 dry; 4 or 5 moist A typical soil description with range in Chroma: 2 or 3 characteristics is included, in alphabetical order, in Clay content: 15 to 27 percent this section. Content of rock fragments: 0 to 20 percent—0 to 10 percent cobbles; 0 to 10 percent angular Management pebbles For management information about this map unit, Reaction: pH 5.6 to 7.3 see appropriate sections in Part II of this publication. E/Bt horizon Hue: 10YR, 7.5YR, or 2.5YR Value: E part—6 or 7 dry, 4 or 5 moist; B part— Rochester Series 5 or 6 dry, 4 or 5 moist Depth class: Very deep Chroma: 2 to 4 Drainage class: Excessively drained Texture: Clay loam, clay, or silty clay Permeability: Rapid Clay content: 35 to 50 percent Landform: Mountains Content of rock fragments: 0 to 20 percent Parent material: Granitic colluvium pebbles Slope range: 4 to 60 percent Reaction: pH 5.6 to 7.3 Elevation range: 4,500 to 5,500 feet Bt horizon Annual precipitation: 18 to 25 inches Hue: 10YR, 7.5YR, or 2.5Y Annual air temperature: 38 to 42 degrees F Value: 5 or 6 dry; 4 or 5 moist Frost-free period: 70 to 90 days Chroma: 2 to 4 Texture: Clay loam, clay, or silty clay Taxonomic Class: Sandy-skeletal, mixed, frigid Typic Clay content: 35 to 50 percent Ustorthents Reaction: pH 5.6 to 7.3 Typical Pedon Rochester very stony sandy loam, in an area of 91E—Rittel loam, 15 to 35 percent slopes Ambrant-Rochester complex, cool, 15 to 35 percent slopes, in an area of woodland, 400 feet south and Setting 1,200 feet east of the northwest corner of sec. 5, T. 13 N., R. 12 W. Landform: Mountains Slope: 15 to 35 percent Oe—2 inches to 0; partially decomposed organic Elevation: 4,400 to 6,500 feet matter. Mean annual precipitation: 18 to 25 inches A—0 to 3 inches; grayish brown (10YR 5/2) very Frost-free period: 70 to 90 days stony sandy loam, very dark grayish brown Powell County Area, Montana—Part I 167
(10YR 3/2) moist; weak very fine and fine Chroma: 1 to 3 granular structure; soft, very friable, nonsticky, Texture: Loamy sand, loamy coarse sand, sand, nonplastic; common very fine, fine, and medium or coarse sand (50 percent or more of the roots; few very fine discontinuous interstitial sand fraction is medium sand and coarser) pores; 25 percent stones, 5 percent cobbles, and Clay content: 0 to 10 percent 15 percent pebbles; neutral; clear smooth Content of rock fragments: 35 to 80 percent—0 to boundary. 40 percent boulders, stones, and cobbles; C1—3 to 16 inches; pale brown (10YR 6/3) very 20 to 60 percent pebbles stony loamy sand, brown (10YR 4/3) moist; weak Reaction: pH 6.1 to 7.8 fine and medium subangular blocky structure; soft, very friable, nonsticky, nonplastic; common medium and few very fine and fine roots; few very Roy Series fine discontinuous interstitial pores; 40 percent Depth class: Very deep stones and 10 percent cobbles; slightly acid; Drainage class: Well drained gradual smooth boundary. Permeability: Moderately slow C2—16 to 60 inches; pale brown (10YR 6/3) very Landform: Mountains, hills, alluvial fans, and stream stony loamy sand, brown (10YR 4/3) moist; terraces single grain; loose, nonsticky, nonplastic; few Parent material: Alluvium and colluvium derived from fine and medium roots; few very fine volcanic rock discontinuous interstitial pores; 40 percent Slope range: 0 to 60 percent stones and 15 percent cobbles; slightly acid. Elevation range: 3,800 to 5,600 feet Annual precipitation: 15 to 19 inches Range in Characteristics Annual air temperature: 39 to 44 degrees F Soil temperature: 40 to 47 degrees F Frost-free period: 70 to 90 days Moisture control section: Between depths of 12 and 35 inches Taxonomic Class: Clayey-skeletal, mixed, superactive, frigid Typic Argiustolls A horizon Hue: 10YR or 2.5Y Typical Pedon Value: 4 to 6 dry; 3 to 5 moist Roy gravelly loam, 8 to 15 percent slopes, in an area Chroma: 1 to 3 of rangeland, 1,900 feet north and 2,600 feet east of Clay content: 0 to 10 percent the southwest corner of sec. 6, T. 13 N., R. 10 W. Content of rock fragments: 35 to 60 percent— 20 to 30 percent boulders, stones, and A—0 to 8 inches; dark grayish brown (10YR 4/2) cobbles; 15 to 30 percent pebbles gravelly loam, very dark grayish brown (10YR Rock fragments, surface cover: 0 to 3.0 percent 3/2) moist; moderate medium and fine granular stones or boulders structure; slightly hard, friable, slightly sticky, Reaction: pH 6.6 to 7.3 slightly plastic; many very fine and common fine and medium roots; common very fine and few C1 horizon fine discontinuous irregular pores; 5 percent Hue: 10YR or 2.5Y cobbles and 25 percent pebbles; neutral; clear Value: 6 or 7 dry; 4 to 6 moist smooth boundary. Chroma: 1 to 3 Bt1—8 to 12 inches; brown (10YR 5/3) very gravelly Texture: Loamy sand, loamy coarse sand, sandy clay, very dark grayish brown (10YR 3/2) moist; loam, coarse sandy loam, or coarse sand moderate very fine subangular blocky structure; (50 percent or more of the sand fraction is slightly hard, friable, moderately sticky and medium sand and coarser) moderately plastic; common very fine and fine Clay content: 0 to 10 percent roots; common very fine and few fine Content of rock fragments: 15 to 80 percent—5 to discontinuous irregular pores; few faint clay 50 percent boulders, stones, and cobbles; films on faces of peds; 15 percent cobbles and 10 to 30 percent pebbles 40 percent pebbles; neutral; clear smooth Reaction: pH 5.6 to 7.3 boundary. C2 horizon Bt2—12 to 24 inches; strong brown (7.5YR 5/6) very Hue: 10YR or 2.5Y gravelly clay, strong brown (7.5YR 4/6) moist; Value: 6 or 7 dry; 4 to 6 moist strong medium angular blocky structure; hard, 168 Soil Survey
firm, moderately sticky and moderately plastic; Content of rock fragments: 40 to 60 percent—5 to common fine and medium roots; few very fine 10 percent cobbles; 35 to 50 percent pebbles discontinuous irregular pores; many distinct clay Reaction: pH 6.6 to 7.8 films on faces of peds; 10 percent cobbles and Btk and Bk horizons 50 percent pebbles; neutral; gradual wavy Hue: 7.5YR, 5YR, or 2.5Y boundary. Value: 5 or 6 dry; 4 or 5 moist Btk—24 to 31 inches; reddish yellow (7.5YR 6/6) very Chroma: 3, 4, or 6 gravelly clay loam, strong brown (7.5YR 5/6) Texture: Clay loam or sandy clay loam moist; moderate medium subangular blocky Clay content: 27 to 40 percent structure; hard, firm, moderately sticky and Content of rock fragments: 40 to 65 percent— moderately plastic; common fine roots; few very 10 to 20 percent cobbles; 30 to 45 percent fine discontinuous irregular pores; common pebbles distinct clay films on faces of peds; 15 percent Calcium carbonate equivalent: 2 to 15 percent cobbles and 45 percent pebbles; disseminated Reaction: pH 7.4 to 8.4 lime; strongly effervescent; moderately alkaline; gradual wavy boundary. Bk—31 to 60 inches; light yellowish brown (10YR 6/4) extremely gravelly clay loam, yellowish brown 46B—Roy gravelly loam, (10YR 5/6) moist; moderate medium subangular 0 to 4 percent slopes blocky structure; hard, firm, moderately sticky and moderately plastic; few very fine roots; few very Setting fine discontinuous irregular pores; 20 percent cobbles and 45 percent pebbles; disseminated Landform: Alluvial fans and stream terraces lime; violently effervescent; moderately alkaline. Slope: 0 to 4 percent Elevation: 3,800 to 5,600 feet Range in Characteristics Mean annual precipitation: 15 to 19 inches Soil temperature: 40 to 47 degrees F Frost-free period: 70 to 90 days Thickness of the mollic epipedon: 10 to 16 inches Composition Depth to the Bk horizon: 20 to 40 inches Major Components A horizon Roy and similar soils: 85 percent Hue: 7.5YR or 10YR Value: 4 or 5 dry; 2 or 3 moist Minor Components Chroma: 2 or 3 Soils that have slopes more than 4 percent: 0 to Clay content: 18 to 27 percent 4 percent Content of rock fragments: 15 to 35 percent—0 to Roy cobbly loam: 0 to 4 percent 10 percent stones and cobbles; 15 to 25 Soils that are loamy throughout: 0 to 4 percent percent pebbles Somewhat poorly drained soils: 0 to 3 percent Reaction: pH 6.1 to 7.8 Major Component Description Bt1 horizon Surface layer texture: Gravelly loam Hue: 7.5YR or 10YR Depth class: Very deep (more than 60 inches) Value: 4 or 5 dry; 3 or 4 moist Drainage class: Well drained Chroma: 2 to 4 Dominant parent material: Alluvium Texture: Clay loam or clay Native plant cover type: Rangeland Clay content: 35 to 50 percent Flooding: None Content of rock fragments: 40 to 60 percent—5 to Available water capacity: Mainly 4.7 inches 10 percent cobbles; 35 to 50 percent pebbles Reaction: pH 6.6 to 7.8 A typical soil description with range in Bt2 horizon characteristics is included, in alphabetical order, in Hue: 7.5YR or 10YR this section. Value: 4 or 5 dry; 3 or 4 moist Management Chroma: 2 to 4 or 6 Texture: Clay loam or clay For management information about this map unit, Clay content: 35 to 50 percent see appropriate sections in Part II of this publication. Powell County Area, Montana—Part I 169
46C—Roy gravelly loam, Minor Components 4 to 8 percent slopes Soils that have slopes more than 15 percent: 0 to 4 percent Roy cobbly loam: 0 to 4 percent Setting Soils that are loamy throughout: 0 to 4 percent Landform: Alluvial fans Soils that are calcareous throughout: 0 to 3 percent Slope: 4 to 8 percent Major Component Description Elevation: 3,800 to 5,600 feet Mean annual precipitation: 15 to 19 inches Surface layer texture: Gravelly loam Frost-free period: 70 to 90 days Depth class: Very deep (more than 60 inches) Drainage class: Well drained Composition Dominant parent material: Alluvium Major Components Native plant cover type: Rangeland Roy and similar soils: 85 percent Flooding: None Available water capacity: Mainly 4.7 inches Minor Components Soils that have slopes more than 4 percent: 0 to A typical soil description with range in 4 percent characteristics is included, in alphabetical order, in Roy cobbly loam: 0 to 4 percent this section. Soils that are loamy throughout: 0 to 4 percent Somewhat poorly drained soils: 0 to 3 percent Management Major Component Description For management information about this map unit, see appropriate sections in Part II of this publication. Surface layer texture: Gravelly loam Depth class: Very deep (more than 60 inches) Drainage class: Well drained Dominant parent material: Alluvium 146D—Roy cobbly loam, Native plant cover type: Rangeland 8 to 15 percent slopes Flooding: None Available water capacity: Mainly 4.7 inches Setting A typical soil description with range in Landform: Alluvial fans characteristics is included, in alphabetical order, in Slope: 8 to 15 percent this section. Elevation: 3,800 to 5,600 feet Mean annual precipitation: 15 to 19 inches Management Frost-free period: 70 to 90 days For management information about this map unit, Composition see appropriate sections in Part II of this publication. Major Components Roy and similar soils: 85 percent 46D—Roy gravelly loam, 8 to 15 percent slopes Minor Components Winspect soils: 0 to 5 percent Danvers soils: 0 to 5 percent Setting Shawmut soils: 0 to 5 percent Landform: Alluvial fans Major Component Description Slope: 8 to 15 percent Elevation: 3,800 to 5,600 feet Surface layer texture: Cobbly loam Mean annual precipitation: 15 to 19 inches Depth class: Very deep (more than 60 inches) Frost-free period: 70 to 90 days Drainage class: Well drained Dominant parent material: Alluvium Composition Native plant cover type: Rangeland Major Components Flooding: None Roy and similar soils: 85 percent Available water capacity: Mainly 4.6 inches 170 Soil Survey
A typical soil description with range in Slope: characteristics is included, in alphabetical order, in • Roy—15 to 35 percent this section. • Shawmut—15 to 35 percent • Danvers—15 to 35 percent Management Elevation: 3,800 to 5,600 feet For management information about this map unit, Mean annual precipitation: 15 to 19 inches see appropriate sections in Part II of this publication. Frost-free period: 70 to 90 days Composition 146E—Roy cobbly loam, Major Components 15 to 35 percent slopes Roy and similar soils: 35 percent Shawmut and similar soils: 25 percent Setting Danvers and similar soils: 25 percent Landform: Hills Minor Components Slope: 15 to 35 percent Soils that have slopes more than 35 percent: 0 to Elevation: 3,800 to 5,600 feet 5 percent Mean annual precipitation: 15 to 19 inches Soils that are calcareous throughout: 0 to 5 percent Frost-free period: 70 to 90 days Roy extremely cobbly loam: 0 to 5 percent Composition Major Component Description Major Components Roy Roy and similar soils: 85 percent Surface layer texture: Cobbly loam Depth class: Very deep (more than 60 inches) Minor Components Drainage class: Well drained Winspect soils: 0 to 5 percent Dominant parent material: Alluvium Danvers soils: 0 to 5 percent Native plant cover type: Rangeland Shawmut soils: 0 to 5 percent Flooding: None Major Component Description Available water capacity: Mainly 4.6 inches Surface layer texture: Cobbly loam Shawmut Depth class: Very deep (more than 60 inches) Surface layer texture: Cobbly loam Drainage class: Well drained Depth class: Very deep (more than 60 inches) Dominant parent material: Alluvium Drainage class: Well drained Native plant cover type: Rangeland Dominant parent material: Alluvium Flooding: None Native plant cover type: Rangeland Available water capacity: Mainly 4.6 inches Flooding: None Available water capacity: Mainly 5.1 inches A typical soil description with range in characteristics is included, in alphabetical order, in Danvers this section. Surface layer texture: Cobbly clay loam Management Depth class: Very deep (more than 60 inches) Drainage class: Well drained For management information about this map unit, Dominant parent material: Alluvium see appropriate sections in Part II of this publication. Native plant cover type: Rangeland Flooding: None 351E—Roy-Shawmut-Danvers complex, Available water capacity: Mainly 9.1 inches 15 to 35 percent slopes A typical soil description with range in characteristics is included, in alphabetical order, in Setting this section. Landform: Management • Roy—Alluvial fans • Shawmut—Alluvial fans For management information about this map unit, • Danvers—Alluvial fans see appropriate sections in Part II of this publication. Powell County Area, Montana—Part I 171
351F—Roy-Shawmut-Danvers complex, Flooding: None 35 to 60 percent slopes Available water capacity: Mainly 9.1 inches A typical soil description with range in Setting characteristics is included, in alphabetical order, in Landform: this section. • Roy—Alluvial fans Management • Shawmut—Alluvial fans • Danvers—Alluvial fans For management information about this map unit, Slope: see appropriate sections in Part II of this publication. • Roy—35 to 60 percent • Shawmut—35 to 60 percent • Danvers—35 to 60 percent 846D—Roy-Tolbert complex, Elevation: 3,800 to 5,600 feet 8 to 15 percent slopes Mean annual precipitation: 15 to 19 inches Frost-free period: 70 to 90 days Setting Composition Landform: Major Components • Roy—Mountains Roy and similar soils: 35 percent • Tolbert—Mountains Shawmut and similar soils: 25 percent Slope: Danvers and similar soils: 25 percent • Roy—8 to 15 percent • Tolbert—8 to 15 percent Minor Components Elevation: 3,800 to 5,600 feet Soils that have slopes more than 60 percent: 0 to Mean annual precipitation: 15 to 19 inches 5 percent Frost-free period: 70 to 90 days Soils that are calcareous throughout: 0 to 5 percent Roy extremely cobbly loam: 0 to 5 percent Composition Major Components Major Component Description Roy and similar soils: 65 percent Tolbert and similar soils: 20 percent Roy Surface layer texture: Cobbly loam Minor Components Depth class: Very deep (more than 60 inches) Areas of rock outcrop: 0 to 8 percent Drainage class: Well drained Danvers soils: 0 to 4 percent Dominant parent material: Alluvium Martinsdale soils: 0 to 3 percent Native plant cover type: Rangeland Major Component Description Flooding: None Available water capacity: Mainly 4.6 inches Roy Surface layer texture: Gravelly loam Shawmut Depth class: Very deep (more than 60 inches) Surface layer texture: Cobbly loam Drainage class: Well drained Depth class: Very deep (more than 60 inches) Dominant parent material: Colluvium Drainage class: Well drained Native plant cover type: Rangeland Dominant parent material: Alluvium Flooding: None Native plant cover type: Rangeland Available water capacity: Mainly 4.7 inches Flooding: None Available water capacity: Mainly 5.1 inches Tolbert Surface layer texture: Very stony loam Danvers Depth class: Shallow (10 to 20 inches) Surface layer texture: Cobbly clay loam Drainage class: Well drained Depth class: Very deep (more than 60 inches) Dominant parent material: Igneous residuum Drainage class: Well drained Native plant cover type: Rangeland Dominant parent material: Alluvium Flooding: None Native plant cover type: Rangeland Available water capacity: Mainly 1.7 inches 172 Soil Survey
A typical soil description with range in Management characteristics is included, in alphabetical order, in For management information about this map unit, this section. see appropriate sections in Part II of this publication. Management For management information about this map unit, 846F—Roy-Tolbert complex, see appropriate sections in Part II of this publication. 35 to 60 percent slopes
Setting 846E—Roy-Tolbert complex, 15 to 35 percent slopes Landform: • Roy—Mountains • Tolbert—Mountains Setting Slope: Landform: • Roy—35 to 60 percent • Roy—Mountains • Tolbert—35 to 60 percent • Tolbert—Mountains Elevation: 3,800 to 5,600 feet Slope: Mean annual precipitation: 15 to 19 inches • Roy—15 to 35 percent Frost-free period: 70 to 90 days • Tolbert—15 to 35 percent Composition Elevation: 3,800 to 5,600 feet Mean annual precipitation: 15 to 19 inches Major Components Frost-free period: 70 to 90 days Roy and similar soils: 65 percent Tolbert and similar soils: 20 percent Composition Minor Components Major Components Areas of rock outcrop: 0 to 8 percent Roy and similar soils: 65 percent Areas of rubble land: 0 to 7 percent Tolbert and similar soils: 20 percent Major Component Description Minor Components Areas of rock outcrop: 0 to 8 percent Roy Areas of rubble land: 0 to 7 percent Surface layer texture: Gravelly loam Depth class: Very deep (more than 60 inches) Major Component Description Drainage class: Well drained Roy Dominant parent material: Colluvium Surface layer texture: Gravelly loam Native plant cover type: Rangeland Depth class: Very deep (more than 60 inches) Flooding: None Drainage class: Well drained Available water capacity: Mainly 4.7 inches Dominant parent material: Colluvium Native plant cover type: Rangeland Tolbert Flooding: None Surface layer texture: Stony loam Available water capacity: Mainly 4.7 inches Depth class: Shallow (10 to 20 inches) Drainage class: Well drained Tolbert Dominant parent material: Igneous residuum Surface layer texture: Stony loam Native plant cover type: Rangeland Depth class: Shallow (10 to 20 inches) Flooding: None Drainage class: Well drained Available water capacity: Mainly 1.4 inches Dominant parent material: Igneous residuum Native plant cover type: Rangeland A typical soil description with range in Flooding: None characteristics is included, in alphabetical order, in Available water capacity: Mainly 1.4 inches this section. Management A typical soil description with range in characteristics is included, in alphabetical order, in For management information about this map unit, this section. see appropriate sections in Part II of this publication. Powell County Area, Montana—Part I 173
100—Rubble land-Rock outcrop complex moderate medium granular structure; soft, very friable, slightly sticky, slightly plastic; many very fine and fine and few medium roots; many very Setting fine and fine irregular pores; 20 percent pebbles; Landform: slightly acid; gradual wavy boundary. • Rubble land—Mountains E2—5 to 13 inches; light gray (10YR 7/2) gravelly • Rock outcrop—Mountains loam, grayish brown (10YR 5/2) moist; moderate Elevation: 3,900 to 7,600 feet medium granular structure; slightly hard, very Mean annual precipitation: 15 to 30 inches friable, slightly sticky, slightly plastic; many very Frost-free period: 30 to 90 days fine and fine roots; many very fine and fine irregular pores; 25 percent pebbles; neutral; Composition gradual wavy boundary. Major Components Bt/E—13 to 26 inches; 60 percent is grayish brown Rubble land: 55 percent (10YR 5/2) very gravelly clay loam, dark yellowish Rock outcrop: 30 percent brown (10YR 4/4) moist (B part); 40 percent is light brownish gray (10YR 6/2) very gravelly loam, Minor Components grayish brown (10YR 5/2) moist (E part); weak Areas of soils that support vegetation: 0 to 15 percent fine subangular blocky structure; slightly hard, Major Component Description friable, slightly sticky, slightly plastic; many very fine and fine roots; many very fine and fine Rubble land irregular pores; few faint clay films on faces of Definition: Areas having more than 90 percent peds; 10 percent cobbles and 40 percent boulders, stones, and cobbles on the surface, pebbles; neutral; gradual wavy boundary. supporting little or no vegetation Bt—26 to 60 inches; pale brown (10YR 6/3) very gravelly clay loam, brown (10YR 5/3) moist; weak Rock outcrop fine subangular blocky structure; hard, friable, Definition: Areas of exposed bedrock slightly sticky, slightly plastic; common very fine and fine roots; many very fine and fine irregular Rumblecreek Series pores; common faint clay films on faces of peds; 10 percent cobbles and 40 percent pebbles; Depth class: Very deep neutral. Drainage class: Well drained Permeability: Moderately slow Range in Characteristics Landform: Moraines, mountains, and hills Soil temperature: 40 to 46 degrees F Parent material: Alpine till and colluvium Moisture control section: Between depths of 4 and Slope range: 2 to 60 percent 12 inches Elevation range: 4,000 to 6,500 feet Depth to the argillic horizon: 10 to 22 inches Annual precipitation: 18 to 30 inches Annual air temperature: 38 to 42 degrees F E horizons Frost-free period: 70 to 90 days Hue: 10YR or 7.5YR Value: 6 or 7 dry; 4 to 6 moist Taxonomic Class: Loamy-skeletal, mixed, Chroma: 2 or 3 superactive, frigid Haplic Glossudalfs Clay content: 10 to 20 percent Content of rock fragments: 15 to 35 percent—0 to Typical Pedon 5 percent cobbles; 15 to 30 percent pebbles Rumblecreek gravelly loam, in an area of Winfall- Reaction: pH 5.1 to 7.3 Rumblecreek gravelly loams, 2 to 8 percent slopes, in Bt/E horizon an area of woodland, 2,800 feet south and 400 feet Hue: B part—10YR or 7.5YR; E part—10YR or west of the northeast corner of sec. 30, T. 15 N., 7.5YR R. 10 W. Value: B part—5 or 6 dry, 4 or 5 moist; E part— Oe—3 inches to 0; partially decomposed organic 6 or 7 dry, 5 or 6 moist matter. Chroma: B part—2, 3, 4, or 6; E part—2 or 3 E1—0 to 5 inches; light gray (10YR 7/2) gravelly Texture, mixed: Loam, clay loam, or sandy clay loam, dark grayish brown (10YR 4/2) moist; loam 174 Soil Survey
Clay content, mixed: 20 to 35 percent A typical soil description with range in Content of rock fragments: 35 to 60 percent—0 to characteristics is included, in alphabetical order, in 10 percent cobbles; 35 to 50 percent pebbles this section. Reaction: pH 5.6 to 6.5 Management Bt horizon For management information about this map unit, Hue: 10YR or 7.5YR see appropriate sections in Part II of this publication. Value: 5 or 6 dry; 4 or 5 moist Chroma: 3, 4, or 6 Texture: Clay loam or sandy clay loam Clay content: 20 to 35 percent 271E—Rumblecreek-Water complex, Content of rock fragments: 35 to 60 percent—0 to 8 to 25 percent slopes 10 percent cobbles; 35 to 50 percent pebbles Reaction: pH 5.6 to 6.5 Setting Landform: Moraines 271C—Rumblecreek-Water complex, Slope: 8 to 25 percent 2 to 8 percent slopes Elevation: 4,000 to 4,700 feet Mean annual precipitation: 20 to 30 inches Setting Frost-free period: 70 to 90 days Landform: Moraines Composition Slope: 2 to 8 percent Major Components Elevation: 4,000 to 4,700 feet Rumblecreek and similar soils: 75 percent Mean annual precipitation: 20 to 30 inches Water: 10 percent Frost-free period: 70 to 90 days Minor Components Composition Poorly drained soils: 0 to 5 percent Soils that have a thick volcanic ash surface: 0 to Major Components 5 percent Rumblecreek and similar soils: 75 percent Slopes more than 25 percent: 0 to 5 percent Water: 10 percent Major Component Description Minor Components Poorly drained soils: 0 to 5 percent Rumblecreek Soils that have a thick volcanic ash surface: 0 to Surface layer texture: Gravelly loam 5 percent Depth class: Very deep (more than 60 inches) Soils that have slopes more than 8 percent: 0 to Drainage class: Well drained 5 percent Dominant parent material: Alpine till Native plant cover type: Forestland Major Component Description Flooding: None Available water capacity: Mainly 5.2 inches Rumblecreek Surface layer texture: Gravelly loam Water Depth class: Very deep (more than 60 inches) Definition: Areas of open water Drainage class: Well drained Dominant parent material: Alpine till A typical soil description with range in Native plant cover type: Forestland characteristics is included, in alphabetical order, in Flooding: None this section. Available water capacity: Mainly 5.2 inches Management Water For management information about this map unit, Definition: Areas of open water see appropriate sections in Part II of this publication. Powell County Area, Montana—Part I 175
271F—Rumblecreek-Water complex, Composition 25 to 50 percent slopes Major Components Rumblecreek and similar soils: 85 percent Setting Minor Components Landform: Moraines Areas of rock outcrop: 0 to 5 percent Slope: 25 to 50 percent Bignell soils: 0 to 5 percent Elevation: 4,000 to 4,700 feet Crow soils: 0 to 3 percent Mean annual precipitation: 20 to 30 inches Trapps soils: 0 to 2 percent Frost-free period: 70 to 90 days Major Component Description Composition Surface layer texture: Gravelly loam Major Components Depth class: Very deep (more than 60 inches) Rumblecreek and similar soils: 75 percent Drainage class: Well drained Water: 10 percent Dominant parent material: Colluvium Minor Components Native plant cover type: Forestland Poorly drained soils: 0 to 5 percent Flooding: None Soils that have a thick volcanic ash surface: 0 to Available water capacity: Mainly 5.2 inches 5 percent Soils that have slopes more than 50 percent: 0 to A typical soil description with range in 5 percent characteristics is included, in alphabetical order, in this section. Major Component Description Management Rumblecreek Surface layer texture: Gravelly loam For management information about this map unit, Depth class: Very deep (more than 60 inches) see appropriate sections in Part II of this publication. Drainage class: Well drained Dominant parent material: Alpine till Native plant cover type: Forestland 395E—Rumblecreek gravelly loam, Flooding: None 15 to 35 percent slopes Available water capacity: Mainly 5.2 inches Setting Water Definition: Areas of open water Landform: Mountains Slope: 15 to 35 percent A typical soil description with range in Elevation: 4,000 to 6,500 feet characteristics is included, in alphabetical order, in Mean annual precipitation: 18 to 25 inches this section. Frost-free period: 70 to 90 days Management Composition For management information about this map unit, Major Components see appropriate sections in Part II of this publication. Rumblecreek and similar soils: 85 percent Minor Components 395D—Rumblecreek gravelly loam, Areas of rock outcrop: 0 to 3 percent 8 to 15 percent slopes Bignell soils: 0 to 3 percent Soils that have slopes more than 35 percent: 0 to 3 percent Setting Crow soils: 0 to 3 percent Landform: Mountains Trapps soils: 0 to 3 percent Slope: 8 to 15 percent Major Component Description Elevation: 4,000 to 6,500 feet Mean annual precipitation: 18 to 25 inches Surface layer texture: Gravelly loam Frost-free period: 70 to 90 days Depth class: Very deep (more than 60 inches) 176 Soil Survey
Drainage class: Well drained Saypo Series Dominant parent material: Colluvium Native plant cover type: Forestland Depth class: Very deep Flooding: None Drainage class: Somewhat poorly drained Available water capacity: Mainly 5.2 inches Permeability: Moderately slow Landform: Stream terraces and flood plains A typical soil description with range in Parent material: Alluvium characteristics is included, in alphabetical order, in Slope range: 0 to 4 percent this section. Elevation range: 3,800 to 5,000 feet Annual precipitation: 10 to 19 inches Management Annual air temperature: 39 to 44 degrees F For management information about this map unit, Frost-free period: 70 to 105 days see appropriate sections in Part II of this publication. Taxonomic Class: Fine-loamy, mixed, superactive, frigid Aquic Calciustolls 395F—Rumblecreek gravelly loam, Typical Pedon 35 to 60 percent slopes Saypo loam, 0 to 4 percent slopes, rarely flooded, in an area of pasture, 600 feet north and 1,850 feet Setting west of the southeast corner of sec. 4, T. 7 N., R. 9 W. Landform: Mountains Oe—2 inches to 0; partially decomposed organic Slope: 35 to 60 percent matter. Elevation: 4,000 to 6,500 feet Ap—0 to 7 inches; very dark gray (10YR 3/1) loam, Mean annual precipitation: 18 to 25 inches dark gray (10YR 4/1) dry; strong medium granular Frost-free period: 70 to 90 days structure; slightly hard, friable, nonsticky, slightly Composition plastic; many very fine and fine and common medium roots; many very fine irregular pores; Major Components slightly effervescent; slightly alkaline; clear Rumblecreek and similar soils: 85 percent smooth boundary. Minor Components Bk1—7 to 15 inches; dark grayish brown (10YR 4/2) Areas of rock outcrop: 0 to 3 percent silt loam, grayish brown (10YR 5/2) dry; strong Bignell soils: 0 to 3 percent medium granular structure; slightly hard, friable, Soils that have slopes more than 60 percent: 0 to nonsticky, slightly plastic; many very fine and fine 3 percent and common medium roots; many very fine Crow soils: 0 to 3 percent irregular pores; disseminated lime; few fine Trapps soils: 0 to 3 percent masses of lime; violently effervescent; moderately alkaline; gradual wavy boundary. Major Component Description Bk2—15 to 31 inches; dark grayish brown (10YR 4/2) Surface layer texture: Gravelly loam silt loam, light brownish gray (10YR 6/2) dry; Depth class: Very deep (more than 60 inches) moderate medium subangular blocky structure; Drainage class: Well drained slightly hard, friable, slightly sticky, slightly plastic; Dominant parent material: Colluvium common very fine and fine roots; many very fine Native plant cover type: Forestland irregular pores; disseminated lime; few fine Flooding: None masses of lime; violently effervescent; moderately Available water capacity: Mainly 5.2 inches alkaline; gradual wavy boundary. Bk3—31 to 47 inches; dark grayish brown (10YR 4/2) A typical soil description with range in silty clay loam, light brownish gray (10YR 6/2) characteristics is included, in alphabetical order, in dry; few fine distinct brown (10YR 4/3) redox this section. concentrations; weak fine subangular blocky structure; slightly hard, very friable, moderately Management sticky and moderately plastic; few very fine and For management information about this map unit, fine roots; many very fine irregular pores; see appropriate sections in Part II of this publication. disseminated lime; few fine masses of lime; Powell County Area, Montana—Part I 177
violently effervescent; moderately alkaline; clear Electrical conductivity: 0 to 2 mmhos/cm smooth boundary. Reaction: pH 7.9 to 8.4 C—47 to 60 inches; dark brown (7.5YR 4/4) loam, brown (7.5YR 5/4) dry; common fine distinct strong brown (7.5YR 4/6) redox concentrations; 435—Saypo loam, cool, 0 to 4 percent massive; soft, very friable, nonsticky, nonplastic; slopes, rarely flooded 5 percent pebbles; moderately alkaline.
Range in Characteristics Setting Soil temperature: 42 to 46 degrees F Landform: Flood plains Thickness of the mollic epipedon: 7 to 12 inches Slope: 0 to 4 percent Depth to the seasonal high water table: 24 to Elevation: 3,800 to 5,000 feet 42 inches Mean annual precipitation: 15 to 19 inches Depth to the Bk horizon: 5 to 12 inches Frost-free period: 70 to 90 days Ap horizon Composition Hue: 10YR or 2.5Y Major Components Value: 2 or 3 moist; 3 or 4 dry Saypo and similar soils: 85 percent Chroma: 1 or 2 Clay content: 22 to 27 percent Minor Components Content of rock fragments: 0 to 5 percent pebbles Poorly drained soils: 0 to 4 percent Calcium carbonate equivalent: 5 to 10 percent Kleinschmidt soils: 0 to 4 percent Reaction: 7.4 to 8.4 Gregson soils: 0 to 4 percent Very poorly drained soils: 0 to 3 percent Bk1 horizon Hue: 10YR or 2.5Y Major Component Description Value: 4 to 6 moist; 5 to 7 dry Surface layer texture: Loam Chroma: 2 or 3 Depth class: Very deep (more than 60 inches) Texture: Silt loam, clay loam, or loam Drainage class: Somewhat poorly drained Clay content: 22 to 35 percent Dominant parent material: Alluvium Content of rock fragments: 0 to 5 percent pebbles Native plant cover type: Rangeland Calcium carbonate equivalent: 20 to 25 percent Flooding: Rare Reaction: pH 7.9 to 8.4 Water table: Apparent Bk2 and Bk3 horizons Available water capacity: Mainly 7.9 inches Hue: 10YR or 2.5Y Value: 4 to 6 moist; 5 to 7 dry A typical soil description with range in Chroma: 2 or 3 characteristics is included, in alphabetical order, in Texture: Clay loam, loam, silt loam, or silty clay this section. loam Management Clay content: 22 to 35 percent Content of rock fragments: 0 to 35 percent—0 to For management information about this map unit, 5 percent cobbles; 0 to 30 percent pebbles see appropriate sections in Part II of this publication. Calcium carbonate equivalent: 30 to 35 percent Electrical conductivity: 0 to 2 mmhos/cm Reaction: pH 7.9 to 8.4 445—Saypo loam, 0 to 4 percent slopes, rarely flooded C horizon Hue: 7.5YR, 10YR, 2.5Y, or 5Y Setting Value: 4 or 5 moist; 5 or 6 dry Chroma: 2 to 4 Landform: Flood plains Texture: Clay loam or loam Slope: 0 to 4 percent Clay content: 22 to 40 percent Elevation: 3,800 to 5,000 feet Content of rock fragments: 5 to 50 percent—0 to Mean annual precipitation: 10 to 14 inches 10 percent cobbles; 5 to 40 percent pebbles Frost-free period: 90 to 105 days 178 Soil Survey
Composition Water table: Apparent Available water capacity: Mainly 7.9 inches Major Components Saypo and similar soils: 85 percent A typical soil description with range in Minor Components characteristics is included, in alphabetical order, in Gregson soils: 0 to 5 percent this section. Poorly drained soils: 0 to 5 percent Management Soils that have a saline surface: 0 to 5 percent For management information about this map unit, Major Component Description see appropriate sections in Part II of this publication. Surface layer texture: Loam Depth class: Very deep (more than 60 inches) Drainage class: Somewhat poorly drained 545—Saypo loam, 0 to 4 percent slopes Dominant parent material: Alluvium Native plant cover type: Rangeland Setting Flooding: Rare Water table: Apparent Landform: Stream terraces Available water capacity: Mainly 7.9 inches Slope: 0 to 4 percent Elevation: 3,800 to 5,000 feet A typical soil description with range in Mean annual precipitation: 10 to 14 inches characteristics is included, in alphabetical order, in Frost-free period: 90 to 105 days this section. Composition Management Major Components For management information about this map unit, Saypo and similar soils: 85 percent see appropriate sections in Part II of this publication. Minor Components Gregson soils: 0 to 5 percent 535—Saypo loam, cool, Poorly drained soils: 0 to 5 percent 0 to 4 percent slopes Soils that have a saline surface: 0 to 5 percent Major Component Description Setting Surface layer texture: Loam Landform: Stream terraces Depth class: Very deep (more than 60 inches) Slope: 0 to 4 percent Drainage class: Somewhat poorly drained Elevation: 3,800 to 5,000 feet Dominant parent material: Alluvium Mean annual precipitation: 15 to 19 inches Native plant cover type: Rangeland Frost-free period: 70 to 90 days Flooding: None Water table: Apparent Composition Available water capacity: Mainly 7.9 inches Major Components Saypo and similar soils: 85 percent A typical soil description with range in characteristics is included, in alphabetical order, in Minor Components this section. Gregson soils: 0 to 5 percent Poorly drained soils: 0 to 5 percent Management Soils that have a saline surface: 0 to 5 percent For management information about this map unit, Major Component Description see appropriate sections in Part II of this publication. Surface layer texture: Loam Depth class: Very deep (more than 60 inches) Shawmut Series Drainage class: Somewhat poorly drained Dominant parent material: Alluvium Depth class: Very deep Native plant cover type: Rangeland Drainage class: Well drained Flooding: None Permeability: Moderate Powell County Area, Montana—Part I 179
Landform: Mountains, alluvial fans, stream terraces, coarse fragments; violently effervescent; strongly and moraines alkaline; gradual wavy boundary. Parent material: Alluvium and alpine till Bk2—29 to 60 inches; white (10YR 8/2) extremely Slope range: 0 to 60 percent cobbly loam, light gray (10YR 7/2) moist; weak Elevation range: 3,800 to 5,800 feet fine subangular blocky structure; slightly hard, Annual precipitation: 15 to 19 inches friable, slightly sticky, slightly plastic; few very Annual air temperature: 39 to 44 degrees F fine roots; few very fine, fine, and medium pores; Frost-free period: 70 to 90 days 20 percent cobbles and 45 percent pebbles; disseminated lime; violently effervescent; strongly Taxonomic Class: Loamy-skeletal, mixed, alkaline. superactive, frigid Typic Argiustolls Range in Characteristics Typical Pedon Soil temperature: 41 to 47 degrees F Moisture control section: Between depths of 4 and Shawmut gravelly loam, 4 to 8 percent slopes, in an 12 inches area of rangeland, 1,700 feet north and 1,500 feet Thickness of the mollic epipedon: 7 to 16 inches east of the southwest corner of sec. 26, T. 8 N., Depth to the calcic horizon: 9 to 20 inches R. 10 W. Soil phases: Cobbly or bouldery A—0 to 6 inches; dark grayish brown (10YR 4/2) A horizon gravelly loam, very dark grayish brown (10YR Hue: 7.5YR or 10YR 3/2) moist; moderate medium subangular blocky Value: 3 or 4 dry; 2 or 3 moist structure parting to strong medium granular Chroma: 2 or 3 structure; slightly hard, friable, slightly sticky, Clay content: 15 to 27 percent slightly plastic; common very fine and fine roots; Content of rock fragments: 15 to 80 percent—0 to many very fine and common fine and medium 40 percent boulders and stones; 5 to pores; 5 percent cobbles and 15 percent pebbles; 25 percent cobbles; 10 to 50 percent pebbles neutral; clear smooth boundary. Rock fragments, surface cover: 0.01 to 0.1 Bt—6 to 12 inches; brown (10YR 4/3) gravelly clay percent stones or boulders loam, dark brown (10YR 3/3) moist; weak Reaction: pH 6.6 to 7.3 medium prismatic structure parting to moderate medium subangular blocky; hard, firm, Bt horizon moderately sticky and moderately plastic; Hue: 7.5YR or 10YR common very fine and fine roots; many very fine Value: 3 to 5 dry; 2 or 3 moist and fine and common medium pores; common Chroma: 2 or 3 faint clay films on faces of peds; 5 percent Texture: Sandy clay loam or clay loam cobbles and 25 percent pebbles; neutral; clear Clay content: 20 to 35 percent smooth boundary. Content of rock fragments: 15 to 80 percent—0 to Btk—12 to 18 inches; pale brown (10YR 6/3) very 15 percent stones; 0 to 20 percent cobbles; gravelly clay loam, brown (10YR 5/3) moist; weak 15 to 45 percent pebbles medium subangular blocky structure parting to Reaction: pH 6.6 to 7.3 moderate medium granular structure; hard, firm, Btk horizon slightly sticky, slightly plastic; few very fine roots; Hue: 7.5YR or 10YR many very fine and common fine and medium Value: 3 to 6 dry; 2 to 5 moist pores; few faint clay films on faces of peds; Chroma: 2 or 3 10 percent cobbles and 35 percent pebbles; Texture: Clay loam, loam, or sandy loam common medium masses of lime; strongly Clay content: 15 to 30 percent effervescent; moderately alkaline; gradual smooth Content of rock fragments: 35 to 80 percent—0 to boundary. 20 percent stones; 0 to 20 percent cobbles; Bk1—18 to 29 inches; very pale brown (10YR 7/3) 30 to 60 percent pebbles very gravelly loam, pale brown (10YR 6/3) moist; Calcium carbonate equivalent: 15 to 30 percent weak fine subangular blocky structure; slightly Reaction: pH 7.9 to 8.4 hard, friable, slightly sticky, slightly plastic; few very fine roots; few very fine, fine, and medium Bk1 horizon pores; 10 percent cobbles and 35 percent Hue: 2.5Y or 10YR pebbles; common lime casts on underside of Value: 5 to 7 dry; 4 to 6 moist 180 Soil Survey
Chroma: 2 or 3 Flooding: None Texture: Sandy loam or loam Available water capacity: Mainly 4.3 inches Clay content: 15 to 25 percent Content of rock fragments: 35 to 80 percent—0 to A typical soil description with range in 20 percent stones; 0 to 20 percent cobbles; characteristics is included, in alphabetical order, in 30 to 75 percent pebbles this section. Calcium carbonate equivalent: 15 to 25 percent Management Reaction: pH 7.9 to 9.0 For management information about this map unit, Bk2 horizon see appropriate sections in Part II of this publication. Hue: 2.5Y or 10YR Value: 5 to 8 dry; 4 to 7 moist Chroma: 2 or 3 Texture: Sandy loam or loam 51C—Shawmut gravelly loam, Clay content: 5 to 25 percent 4 to 8 percent slopes Content of rock fragments: 50 to 85 percent—0 to 20 percent stones; 0 to 20 percent cobbles; Setting 45 to 70 percent pebbles Landform: Alluvial fans Calcium carbonate equivalent: 10 to 25 percent Slope: 4 to 8 percent Electrical conductivity: Less than 2 mmhos/cm Elevation: 3,800 to 5,800 feet Reaction: pH 7.9 to 9.0 Mean annual precipitation: 15 to 19 inches Frost-free period: 70 to 90 days 51B—Shawmut gravelly loam, Composition 0 to 4 percent slopes Major Components Shawmut and similar soils: 85 percent Setting Minor Components Slopes more than 8 percent: 0 to 4 percent Landform: Alluvial fans and stream terraces Shawmut cobbly loam: 0 to 4 percent Slope: 0 to 4 percent Soils that are clayey throughout: 0 to 4 percent Elevation: 3,800 to 5,800 feet Soils that have a calcareous surface layer: 0 to Mean annual precipitation: 15 to 19 inches 3 percent Frost-free period: 70 to 90 days Major Component Description Composition Surface layer texture: Gravelly loam Major Components Depth class: Very deep (more than 60 inches) Shawmut and similar soils: 85 percent Drainage class: Well drained Minor Components Dominant parent material: Alluvium Shawmut cobbly loam: 0 to 5 percent Native plant cover type: Rangeland Soils that have slopes more than 4 percent: 0 to Flooding: None 5 percent Available water capacity: Mainly 4.3 inches Soils that are clayey throughout: 0 to 5 percent A typical soil description with range in Major Component Description characteristics is included, in alphabetical order, in Surface layer texture: Gravelly loam this section. Depth class: Very deep (more than 60 inches) Management Drainage class: Well drained Dominant parent material: Alluvium For management information about this map unit, Native plant cover type: Rangeland see appropriate sections in Part II of this publication. Powell County Area, Montana—Part I 181
51D—Shawmut gravelly loam, Composition 8 to 15 percent slopes Major Components Shawmut and similar soils: 45 percent Setting Martinsdale and similar soils: 40 percent Landform: Alluvial fans Minor Components Slope: 8 to 15 percent Soils that have slopes more than 4 percent: 0 to Elevation: 3,800 to 5,800 feet 8 percent Mean annual precipitation: 15 to 19 inches Soils that have clayey subsoil: 0 to 7 percent Frost-free period: 70 to 90 days Composition Major Component Description Major Components Shawmut Shawmut and similar soils: 85 percent Surface layer texture: Gravelly loam Depth class: Very deep (more than 60 inches) Minor Components Drainage class: Well drained Soils that have slopes more than 15 percent: 0 to Dominant parent material: Alluvium 4 percent Native plant cover type: Rangeland Shawmut cobbly loam: 0 to 4 percent Flooding: None Soils that are clayey throughout: 0 to 4 percent Available water capacity: Mainly 4.3 inches Soils that have a calcareous surface layer: 0 to 3 percent Martinsdale Major Component Description Surface layer texture: Loam Depth class: Very deep (more than 60 inches) Surface layer texture: Gravelly loam Drainage class: Well drained Depth class: Very deep (more than 60 inches) Dominant parent material: Alluvium Drainage class: Well drained Native plant cover type: Rangeland Dominant parent material: Alluvium Flooding: None Native plant cover type: Rangeland Available water capacity: Mainly 9.1 inches Flooding: None Available water capacity: Mainly 4.3 inches A typical soil description with range in A typical soil description with range in characteristics is included, in alphabetical order, in characteristics is included, in alphabetical order, in this section. this section. Management Management For management information about this map unit, For management information about this map unit, see appropriate sections in Part II of this publication. see appropriate sections in Part II of this publication.
53B—Shawmut-Martinsdale complex, 53C—Shawmut-Martinsdale complex, 0 to 4 percent slopes 4 to 8 percent slopes
Setting Setting Landform: Landform: • Shawmut—Stream terraces • Shawmut—Alluvial fans • Martinsdale—Stream terraces • Martinsdale—Alluvial fans Slope: Slope: • Shawmut—0 to 4 percent • Shawmut—4 to 8 percent • Martinsdale—0 to 4 percent • Martinsdale—4 to 8 percent Elevation: 3,800 to 5,800 feet Elevation: 3,800 to 5,800 feet Mean annual precipitation: 15 to 19 inches Mean annual precipitation: 15 to 19 inches Frost-free period: 70 to 90 days Frost-free period: 70 to 90 days 182 Soil Survey
Composition Minor Components Soils that have slopes more than 8 percent: 0 to Major Components 5 percent Shawmut and similar soils: 45 percent Roy soils: 0 to 5 percent Martinsdale and similar soils: 40 percent Martinsdale soils: 0 to 5 percent Minor Components Major Component Description Soils that have slopes more than 8 percent: 0 to 8 percent Surface layer texture: Cobbly loam Very gravelly clayey soils: 0 to 7 percent Depth class: Very deep (more than 60 inches) Drainage class: Well drained Major Component Description Dominant parent material: Alluvium Shawmut Native plant cover type: Rangeland Surface layer texture: Gravelly loam Flooding: None Depth class: Very deep (more than 60 inches) Available water capacity: Mainly 4.3 inches Drainage class: Well drained Dominant parent material: Alluvium A typical soil description with range in Native plant cover type: Rangeland characteristics is included, in alphabetical order, in Flooding: None this section. Available water capacity: Mainly 4.3 inches Management Martinsdale For management information about this map unit, Surface layer texture: Loam see appropriate sections in Part II of this publication. Depth class: Very deep (more than 60 inches) Drainage class: Well drained Dominant parent material: Alluvium 151D—Shawmut cobbly loam, Native plant cover type: Rangeland 8 to 15 percent slopes Flooding: None Available water capacity: Mainly 9.1 inches Setting A typical soil description with range in Landform: Alluvial fans characteristics is included, in alphabetical order, in Slope: 8 to 15 percent this section. Elevation: 3,800 to 5,800 feet Management Mean annual precipitation: 15 to 19 inches Frost-free period: 70 to 90 days For management information about this map unit, see appropriate sections in Part II of this publication. Composition Major Components 151C—Shawmut cobbly loam, Shawmut and similar soils: 85 percent 4 to 8 percent slopes Minor Components Roy soils: 0 to 8 percent Setting Danvers soils: 0 to 7 percent Landform: Alluvial fans Major Component Description Slope: 4 to 8 percent Elevation: 3,800 to 5,800 feet Surface layer texture: Cobbly loam Mean annual precipitation: 15 to 19 inches Depth class: Very deep (more than 60 inches) Frost-free period: 70 to 90 days Drainage class: Well drained Dominant parent material: Alluvium Composition Native plant cover type: Rangeland Major Components Flooding: None Shawmut and similar soils: 85 percent Available water capacity: Mainly 4.3 inches Powell County Area, Montana—Part I 183
A typical soil description with range in Composition characteristics is included, in alphabetical order, in Major Components this section. Shawmut and similar soils: 85 percent Management Minor Components For management information about this map unit, Roy soils: 0 to 8 percent see appropriate sections in Part II of this publication. Danvers soils: 0 to 7 percent
Major Component Description 151E—Shawmut cobbly loam, 15 to 35 percent slopes Surface layer texture: Cobbly loam Depth class: Very deep (more than 60 inches) Drainage class: Well drained Setting Dominant parent material: Alluvium Landform: Alluvial fans Native plant cover type: Rangeland Slope: 15 to 35 percent Flooding: None Elevation: 3,800 to 5,800 feet Available water capacity: Mainly 4.3 inches Mean annual precipitation: 15 to 19 inches Frost-free period: 70 to 90 days A typical soil description with range in characteristics is included, in alphabetical order, in Composition this section. Major Components Management Shawmut and similar soils: 85 percent For management information about this map unit, Minor Components see appropriate sections in Part II of this publication. Roy soils: 0 to 8 percent Danvers soils: 0 to 7 percent Major Component Description 251D—Shawmut stony loam, Surface layer texture: Cobbly loam 0 to 15 percent slopes Depth class: Very deep (more than 60 inches) Drainage class: Well drained Setting Dominant parent material: Alluvium Native plant cover type: Rangeland Landform: Alluvial fans Flooding: None Slope: 0 to 15 percent Available water capacity: Mainly 4.3 inches Elevation: 3,800 to 5,800 feet Mean annual precipitation: 15 to 19 inches A typical soil description with range in Frost-free period: 70 to 90 days characteristics is included, in alphabetical order, in Composition this section. Major Components Management Shawmut and similar soils: 85 percent For management information about this map unit, Minor Components see appropriate sections in Part II of this publication. Roy soils: 0 to 8 percent Winspect soils: 0 to 7 percent 151F—Shawmut cobbly loam, 35 to 60 percent slopes Major Component Description Surface layer texture: Stony loam Setting Depth class: Very deep (more than 60 inches) Landform: Mountains Drainage class: Well drained Slope: 35 to 60 percent Dominant parent material: Alluvium Elevation: 3,800 to 5,800 feet Native plant cover type: Rangeland Mean annual precipitation: 15 to 19 inches Flooding: None Frost-free period: 70 to 90 days Available water capacity: Mainly 4.8 inches 184 Soil Survey
A typical soil description with range in Composition characteristics is included, in alphabetical order, Major Components in this section. Shawmut and similar soils: 85 percent Management Minor Components For management information about this map unit, Poorly drained soils: 0 to 4 percent see appropriate sections in Part II of this publication. Very gravelly sandy soils: 0 to 4 percent Soils that have slopes more than 25 percent: 0 to 4 percent 251E—Shawmut stony loam, Winspect soils: 0 to 3 percent 15 to 35 percent slopes Major Component Description Setting Surface layer texture: Very bouldery loam Depth class: Very deep (more than 60 inches) Landform: Alluvial fans Drainage class: Well drained Slope: 15 to 35 percent Dominant parent material: Alpine till Elevation: 3,800 to 5,800 feet Native plant cover type: Rangeland Mean annual precipitation: 15 to 19 inches Flooding: None Frost-free period: 70 to 90 days Available water capacity: Mainly 4.5 inches Composition A typical soil description with range in Major Components characteristics is included, in alphabetical order, in Shawmut and similar soils: 85 percent this section. Minor Components Management Roy soils: 0 to 8 percent Winspect soils: 0 to 7 percent For management information about this map unit, see appropriate sections in Part II of this publication. Major Component Description Surface layer texture: Stony loam Depth class: Very deep (more than 60 inches) 451F—Shawmut very bouldery loam, Drainage class: Well drained 25 to 50 percent slopes Dominant parent material: Alluvium Native plant cover type: Rangeland Setting Flooding: None Available water capacity: Mainly 4.8 inches Landform: Moraines Slope: 25 to 50 percent A typical soil description with range in Elevation: 3,800 to 5,800 feet characteristics is included, in alphabetical order, in Mean annual precipitation: 15 to 19 inches this section. Frost-free period: 70 to 90 days Management Composition For management information about this map unit, Major Components see appropriate sections in Part II of this publication. Shawmut and similar soils: 85 percent Minor Components 451E—Shawmut very bouldery loam, Poorly drained soils: 0 to 4 percent 8 to 25 percent slopes Very gravelly sandy soils: 0 to 4 percent Soils that have slopes more than 50 percent: 0 to 4 percent Setting Winspect soils: 0 to 3 percent Landform: Moraines Major Component Description Slope: 8 to 25 percent Elevation: 3,800 to 5,800 feet Surface layer texture: Very bouldery loam Mean annual precipitation: 15 to 19 inches Depth class: Very deep (more than 60 inches) Frost-free period: 70 to 90 days Drainage class: Well drained Powell County Area, Montana—Part I 185
Dominant parent material: Alpine till 651C—Shawmut-Winspect-Water Native plant cover type: Rangeland complex, 2 to 8 percent slopes Flooding: None Available water capacity: Mainly 4.5 inches Setting A typical soil description with range in Landform: characteristics is included, in alphabetical order, in • Shawmut—Moraines this section. • Winspect—Moraines Slope: Management • Shawmut—2 to 8 percent For management information about this map unit, • Winspect—2 to 8 percent see appropriate sections in Part II of this publication. Elevation: 3,800 to 5,500 feet Mean annual precipitation: 15 to 19 inches Frost-free period: 70 to 90 days 551F—Shawmut extremely bouldery loam, Composition 8 to 50 percent slopes Major Components Shawmut and similar soils: 50 percent Setting Winspect and similar soils: 25 percent Landform: Moraines Water: 10 percent Slope: 8 to 50 percent Minor Components Elevation: 3,800 to 5,800 feet Straw soils: 0 to 5 percent Mean annual precipitation: 15 to 19 inches Martinsdale soils: 0 to 5 percent Frost-free period: 70 to 90 days Poorly drained soils: 0 to 5 percent Composition Major Component Description Major Components Shawmut Shawmut and similar soils: 85 percent Surface layer texture: Gravelly loam Minor Components Depth class: Very deep (more than 60 inches) Straw soils in swales: 0 to 5 percent Drainage class: Well drained Quigley soils: 0 to 5 percent Dominant parent material: Alpine till Poorly drained soils: 0 to 3 percent Native plant cover type: Rangeland Areas of open water: 0 to 2 percent Flooding: None Available water capacity: Mainly 4.0 inches Major Component Description Surface layer texture: Extremely bouldery loam Winspect Depth class: Very deep (more than 60 inches) Surface layer texture: Gravelly loam Drainage class: Well drained Depth class: Very deep (more than 60 inches) Dominant parent material: Alpine till Drainage class: Well drained Native plant cover type: Rangeland Dominant parent material: Alpine till Flooding: None Native plant cover type: Rangeland Available water capacity: Mainly 4.3 inches Flooding: None Available water capacity: Mainly 6.1 inches A typical soil description with range in characteristics is included, in alphabetical order, in Water this section. Definition: Areas of open water Management A typical soil description with range in For management information about this map unit, characteristics is included, in alphabetical order, in see appropriate sections in Part II of this publication. this section. 186 Soil Survey
Management A typical soil description with range in characteristics is included, in alphabetical order, in For management information about this map unit, this section. see appropriate sections in Part II of this publication. Management
651E—Shawmut-Winspect-Water For management information about this map unit, complex, 8 to 25 percent slopes see appropriate sections in Part II of this publication.
Setting 651F—Shawmut-Winspect-Water Landform: complex, 25 to 50 percent slopes • Shawmut—Moraines • Winspect—Moraines Setting Slope: • Shawmut—8 to 25 percent Landform: • Winspect—8 to 25 percent • Shawmut—Moraines Elevation: 3,800 to 5,500 feet • Winspect—Moraines Mean annual precipitation: 15 to 19 inches • Water—Moraines Frost-free period: 70 to 90 days Slope: • Shawmut—25 to 50 percent Composition • Winspect—25 to 50 percent Major Components Elevation: 3,800 to 5,500 feet Shawmut and similar soils: 50 percent Mean annual precipitation: 15 to 19 inches Winspect and similar soils: 25 percent Frost-free period: 70 to 90 days Water: 10 percent Composition Minor Components Major Components Straw soils: 0 to 5 percent Shawmut and similar soils: 50 percent Martinsdale soils: 0 to 5 percent Winspect and similar soils: 25 percent Poorly drained soils: 0 to 5 percent Water: 10 percent Major Component Description Minor Components Shawmut Straw soils: 0 to 5 percent Surface layer texture: Gravelly loam Martinsdale soils: 0 to 5 percent Depth class: Very deep (more than 60 inches) Poorly drained soils: 0 to 5 percent Drainage class: Well drained Major Component Description Dominant parent material: Alpine till Native plant cover type: Rangeland Shawmut Flooding: None Surface layer texture: Gravelly loam Available water capacity: Mainly 4.0 inches Depth class: Very deep (more than 60 inches) Drainage class: Well drained Winspect Dominant parent material: Alpine till Surface layer texture: Gravelly loam Native plant cover type: Rangeland Depth class: Very deep (more than 60 inches) Flooding: None Drainage class: Well drained Available water capacity: Mainly 4.0 inches Dominant parent material: Alpine till Native plant cover type: Rangeland Winspect Flooding: None Surface layer texture: Gravelly loam Available water capacity: Mainly 6.1 inches Depth class: Very deep (more than 60 inches) Drainage class: Well drained Water Dominant parent material: Alpine till Definition: Areas of open water Native plant cover type: Rangeland Powell County Area, Montana—Part I 187
Flooding: None of peds; 20 percent pebbles; slightly alkaline; Available water capacity: Mainly 6.1 inches clear wavy boundary. Bt2—23 to 30 inches; light yellowish brown (10YR Water 6/4) gravelly silty clay, yellowish brown (10YR Definition: Areas of open water 5/4) moist; strong medium subangular blocky structure; extremely hard, very firm, slightly sticky, A typical soil description with range in moderately plastic; many very fine, fine, and characteristics is included, in alphabetical order, in medium roots; many very fine and fine this section. continuous pores; few faint clay films on faces of peds; 20 percent pebbles; slightly alkaline; clear Management smooth boundary. For management information about this map unit, Bk1—30 to 39 inches; light yellowish brown (10YR see appropriate sections in Part II of this publication. 6/4) very gravelly clay loam, yellowish brown (10YR 5/4) moist; weak fine subangular blocky structure; hard, friable, moderately sticky and Silverchief Series slightly plastic; 5 percent cobbles and 35 percent pebbles; many segregated masses of lime; Depth class: Very deep violently effervescent; strongly alkaline; gradual Drainage class: Well drained wavy boundary. Permeability: Moderately slow Bk2—39 to 60 inches; light yellowish brown (10YR Landform: Mountains 6/4) very gravelly clay loam, yellowish brown Parent material: Colluvium derived from limestone (10YR 5/4) moist; weak fine subangular blocky and calcareous argillite structure; hard, friable, slightly sticky, moderately Slope range: 8 to 35 percent plastic; few very fine, fine, and coarse roots; Elevation range: 4,300 to 6,000 feet few very fine and fine discontinuous pores; Annual precipitation: 18 to 25 inches 10 percent cobbles and 35 percent pebbles; Annual air temperature: 38 to 42 degrees F disseminated lime; violently effervescent; strongly Frost-free period: 70 to 90 days alkaline. Range in Characteristics Taxonomic Class: Fine, mixed, superactive, frigid Calcic Haplustalfs Soil temperature: 40 to 44 degrees F Moisture control section: Between depths of 4 and Typical Pedon 12 inches Depth to the calcic horizon: 20 to 35 inches Silverchief cobbly loam, in an area of Silverchief- E horizon Trapps complex, 15 to 35 percent slopes, in an area Hue: 7.5YR or 10YR of woodland, 2,900 feet north and 600 feet west of Value: 6 or 7 dry; 5 or 6 moist the southeast corner of sec. 33, T. 11 N., R. 11 W. Chroma: 2 to 4 Oi—1 inch to 0; undecomposed and slightly Clay content: 20 to 27 percent decomposed forest litter. Content of rock fragments: 0 to 30 percent—0 to E—0 to 6 inches; pale brown (10YR 6/3) cobbly loam, 15 percent cobbles; 0 to 15 percent pebbles brown (10YR 5/3) moist; moderate fine granular Reaction: pH 6.1 to 7.3 structure; soft, friable, nonsticky, slightly plastic; Bt horizons many very fine and fine and few medium roots; Hue: 7.5YR, 10YR, or 2.5Y many very fine and fine discontinuous pores; Value: 5 or 6 dry; 4 or 5 moist 10 percent cobbles and 5 percent pebbles; Chroma: 3, 4, or 6 neutral; clear smooth boundary. Clay content: 40 to 60 percent Bt1—6 to 23 inches; light yellowish brown (10YR 6/4) Content of rock fragments: 5 to 35 percent—0 to gravelly silty clay, yellowish brown (10YR 5/4) 15 percent cobbles; 5 to 20 percent pebbles moist; moderate fine subangular blocky structure; Reaction: pH 6.6 to 7.8 very hard, very firm, slightly sticky, moderately plastic; many very fine and fine and common Bk horizons medium roots; many very fine and fine Hue: 7.5YR, 5YR, or 2.5Y discontinuous pores; few faint clay films on faces Value: 5 to 7 dry; 4 to 6 moist 188 Soil Survey
Chroma: 3 or 4 Management Clay content: 30 to 40 percent For management information about this map unit, Content of rock fragments: 15 to 50 percent—0 to see appropriate sections in Part II of this publication. 15 percent cobbles; 15 to 35 percent pebbles Calcium carbonate equivalent: 15 to 35 percent Reaction: pH 7.4 to 8.4 599E—Silverchief-Trapps complex, 15 to 35 percent slopes
599D—Silverchief-Trapps complex, Setting 8 to 15 percent slopes Landform: • Silverchief—Mountains Setting • Trapps—Mountains Slope: Landform: • Silverchief—15 to 35 percent • Silverchief—Mountains • Trapps—15 to 35 percent • Trapps—Mountains Elevation: 4,300 to 6,000 feet Slope: Mean annual precipitation: 18 to 25 inches • Silverchief—8 to 15 percent Frost-free period: 70 to 90 days • Trapps—8 to 15 percent Elevation: 4,300 to 6,000 feet Composition Mean annual precipitation: 18 to 25 inches Major Components Frost-free period: 70 to 90 days Silverchief and similar soils: 45 percent Trapps and similar soils: 40 percent Composition Minor Components Major Components Whitecow soils: 0 to 10 percent Silverchief and similar soils: 45 percent Soils that do not have rock fragments: 0 to 5 percent Trapps and similar soils: 40 percent Major Component Description Minor Components Whitecow soils: 0 to 15 percent Silverchief Surface layer texture: Loam Major Component Description Depth class: Very deep (more than 60 inches) Drainage class: Well drained Silverchief Dominant parent material: Colluvium Surface layer texture: Loam Native plant cover type: Forestland Depth class: Very deep (more than 60 inches) Flooding: None Drainage class: Well drained Available water capacity: Mainly 5.9 inches Dominant parent material: Colluvium Native plant cover type: Forestland Trapps Flooding: None Surface layer texture: Gravelly loam Available water capacity: Mainly 6.1 inches Depth class: Very deep (more than 60 inches) Drainage class: Well drained Trapps Dominant parent material: Colluvium Surface layer texture: Gravelly loam Native plant cover type: Forestland Depth class: Very deep (more than 60 inches) Flooding: None Drainage class: Well drained Available water capacity: Mainly 5.8 inches Dominant parent material: Colluvium Native plant cover type: Forestland A typical soil description with range in Flooding: None characteristics is included, in alphabetical order, in Available water capacity: Mainly 5.8 inches this section. Management A typical soil description with range in characteristics is included, in alphabetical order, in For management information about this map unit, this section. see appropriate sections in Part II of this publication. Powell County Area, Montana—Part I 189
Sixbeacon Series pores; 10 percent cobbles and 60 percent pebbles; disseminated lime; violently Depth class: Very deep effervescent; moderately alkaline. Drainage class: Well drained Range in Characteristics Permeability: Moderate to the 3Bk3 horizon, rapid below Soil temperature: 41 to 46 degrees F Landform: Alluvial fans and stream terraces Moisture control section: Between depths of 4 and Parent material: Alluvium 12 inches; dry in all parts between four-tenths Slope range: 0 to 60 percent and five-tenths of the cumulative days per year Elevation range: 3,800 to 5,200 feet when the soil temperature at a depth of 20 inches Annual precipitation: 10 to 14 inches is 41 degrees F or higher Annual air temperature: 39 to 44 degrees F Thickness of the mollic epipedon: 7 to 15 inches Frost-free period: 90 to 105 days Depth to the calcic horizon: 8 to 13 inches Ap horizon Taxonomic Class: Loamy-skeletal, mixed, Chroma: 2 or 3 superactive, frigid Aridic Haplustolls Clay content: 20 to 27 percent Typical Pedon Content of rock fragments: 15 to 35 percent—0 to 15 percent cobbles; 15 to 20 percent pebbles Sixbeacon gravelly loam, 0 to 4 percent slopes, in Reaction: pH 6.1 to 7.3 an area of irrigated hayland, 100 feet north and 1,000 feet west of the southeast corner of sec. 23, Bw horizon T. 8 N., R. 9 W. Value: 4 or 5 dry; 3 or 4 moist Chroma: 2 to 4 Ap—0 to 4 inches; grayish brown (10YR 5/2) gravelly Clay content: 20 to 27 percent loam, very dark grayish brown (10YR 3/2) moist; Content of rock fragments: 0 to 35 percent—0 to moderate fine granular structure; soft, very 10 percent cobbles; 0 to 25 percent pebbles friable, nonsticky, nonplastic; many fine roots; Reaction: pH 6.6 to 8.4 many fine irregular pores; 15 percent pebbles; neutral; abrupt smooth boundary. Bk1 horizon Bw—4 to 10 inches; brown (10YR 5/3) loam, dark Value: 5 to 8 dry; 4 to 7 moist brown (10YR 3/3) moist; moderate medium Chroma: 1 to 4 subangular blocky structure; hard, friable, slightly Clay content: 20 to 27 percent sticky, slightly plastic; many fine roots; many very Content of rock fragments: 5 to 35 percent—0 to fine and fine tubular pores; 5 percent pebbles; 5 percent cobbles; 5 to 30 percent pebbles neutral; clear wavy boundary. Calcium carbonate equivalent: 5 to 15 percent Bk1—10 to 12 inches; light brownish gray (10YR 6/2) Reaction: pH 7.4 to 8.4 loam, brown (10YR 5/3) moist; weak fine and 2Bk2 horizon medium subangular blocky structure; slightly Value: 7 or 8 dry; 6 or 7 moist hard, very friable, slightly sticky, slightly plastic; Chroma: 2 to 4 common fine roots; many very fine and fine Texture: Sandy loam or loam pores; 10 percent pebbles; disseminated lime; Clay content: 10 to 20 percent strongly effervescent; moderately alkaline; clear Content of rock fragments: 35 to 60 percent—0 to wavy boundary. 10 percent cobbles; 35 to 50 percent pebbles 2Bk2—12 to 24 inches; white (10YR 8/2) very Calcium carbonate equivalent: 20 to 40 percent gravelly sandy loam, light gray (10YR 7/2) moist; Reaction: pH 7.9 to 8.4 weak fine subangular blocky structure; slightly hard, very friable, nonsticky, nonplastic; common 3Bk3 horizon fine roots; many very fine and fine tubular pores; Value: 5 to 7 dry; 4 to 6 moist 50 percent pebbles; disseminated lime; violently Chroma: 2 to 4 effervescent; moderately alkaline; clear wavy Clay content: 0 to 5 percent boundary. Content of rock fragments: 50 to 80 percent— 3Bk3—24 to 60 inches; light gray (10YR 7/2) 10 to 20 percent cobbles; 40 to 60 percent extremely gravelly loamy sand, pale brown (10YR pebbles 6/3) moist; single grain; loose, nonsticky, Calcium carbonate equivalent: 15 to 30 percent nonplastic; few fine roots; many fine irregular Reaction: pH 7.4 to 8.4 190 Soil Survey
137B—Sixbeacon cobbly loam, Major Component Description 0 to 4 percent slopes Surface layer texture: Cobbly loam Depth class: Very deep (more than 60 inches) Setting Drainage class: Well drained Dominant parent material: Alluvium Landform: Alluvial fans and stream terraces Native plant cover type: Rangeland Slope: 0 to 4 percent Flooding: None Elevation: 3,800 to 5,200 feet Available water capacity: Mainly 4.1 inches Mean annual precipitation: 10 to 14 inches Frost-free period: 90 to 105 days A typical soil description with range in Composition characteristics is included, in alphabetical order, in this section. Major Components Sixbeacon and similar soils: 85 percent Management Minor Components For management information about this map unit, Gravelly loam surface: 0 to 8 percent see appropriate sections in Part II of this publication. Cetrack soils: 0 to 7 percent Major Component Description 137D—Sixbeacon cobbly loam, Surface layer texture: Cobbly loam 8 to 15 percent slopes Depth class: Very deep (more than 60 inches) Drainage class: Well drained Dominant parent material: Alluvium Setting Native plant cover type: Rangeland Landform: Alluvial fans Flooding: None Slope: 8 to 15 percent Available water capacity: Mainly 4.1 inches Elevation: 3,800 to 5,200 feet Mean annual precipitation: 10 to 14 inches A typical soil description with range in Frost-free period: 90 to 105 days characteristics is included, in alphabetical order, in Composition this section. Major Components Management Sixbeacon and similar soils: 85 percent For management information about this map unit, Minor Components see appropriate sections in Part II of this publication. Soils that have a gravelly loam surface: 0 to 8 percent Cetrack soils: 0 to 7 percent 137C—Sixbeacon cobbly loam, 4 to 8 percent slopes Major Component Description Surface layer texture: Cobbly loam Setting Depth class: Very deep (more than 60 inches) Drainage class: Well drained Landform: Alluvial fans and stream terraces Dominant parent material: Alluvium Slope: 4 to 8 percent Native plant cover type: Rangeland Elevation: 3,800 to 5,200 feet Flooding: None Mean annual precipitation: 10 to 14 inches Available water capacity: Mainly 4.1 inches Frost-free period: 90 to 105 days Composition A typical soil description with range in characteristics is included, in alphabetical order, in Major Components this section. Sixbeacon and similar soils: 85 percent Management Minor Components Soils that have a gravelly loam surface: 0 to 8 percent For management information about this map unit, Cetrack soils: 0 to 7 percent see appropriate sections in Part II of this publication. Powell County Area, Montana—Part I 191
237B—Sixbeacon gravelly loam, Major Component Description 0 to 4 percent slopes Surface layer texture: Gravelly loam Depth class: Very deep (more than 60 inches) Setting Drainage class: Well drained Dominant parent material: Alluvium Landform: Alluvial fans and stream terraces Native plant cover type: Rangeland Slope: 0 to 4 percent Flooding: None Elevation: 3,800 to 5,200 feet Available water capacity: Mainly 4.1 inches Mean annual precipitation: 10 to 14 inches Frost-free period: 90 to 105 days A typical soil description with range in Composition characteristics is included, in alphabetical order, in this section. Major Components Sixbeacon and similar soils: 85 percent Management Minor Components For management information about this map unit, Anaconda soils: 0 to 10 percent see appropriate sections in Part II of this publication. Soils that have a cobbly loam surface: 0 to 5 percent Major Component Description 5—Slickens-Aquents complex, Surface layer texture: Gravelly loam 0 to 2 percent slopes, Depth class: Very deep (more than 60 inches) occasionally flooded Drainage class: Well drained Dominant parent material: Alluvium Setting Native plant cover type: Rangeland Landform: Flooding: None • Slickens—Flood plains Available water capacity: Mainly 4.1 inches • Aquents—Flood plains Slope: A typical soil description with range in • Slickens—0 to 2 percent characteristics is included, in alphabetical order, in • Aquents—0 to 2 percent this section. Elevation: 3,600 to 5,200 feet Management Mean annual precipitation: 10 to 14 inches Frost-free period: 90 to 105 days For management information about this map unit, see appropriate sections in Part II of this publication. Composition Major Components Slickens: 45 percent 237C—Sixbeacon gravelly loam, Aquents and similar soils: 40 percent 4 to 8 percent slopes Minor Components Very poorly drained soils: 0 to 5 percent Setting Areas of open water: 0 to 5 percent Areas of riverwash: 0 to 5 percent Landform: Alluvial fans and stream terraces Slope: 4 to 8 percent Major Component Description Elevation: 3,800 to 5,200 feet Slickens Mean annual precipitation: 10 to 14 inches Definition: Material from ore mills, commonly freshly Frost-free period: 90 to 105 days ground rock that has undergone chemical Composition treatment during the milling process Flooding: Occasional Major Components Sixbeacon and similar soils: 85 percent Aquents Minor Components Depth class: Very deep (more than 60 inches) Anaconda soils: 0 to 10 percent Drainage class: Poorly drained Soils that have a cobbly loam surface: 0 to 5 percent Dominant parent material: Alluvium 192 Soil Survey
Flooding: Occasional Straw Series Water table: Apparent A typical soil description with range in Depth class: Very deep characteristics is included, in alphabetical order, in Drainage class: Well drained this section. Permeability: Moderate Landform: Drainageways and alluvial fans Management Parent material: Calcareous alluvium and alpine till For management information about this map unit, Slope range: 0 to 25 percent see appropriate sections in Part II of this publication. Elevation range: 3,600 to 5,800 feet Annual precipitation: 15 to 19 inches Annual air temperature: 39 to 44 degrees F 105A—Slickens-Fluvaquentic Frost-free period: 70 to 90 days Endoaquolls complex, 0 to 2 percent slopes, severely impacted Taxonomic Class: Fine-loamy, mixed, superactive, frigid Cumulic Haplustolls Setting Typical Pedon Landform: • Slickens—Flood plains Straw loam, in an area of Quigley-Straw-Water • Fluvaquentic Endoaquolls—Flood plains complex, 2 to 8 percent slopes, in an area of Slope: cropland, 1,000 feet south and 2,300 feet west of the • Slickens—0 to 2 percent northeast corner of sec. 32, T. 14 N., R. 11 W. • Fluvaquentic Endoaquolls—0 to 2 percent Ap—0 to 10 inches; dark grayish brown (10YR 4/2) Elevation: 4,600 to 5,000 feet loam, very dark grayish brown (10YR 3/2) moist; Mean annual precipitation: 10 to 14 inches moderate medium granular structure; soft, friable, Frost-free period: 90 to 105 days slightly sticky, slightly plastic; common very fine Composition and few fine roots; many very fine pores; neutral; clear smooth boundary. Major Components A—10 to 18 inches; dark brown (10YR 4/3) loam, Slickens: 50 percent dark brown (10YR 3/3) moist; weak medium Fluvaquentic Endoaquolls: 35 percent subangular blocky structure parting to moderate Minor Components medium granular structure; slightly hard, friable, Somewhat poorly drained soils: 0 to 10 percent slightly sticky, slightly plastic; few very fine roots; Areas of riverwash: 0 to 5 percent common very fine and fine pores; neutral; gradual smooth boundary. Major Component Description Bw—18 to 25 inches; yellowish brown (10YR 5/4) Slickens loam, dark yellowish brown (10YR 4/4) moist; Definition: Material from ore mills, commonly freshly weak medium subangular blocky structure; ground rock that has undergone chemical slightly hard, very friable, slightly sticky, slightly treatment during the milling process plastic; few fine roots; few very fine pores; neutral; Flooding: Occasional gradual wavy boundary. Bk1—25 to 29 inches; dark yellowish brown (10YR Fluvaquentic Endoaquolls 4/4) loam, dark yellowish brown (10YR 3/4) moist; Depth class: Very deep (more than 60 inches) weak fine subangular blocky structure; soft, very Dominant parent material: Alluvium friable, slightly sticky, slightly plastic; few fine Flooding: Occasional roots; few very fine pores; few fine filaments and Water table: Apparent threads of lime; strongly effervescent; slightly A typical soil description with range in alkaline; clear smooth boundary. characteristics is included, in alphabetical order, in Bk2—29 to 60 inches; pale brown (10YR 6/3) loam, this section. brown (10YR 5/3) moist; weak fine subangular blocky structure; soft, very friable, slightly sticky, Management slightly plastic; few very fine roots; few very fine For management information about this map unit, pores; few fine filaments and threads of lime; see appropriate sections in Part II of this publication. violently effervescent; moderately alkaline. Powell County Area, Montana—Part I 193
Range in Characteristics Minor Components Soils that have very gravelly subsoils: 0 to 10 percent Soil temperature: 42 to 47 degrees F Soils that have slopes more than 4 percent: 0 to Moisture control section: Between depths of 4 and 5 percent 12 inches; not dry in all parts for 60 or more consecutive days following July 1 Major Component Description Thickness of the mollic epipedon: 16 to 40 inches Surface layer texture: Loam Depth to the Bk horizon: 13 to 30 inches Depth class: Very deep (more than 60 inches) A horizons Drainage class: Well drained Hue: 10YR or 2.5Y Dominant parent material: Alluvium Value: 3 or 4 dry; 2 or 3 moist Native plant cover type: Rangeland Chroma: 2 or 3 Flooding: None Clay content: 20 to 27 percent, with less than Available water capacity: Mainly 10.6 inches 15 to 35 percent fine and coarser sand Content of rock fragments: 0 to 10 percent A typical soil description with range in pebbles characteristics is included, in alphabetical order, in Calcium carbonate equivalent: 0 to 5 percent this section. Reaction: pH 6.6 to 8.4 Management Bw horizon For management information about this map unit, Hue: 10YR or 2.5Y see appropriate sections in Part II of this publication. Value: 4 to 6 dry; 3 to 5 moist Chroma: 2 to 4 Texture: Loam, silt loam, silty clay loam, or clay loam Tanna Series Clay content: 22 to 35 percent Depth class: Moderately deep Content of rock fragments: 0 to 10 percent Drainage class: Well drained pebbles Permeability: Slow Reaction: pH 6.6 to 8.4 Landform: Sedimentary plains and hills Bk horizons Parent material: Material derived from Hue: 10YR or 2.5Y semiconsolidated sedimentary beds Value: 4 to 6 dry; 3 to 5 moist Slope range: 0 to 15 percent Chroma: 2 to 4 Elevation range: 3,600 to 5,200 feet Texture: Loam, silt loam, silty clay loam, or clay Annual precipitation: 10 to 14 inches loam Annual air temperature: 39 to 44 degrees F Clay content: 22 to 35 percent Frost-free period: 90 to 110 days Content of rock fragments: 0 to 10 percent pebbles Taxonomic Class: Fine, smectitic, frigid Aridic Calcium carbonate equivalent: 3 to 15 percent Argiustolls Reaction: pH 6.6 to 8.4 Typical Pedon Tanna loam, 4 to 8 percent slopes, in an area of 25B—Straw loam, 0 to 4 percent slopes rangeland, 3,600 feet south and 600 feet west of the northeast corner of sec. 28, T. 9 N., R. 9 W. Setting A—0 to 5 inches; brown (10YR 5/3) loam, dark brown Landform: Alluvial fans (10YR 3/3) moist; moderate medium granular Slope: 0 to 4 percent structure and weak thin platy structure; soft, very Elevation: 3,600 to 5,800 feet friable, slightly sticky, slightly plastic; many very Mean annual precipitation: 15 to 19 inches fine and fine roots; many very fine and fine Frost-free period: 70 to 90 days irregular pores; neutral; clear smooth boundary. BA—5 to 8 inches; brown (10YR 4/3) silty clay loam, Composition dark brown (10YR 3/3) moist; moderate fine Major Components subangular blocky structure parting to moderate Straw and similar soils: 85 percent medium granular structure; slightly hard, friable, 194 Soil Survey
moderately sticky and moderately plastic; many Content of rock fragments: 0 to 10 percent—0 to very fine and fine roots; many very fine and fine 5 percent cobbles; 0 to 5 percent channers irregular and tubular pores; neutral; clear smooth Electrical conductivity: Less than 4 mmhos/cm boundary. Reaction: pH 6.6 to 8.4 Bt—8 to 17 inches; brown (10YR 5/3) silty clay loam, Bk horizon dark brown (10YR 4/3) moist; strong medium Hue: 10YR or 2.5Y prismatic structure parting to strong medium Value: 5 or 6 dry; 4 or 5 moist subangular blocky; very hard, firm, moderately Chroma: 2 or 3 sticky and moderately plastic; common very fine Texture: Clay loam, silty clay loam, or clay roots; few very fine and fine tubular pores; many Clay content: 35 to 50 percent distinct brown (10YR 4/3) clay films on faces of Content of rock fragments: 0 to 10 percent—0 to peds; neutral; clear smooth boundary. 5 percent cobbles; 0 to 5 percent channers Bk—17 to 31 inches; light brownish gray (2.5Y 6/2) Electrical conductivity: 2 to 4 mmhos/cm silty clay loam, grayish brown (2.5Y 5/2) moist; Calcium carbonate equivalent: 5 to 15 percent moderate medium prismatic structure parting to Reaction: pH 7.4 to 8.4 strong medium subangular blocky; very hard, firm, moderately sticky and moderately plastic; few very fine roots; few very fine tubular pores; 65C—Tanna loam, 4 to 8 percent slopes few faint yellowish brown (10YR 5/4) organic cutans on faces of peds; common medium Setting masses of lime; strongly effervescent; moderately alkaline; gradual smooth boundary. Landform: Sedimentary plains Cr—31 to 60 inches; grayish brown (2.5YR 5/2) Slope: 4 to 8 percent semiconsolidated siltstone interbedded with Elevation: 3,600 to 5,200 feet lenses of sandstone. Mean annual precipitation: 10 to 14 inches Frost-free period: 90 to 105 days Range in Characteristics Composition Soil temperature: 40 to 47 degrees F Major Components Moisture control section: Between depths of 4 and Tanna and similar soils: 85 percent 12 inches; dry in some part six-tenths or more of the cumulative days per year when the Minor Components soil temperature at a depth of 20 inches is Soils that are very gravelly below 7 inches: 0 to 41 degrees F or higher 5 percent Thickness of the mollic epipedon: 7 to 12 inches Areas of rock outcrop: 0 to 5 percent (includes part of the argillic horizon) Soils that are shallow: 0 to 5 percent Depth to the Bk horizon: 10 to 20 inches Major Component Description Depth to bedrock: 20 to 40 inches Surface layer texture: Loam A horizon Depth class: Moderately deep (20 to 40 inches) Hue: 10YR or 2.5Y Drainage class: Well drained Value: 2 or 3 moist Dominant parent material: Semiconsolidated Chroma: 2 or 3 sedimentary beds Clay content: 20 to 27 percent Native plant cover type: Rangeland Content of rock fragments: 0 to 10 percent—0 to Flooding: None 5 percent cobbles; 0 to 5 percent channers Available water capacity: Mainly 4.9 inches Reaction: pH 6.6 to 7.8 BA and Bt horizons A typical soil description with range in Hue: 10YR or 2.5Y characteristics is included, in alphabetical order, in Value: 3 or 4 moist this section. Chroma: 2 or 3 Management Texture: Clay loam, silty clay loam, clay, or silty clay For management information about this map unit, Clay content: 35 to 50 percent see appropriate sections in Part II of this publication. Powell County Area, Montana—Part I 195
65D—Tanna loam, 8 to 15 percent slopes Composition Major Components Setting Tanna and similar soils: 65 percent Boxwell and similar soils: 20 percent Landform: Hills Slope: 8 to 15 percent Minor Components Elevation: 3,600 to 5,200 feet Castner soils: 0 to 5 percent Mean annual precipitation: 10 to 14 inches Soils that have channery surface layers: 0 to Frost-free period: 90 to 105 days 5 percent Areas of rock outcrop: 0 to 5 percent Composition Major Components Major Component Description Tanna and similar soils: 85 percent Tanna Minor Components Surface layer texture: Loam Areas of rock outcrop: 0 to 8 percent Depth class: Moderately deep (20 to 40 inches) Soils that are shallow: 0 to 7 percent Drainage class: Well drained Dominant parent material: Semiconsolidated Major Component Description sedimentary beds Surface layer texture: Loam Native plant cover type: Rangeland Depth class: Moderately deep (20 to 40 inches) Flooding: None Drainage class: Well drained Available water capacity: Mainly 4.9 inches Dominant parent material: Semiconsolidated sedimentary beds Boxwell Native plant cover type: Rangeland Surface layer texture: Loam Flooding: None Depth class: Moderately deep (20 to 40 inches) Available water capacity: Mainly 4.9 inches Drainage class: Well drained Dominant parent material: Semiconsolidated A typical soil description with range in sedimentary beds characteristics is included, in alphabetical order, in Native plant cover type: Rangeland this section. Flooding: None Available water capacity: Mainly 6.2 inches Management For management information about this map unit, A typical soil description with range in see appropriate sections in Part II of this publication. characteristics is included, in alphabetical order, in this section. 265C—Tanna-Boxwell loams, Management 4 to 8 percent slopes For management information about this map unit, see appropriate sections in Part II of this publication. Setting Landform: • Tanna—Sedimentary plains 265D—Tanna-Boxwell loams, • Boxwell—Sedimentary plains 8 to 15 percent slopes Slope: • Tanna—4 to 8 percent Setting • Boxwell—4 to 8 percent Elevation: 4,000 to 5,200 feet Landform: Mean annual precipitation: 10 to 14 inches • Tanna—Hills Frost-free period: 90 to 105 days • Boxwell—Hills 196 Soil Survey
Slope: Slope range: 0 to 4 percent • Tanna—8 to 15 percent Elevation range: 3,800 to 6,000 feet • Boxwell—8 to 15 percent Annual precipitation: 10 to 19 inches Elevation: 4,000 to 5,200 feet Annual air temperature: 39 to 44 degrees F Mean annual precipitation: 10 to 14 inches Frost-free period: 70 to 105 days Frost-free period: 90 to 105 days Taxonomic Class: Fine-loamy, mixed, superactive, Composition frigid Aeric Calciaquolls Major Components Typical Pedon Tanna and similar soils: 65 percent Boxwell and similar soils: 20 percent Tetonview loam, 0 to 4 percent slopes, in an area of pasture, 1,100 feet south and 1,400 feet east of the Minor Components northwest corner of sec. 10, T. 6 N., R. 10 W. Castner soils: 0 to 5 percent Soils that have channery surface layers: 0 to A—0 to 9 inches; very dark gray (10YR 3/1) loam, 5 percent gray (10YR 5/1) dry; moderate fine granular Areas of rock outcrop: 0 to 5 percent structure; slightly hard, friable, slightly sticky, moderately plastic; many very fine and fine roots; Major Component Description common very fine and fine pores; violently Tanna effervescent; moderately alkaline; gradual wavy Surface layer texture: Loam boundary. Depth class: Moderately deep (20 to 40 inches) Bkg1—9 to 17 inches; very dark grayish brown (10YR Drainage class: Well drained 3/2) silty clay loam, light brownish gray (10YR Dominant parent material: Semiconsolidated 6/2) dry; few fine distinct dark yellowish brown sedimentary beds (10YR 4/6) redox concentrations; moderate fine Native plant cover type: Rangeland and medium granular structure; hard, friable, Flooding: None slightly sticky, moderately plastic; common very Available water capacity: Mainly 4.9 inches fine and fine roots; few very fine pores; disseminated lime; violently effervescent; Boxwell moderately alkaline; gradual wavy boundary. Surface layer texture: Loam Bkg2—17 to 42 inches; dark grayish brown (10YR Depth class: Moderately deep (20 to 40 inches) 4/2) silty clay loam, light brownish gray (10YR Drainage class: Well drained 6/2) dry; weak fine subangular blocky structure; Dominant parent material: Semiconsolidated hard, friable, slightly sticky, slightly plastic; few sedimentary beds very fine roots; few very fine pores; disseminated Native plant cover type: Rangeland lime; violently effervescent; moderately alkaline; Flooding: None gradual wavy boundary. Available water capacity: Mainly 6.2 inches 2Cg—42 to 60 inches; dark grayish brown (10YR 4/2) very gravelly sandy clay loam, light brownish gray A typical soil description with range in (10YR 6/2) dry; massive; hard, friable, nonsticky, characteristics is included, in alphabetical order, in nonplastic; few very fine roots; few very fine this section. pores; 5 percent cobbles and 30 percent pebbles; strongly effervescent; moderately alkaline. Management Range in Characteristics For management information about this map unit, see appropriate sections in Part II of this publication. Soil temperature: 41 to 47 degrees F Moisture control section: Between depths of 4 and 12 inches Tetonview Series Depth to the seasonal water table: 12 to 24 inches Depth to the calcic horizon: 7 to 13 inches Depth class: Very deep Thickness of the mollic epipedon: 7 to 16 inches Drainage class: Poorly drained Permeability: Moderately slow A horizon Landform: Stream terraces and flood plains Hue: 10YR or 2.5Y Parent material: Calcareous alluvium Value: 2 or 3 moist; 3 to 5 dry Powell County Area, Montana—Part I 197
Chroma: 1 or 2 Elevation: 3,800 to 5,800 feet Clay content: 20 to 27 percent Mean annual precipitation: 10 to 19 inches Content of rock fragments: 0 to 5 percent pebbles Frost-free period: 70 to 105 days Calcium carbonate equivalent: 1 to 5 percent Composition Reaction: pH 7.4 to 8.4 Major Components Bkg1 horizon Tetonview and similar soils: 85 percent Hue: 10YR or 2.5Y Value: 3 to 6 moist; 5 to 7 dry Minor Components Texture: Loam, clay loam, silt loam, or silty clay Blossberg soils: 0 to 3 percent loam Poronto soils: 0 to 3 percent Clay content: 20 to 35 percent Very poorly drained soils: 0 to 3 percent Redox features: None to common; faint to Soils that have a moderately saline surface: 0 to prominent redox concentrations 3 percent Content of rock fragments: 0 to 10 percent Saypo soils: 0 to 3 percent pebbles Major Component Description Calcium carbonate equivalent: 15 to 35 percent Electrical conductivity: 0 to 2 mmhos/cm Surface layer texture: Loam Reaction: pH 7.9 to 8.4 Depth class: Very deep (more than 60 inches) Drainage class: Poorly drained Bkg2 horizon Dominant parent material: Alluvium Hue: 10YR, 2.5Y, or 5Y Native plant cover type: Rangeland Value: 4 to 6 moist; 6 or 7 dry Flooding: None Texture: Loam, clay loam, silt loam, or silty clay Water table: Apparent loam Available water capacity: Mainly 9.2 inches Clay content: 20 to 35 percent Redox features: None to common; faint to many A typical soil description with range in redox concentrations characteristics is included, in alphabetical order, in Content of rock fragments: 0 to 15 percent this section. pebbles Calcium carbonate equivalent: 15 to 35 percent Management Electrical conductivity: 0 to 2 mmhos/cm For management information about this map unit, Reaction: pH 7.9 to 8.4 see appropriate sections in Part II of this publication. 2Cg horizon Hue: 10YR, 2.5Y, or 5Y Value: 4 to 6 moist; 6 or 7 dry 735—Tetonview-Blossberg loams, Texture: Loam, clay loam, sandy clay loam, or silt 0 to 4 percent slopes, rarely flooded loam Clay content: 20 to 30 percent Redox features: None to common; faint to many Setting redox concentrations Landform: Content of rock fragments: 5 to 35 percent—0 to • Tetonview—Flood plains 5 percent cobbles; 5 to 30 percent pebbles • Blossberg—Flood plains Calcium carbonate equivalent: 15 to 30 percent Slope: Electrical conductivity: 0 to 2 mmhos/cm • Tetonview—0 to 4 percent Reaction: pH 7.9 to 8.4 • Blossberg—0 to 4 percent Elevation: 3,800 to 6,000 feet 635—Tetonview loam, Mean annual precipitation: 10 to 19 inches 0 to 4 percent slopes Frost-free period: 70 to 105 days Composition Setting Major Components Landform: Stream terraces Tetonview and similar soils: 45 percent Slope: 0 to 4 percent Blossberg and similar soils: 40 percent 198 Soil Survey
Minor Components Major Component Description Very poorly drained soils: 0 to 10 percent Surface layer texture: Loam Areas of open water: 0 to 5 percent Depth class: Very deep (more than 60 inches) Major Component Description Drainage class: Poorly drained Dominant parent material: Alluvium Tetonview Native plant cover type: Rangeland Surface layer texture: Loam Flooding: Rare Depth class: Very deep (more than 60 inches) Water table: Apparent Drainage class: Poorly drained Available water capacity: Mainly 8.8 inches Dominant parent material: Alluvium Native plant cover type: Rangeland A typical soil description with range in Flooding: Rare characteristics is included, in alphabetical order, in Water table: Apparent this section. Available water capacity: Mainly 9.2 inches Management Blossberg For management information about this map unit, Surface layer texture: Loam see appropriate sections in Part II of this publication. Depth class: Very deep (more than 60 inches) Drainage class: Poorly drained Dominant parent material: Alluvium Tevis Series Native plant cover type: Rangeland Flooding: Rare Depth class: Very deep Water table: Apparent Drainage class: Somewhat excessively drained Available water capacity: Mainly 5.0 inches Permeability: Moderately rapid Landform: Mountains A typical soil description with range in Parent material: Colluvium derived from argillite and characteristics is included, in alphabetical order, in quartzite this section. Slope range: 4 to 80 percent Elevation range: 3,800 to 5,200 feet Management Annual precipitation: 25 to 40 inches For management information about this map unit, Annual air temperature: 38 to 42 degrees F see appropriate sections in Part II of this publication. Frost-free period: 70 to 90 days
Taxonomic Class: Loamy-skeletal, mixed, 835—Tetonview loam, 0 to 4 percent superactive, frigid Dystric Eutrudepts slopes, rarely flooded Typical Pedon Tevis gravelly loam, 35 to 60 percent slopes, in an Setting area of woodland, 500 feet north and 100 feet west of Landform: Flood plains the southeast corner of sec. 8, T. 15 N., R. 11 W. Slope: 0 to 4 percent Oi—2 inches to 0; undecomposed and partially Elevation: 3,800 to 5,800 feet decomposed forest litter. Mean annual precipitation: 10 to 19 inches A—0 to 4 inches; light brownish gray (10YR 6/2) Frost-free period: 70 to 105 days gravelly loam, very dark grayish brown (10YR Composition 3/2) moist; weak fine and medium granular structure; soft, very friable, slightly sticky, slightly Major Components plastic; many fine and medium roots; many fine Tetonview and similar soils: 85 percent and medium irregular pores; 5 percent cobbles Minor Components and 30 percent pebbles; slightly acid; clear wavy Blossberg soils: 0 to 3 percent boundary. Soils that have a peat surface: 0 to 3 percent E1—4 to 9 inches; pale brown (10YR 6/3) very Turrah soils: 0 to 3 percent gravelly loam, brown (10YR 4/3) moist; weak fine Very poorly drained soils: 0 to 3 percent and medium subangular blocky structure; slightly Saypo soils: 0 to 3 percent hard, friable, slightly sticky, slightly plastic; many Powell County Area, Montana—Part I 199
fine and medium roots; many fine and medium Content of rock fragments: 55 to 80 percent—0 to irregular pores; 5 percent cobbles and 50 percent 10 percent cobbles; 55 to 70 percent pebbles pebbles; slightly acid; clear wavy boundary. Reaction: pH 5.6 to 7.3 E2—9 to 23 inches; light gray (10YR 7/2) extremely E/Bw horizon gravelly loam, brown (10YR 5/3) moist; weak fine Hue: E part—10YR or 7.5YR subangular blocky structure; slightly hard, friable, Value: E part—6 or 7 dry, 5 or 6 moist; B part— slightly sticky, slightly plastic; common fine and 5 or 6 dry, 4 or 5 moist medium roots; common fine and medium Chroma: E part—1 to 3; B part—2 to 4 irregular pores; 5 percent cobbles and 60 percent Texture: Sandy loam, fine sandy loam, or loam pebbles; slightly acid; clear wavy boundary. Clay content: 5 to 10 percent E/Bw—23 to 60 inches; 80 percent is light gray (10YR Content of rock fragments: 60 to 85 percent—0 to 7/2) extremely gravelly sandy loam, brown (10YR 10 percent cobbles; 60 to 75 percent pebbles 5/3) moist (E part); 20 percent is pale brown Reaction: pH 6.1 to 7.3 (10YR 6/3) extremely gravelly loam, yellowish brown (10YR 5/4) moist (B part); weak fine and medium subangular blocky structure; soft, very 486D—Tevis gravelly loam, friable, nonsticky, nonplastic; common fine 4 to 15 percent slopes roots; many very fine, fine, and medium pores; 5 percent cobbles and 75 percent pebbles; Setting slightly acid. Landform: Mountains Range in Characteristics Slope: 4 to 15 percent Elevation: 3,800 to 5,200 feet Soil temperature: 40 to 46 degrees F Mean annual precipitation: 25 to 40 inches Moisture control section: Between depths of 4 and Frost-free period: 70 to 90 days 12 inches Composition A horizon Major Components Hue: 10YR or 7.5YR Tevis and similar soils: 85 percent Value: 4 to 6 dry Chroma: 2 or 3 Minor Components Clay content: 10 to 15 percent Hoyt soils: 0 to 5 percent Content of rock fragments: 15 to 35 percent—0 to Soils that have a dark color surface: 0 to 5 percent 5 percent cobbles; 15 to 30 percent pebbles Areas of rock outcrop: 0 to 5 percent Reaction: pH 5.6 to 7.3 Major Component Description E1 horizon Surface layer texture: Gravelly loam Hue: 10YR or 7.5YR Depth class: Very deep (more than 60 inches) Value: 6 or 7 dry; 4 or 5 moist Drainage class: Somewhat excessively drained Chroma: 2 or 3 Dominant parent material: Colluvium Texture: Fine sandy loam, sandy loam, or loam Native plant cover type: Forestland Clay content: 5 to 10 percent Flooding: None Content of rock fragments: 35 to 60 percent—0 to Available water capacity: Mainly 2.7 inches 10 percent cobbles; 35 to 50 percent pebbles Reaction: pH 5.6 to 7.3 A typical soil description with range in E2 horizon characteristics is included, in alphabetical order, in Hue: 10YR or 7.5YR this section. Value: 6 or 7 dry; 4 or 5 moist Management Chroma: 1 to 3 Texture: Fine sandy loam, sandy loam, or loam For management information about this map unit, Clay content: 5 to 10 percent see appropriate sections in Part II of this publication. 200 Soil Survey
486E—Tevis gravelly loam, Minor Components 15 to 35 percent slopes Hoyt soils: 0 to 5 percent Soils that have a dark color surface: 0 to 5 percent Areas of rock outcrop: 0 to 5 percent Setting Major Component Description Landform: Mountains Slope: 15 to 35 percent Surface layer texture: Gravelly loam Elevation: 3,800 to 5,200 feet Depth class: Very deep (more than 60 inches) Mean annual precipitation: 25 to 40 inches Drainage class: Somewhat excessively drained Frost-free period: 70 to 90 days Dominant parent material: Colluvium Native plant cover type: Forestland Composition Flooding: None Major Components Available water capacity: Mainly 2.7 inches Tevis and similar soils: 85 percent A typical soil description with range in Minor Components characteristics is included, in alphabetical order, in Hoyt soils: 0 to 5 percent this section. Soils that have a dark color surface: 0 to 5 percent Areas of rock outcrop: 0 to 5 percent Management Major Component Description For management information about this map unit, see appropriate sections in Part II of this publication. Surface layer texture: Gravelly loam Depth class: Very deep (more than 60 inches) Drainage class: Somewhat excessively drained Tigeron Series Dominant parent material: Colluvium Native plant cover type: Forestland Depth class: Very deep Flooding: None Drainage class: Well drained Available water capacity: Mainly 2.7 inches Permeability: Moderate Landform: Mountains A typical soil description with range in Parent material: Alluvium or colluvium derived from characteristics is included, in alphabetical order, in argillite and quartzite this section. Slope range: 15 to 60 percent Elevation range: 4,600 to 7,000 feet Management Annual precipitation: 20 to 30 inches For management information about this map unit, Annual air temperature: 35 to 38 degrees F see appropriate sections in Part II of this publication. Frost-free period: 30 to 70 days
Taxonomic Class: Loamy-skeletal, mixed, 486F—Tevis gravelly loam, superactive Eutric Haplocryalfs 35 to 60 percent slopes Typical Pedon Setting Tigeron very gravelly loam, 35 to 60 percent slopes, in an area of woodland, 2,600 feet south and Landform: Mountains 2,800 feet east of the northwest corner of sec. 30, Slope: 35 to 60 percent T. 12 N., R. 10 W. Elevation: 3,800 to 5,200 feet Mean annual precipitation: 25 to 40 inches Oe—5 inches to 0; partially decomposed forest litter. Frost-free period: 70 to 90 days E—0 to 9 inches; light brownish gray (10YR 6/2) very gravelly loam, grayish brown (10YR 5/2) moist; Composition strong medium granular structure; slightly hard, Major Components very friable, nonsticky, nonplastic; many very fine Tevis and similar soils: 85 percent and fine and common coarse roots; many very Powell County Area, Montana—Part I 201
fine and fine pores; 45 percent pebbles; Chroma: E part—2 or 3; B part—2 to 4 or 6 moderately acid; gradual wavy boundary. Texture: E part—sandy loam or loam; B part— E and Bt—9 to 15 inches; 60 percent is pinkish gray sandy loam, loam, clay loam, or sandy clay (7.5YR 7/2) extremely gravelly loam, pinkish gray loam (7.5YR 6/2) moist (E part); 40 percent is brown Clay content: E part—10 to 22 percent; B part— (7.5YR 5/4) extremely gravelly loam lamellae 10 to 35 percent 1 3 /4- to /8-inch thick, dark brown (7.5YR 4/4) moist Content of rock fragments: 25 to 70 percent— (B part); weak fine subangular blocky structure; 10 to 25 percent cobbles; 15 to 45 percent slightly hard, very friable, slightly sticky, pebbles moderately plastic; many very fine and fine and Reaction: pH 5.1 to 6.5 common coarse roots; many very fine and fine Bt and E horizon pores; 15 percent cobbles and 45 percent Hue: B part—7.5YR or 10YR; E part—7.5YR or pebbles; slightly acid; gradual wavy boundary. 10YR Bt and E—15 to 42 inches; 70 percent is brown Value: B part—5 or 6 dry, 4 or 5 moist; E part— (7.5YR 5/4) extremely gravelly clay loam lamellae 3 1 6 to 8 dry, 3 to 6 moist /8- to /2-inch thick, dark brown (7.5YR 4/4) moist Chroma: B part—3, 4, or 6; E part—2 or 3 (B part); 30 percent is pinkish gray (7.5YR 7/2) Texture: B part—sandy loam, loam, sandy clay extremely gravelly loam, pinkish gray (7.5YR 6/2) loam, or clay loam; E part—sandy loam or moist (E part); weak fine subangular blocky loam structure; slightly hard, very friable, slightly sticky, Clay content: B part—15 to 35 percent; E part— moderately plastic; many very fine and fine roots; 10 to 22 percent many very fine and fine pores; few faint clay Content of rock fragments: 40 to 80 percent— films on faces of peds; 15 percent cobbles and 10 to 30 percent cobbles; 30 to 50 percent 50 percent pebbles; slightly acid; gradual wavy pebbles boundary. Reaction: pH 5.1 to 6.5 Bt—42 to 60 inches; strong brown (7.5YR 5/6) extremely gravelly clay loam, strong brown Bt horizon (7.5YR 4/6) moist; moderate fine subangular Hue: 7.5YR or 10YR blocky structure; hard, friable, slightly sticky, Value: 5 to 7 dry; 4 to 6 moist moderately plastic; many very fine and fine roots; Chroma: 2 to 4 or 6 many very fine and fine pores; few faint clay Texture: Sandy loam, sandy clay loam, clay loam, films on faces of peds; 20 percent cobbles and or loam 55 percent pebbles; slightly acid. Clay content: 15 to 35 percent Content of rock fragments: 60 to 85 percent— Range in Characteristics 20 to 30 percent cobbles; 40 to 55 percent Soil temperature: 40 to 47 degrees F pebbles Moisture control section: Between depths of 8 and Reaction: pH 5.1 to 6.5 24 inches Depth to the argillic horizon: 13 to 24 inches E horizon 93E—Tigeron very gravelly loam, Hue: 7.5YR or 10YR 15 to 35 percent slopes Value: 6 to 8 dry; 3 to 6 moist Chroma: 2 or 3 Setting Clay content: 10 to 20 percent Landform: Mountains Content of rock fragments: 35 to 60 percent—0 to Slope: 15 to 35 percent 15 percent cobbles; 35 to 45 percent channers Elevation: 4,600 to 7,000 feet Reaction: pH 5.1 to 6.5 Mean annual precipitation: 20 to 30 inches E and Bt horizon Frost-free period: 30 to 70 days Hue: E part—7.5YR or 10YR; B part—7.5YR or Composition 10YR Value: E part—6 to 8 dry, 3 to 6 moist; B part— Major Components 5 or 6 dry, 4 or 5 moist Tigeron and similar soils: 85 percent 202 Soil Survey
Minor Components Management Areas of rock outcrop: 0 to 8 percent For management information about this map unit, Loberg soils: 0 to 7 percent see appropriate sections in Part II of this publication. Major Component Description Surface layer texture: Very gravelly loam Depth class: Very deep (more than 60 inches) Tolbert Series Drainage class: Well drained Depth class: Shallow Dominant parent material: Alluvium or colluvium Drainage class: Well drained Native plant cover type: Forestland Permeability: Moderate Flooding: None Landform: Mountains Available water capacity: Mainly 4.4 inches Parent material: Material derived from fine-grained igneous rocks A typical soil description with range in Slope range: 8 to 60 percent characteristics is included, in alphabetical order, in Elevation range: 3,800 to 5,600 feet this section. Annual precipitation: 15 to 19 inches Management Annual air temperature: 39 to 44 degrees F Frost-free period: 70 to 90 days For management information about this map unit, see appropriate sections in Part II of this publication. Taxonomic Class: Loamy-skeletal, mixed, superactive, frigid Lithic Argiustolls 93F—Tigeron very gravelly loam, Typical Pedon 35 to 60 percent slopes Tolbert very stony loam, in an area of Braziel-Tolbert complex, 15 to 35 percent slopes, in an area of Setting rangeland, 1,900 feet south and 1,500 feet east of Landform: Mountains the northwest corner of sec. 21, T. 8 N., R. 8 W. Slope: 35 to 60 percent A—0 to 5 inches; brown (7.5YR 4/2) very stony loam, Elevation: 4,600 to 7,000 feet dark brown (7.5YR 3/2) moist; moderate fine Mean annual precipitation: 20 to 30 inches granular structure; soft, very friable, nonsticky, Frost-free period: 30 to 70 days nonplastic; many very fine and fine roots; many Composition very fine and fine interstitial pores; 30 percent stones and 15 percent cobbles; neutral; clear Major Components smooth boundary. Tigeron and similar soils: 85 percent Bt—5 to 12 inches; dark reddish gray (5YR 4/2) very Minor Components gravelly loam, dark reddish brown (5YR 2/2) Areas of rock outcrop: 0 to 8 percent moist; weak fine subangular blocky structure; Loberg soils: 0 to 7 percent slightly hard, friable, slightly sticky, slightly plastic; many very fine and fine roots; many very fine and Major Component Description fine interstitial pores; few faint clay films on faces Surface layer texture: Very gravelly loam of peds and lining pores; 15 percent cobbles and Depth class: Very deep (more than 60 inches) 35 percent pebbles; slightly alkaline. Drainage class: Well drained R—12 inches; fine-grained igneous bedrock. Dominant parent material: Alluvium or colluvium Native plant cover type: Forestland Range in Characteristics Flooding: None Available water capacity: Mainly 4.4 inches Soil temperature: 40 to 44 degrees F Moisture control section: Between depths of 4 and A typical soil description with range in 12 inches characteristics is included, in alphabetical order, in Thickness of the mollic epipedon: 7 to 16 inches this section. Depth to the lithic contact: 10 to 20 inches Powell County Area, Montana—Part I 203
A horizon slightly hard, friable, nonsticky, slightly plastic; Hue: 5Y, 2.5Y, 10YR, or 7.5YR many very fine and fine and few medium roots; Value: 3 to 5 dry; 2 or 3 moist many very fine and fine irregular pores; few faint Chroma: 2 or 3 clay films on faces of peds; 5 percent flagstones Clay content: 15 to 25 percent and 40 percent channers; slightly alkaline; clear Coarse fragments: 35 to 60 percent—20 to smooth boundary. 30 percent stones; 10 to 20 percent cobbles; Bt2—15 to 23 inches; reddish yellow (7.5YR 6/6) very 0 to 10 percent pebbles channery clay loam, strong brown (7.5YR 5/6) Reaction: pH 6.1 to 7.8 moist; moderate medium granular structure; slightly hard, friable, slightly sticky, moderately Bt horizon plastic; many very fine and fine roots; many very Hue: 2.5Y, 10YR, 7.5YR, or 5YR fine and fine irregular pores; many faint clay Value: 3 to 6 dry; 2 to 4 moist films on faces of peds; 5 percent flagstones and Chroma: 2 to 4 45 percent channers; slightly alkaline; clear Texture: Clay loam, loam, or sandy clay loam smooth boundary. Clay content: 23 to 27 percent Bk—23 to 60 inches; yellow (10YR 8/8) extremely Coarse fragments: 35 to 65 percent—15 to channery loam, yellowish brown (10YR 5/8) 30 percent cobbles; 20 to 35 percent pebbles moist; moderate medium granular structure; soft, Reaction: pH 6.1 to 7.8 very friable, nonsticky, nonplastic; many very fine and fine roots; many very fine and fine irregular Trapps Series pores; 15 percent flagstones and 50 percent channers; disseminated lime with lime casts on Depth class: Very deep underside of coarse fragments; violently Drainage class: Well drained effervescent; moderately alkaline. Permeability: Moderately slow to the Bk horizon, Range in Characteristics moderate below Landform: Mountains and moraines Soil temperature: 40 to 47 degrees F Parent material: Colluvium derived from limestone Moisture control section: Between depths of 4 and and calcareous argillite and alpine till 12 inches Slope range: 4 to 80 percent Depth to the Bk horizon: 15 to 35 inches Elevation range: 4,000 to 6,500 feet E horizon Annual precipitation: 18 to 25 inches Value: 6 or 7 dry; 5 or 6 moist Annual air temperature: 38 to 42 degrees F Chroma: 2 to 4 Frost-free period: 70 to 90 days Clay content: 10 to 15 percent Content of rock fragments: 15 to 35 percent—0 to Taxonomic Class: Loamy-skeletal, mixed, 20 percent stones, flagstones, and cobbles; superactive, frigid Typic Haplustalfs 15 to 25 percent pebbles or channers Typical Pedon Reaction: pH 5.6 to 7.3 Trapps channery loam, 4 to 25 percent slopes, in an Bt horizons area of woodland, 2,300 feet north and 2,100 feet Hue: 7.5YR, 10YR, or 2.5Y east of the southwest corner of sec. 15, T. 14 N., Value: 5 to 7 dry; 3 to 5 moist R. 10 W. Chroma: 2 to 4 or 6 Clay content: 27 to 35 percent Oi—1 inch to 0; partially decomposed forest litter. Content of rock fragments: 35 to 60 percent—0 to E—0 to 6 inches; light gray (10YR 7/2) channery 10 percent flagstones or cobbles; 35 to loam, brown (10YR 5/3) moist; moderate medium 50 percent pebbles or channers granular structure; soft, very friable, nonsticky, Reaction: pH 6.6 to 8.4 nonplastic; many very fine and fine and common coarse roots; many very fine and fine irregular Bk horizon pores; 5 percent flagstones and 20 percent Hue: 7.5YR, 10YR, or 2.5Y channers; neutral; gradual smooth boundary. Value: 6 to 8 dry; 5 or 6 moist Bt1—6 to 15 inches; reddish yellow (7.5YR 7/6) very Chroma: 2 to 4, 6, or 8 channery clay loam, strong brown (7.5YR 5/6) Texture: Loam or sandy loam moist; weak fine subangular blocky structure; Clay content: 10 to 15 percent 204 Soil Survey
Content of rock fragments: 35 to 60 percent—0 to Mean annual precipitation: 18 to 25 inches 20 percent stones, flagstones, and cobbles; Frost-free period: 70 to 90 days 35 to 50 percent pebbles or channers Composition Calcium carbonate equivalent: 10 to 40 percent Reaction: pH 7.9 to 8.4 Major Components Trapps and similar soils: 85 percent 98E—Trapps gravelly loam, Minor Components 15 to 35 percent slopes Soils that have slopes more than 60 percent: 0 to 4 percent Soils that have dark surfaces: 0 to 4 percent Setting Very gravelly soils: 0 to 3 percent Landform: Mountains Soils that have a calcareous surface: 0 to 3 percent Slope: 15 to 35 percent Major Component Description Elevation: 4,300 to 6,200 feet Mean annual precipitation: 18 to 25 inches Surface layer texture: Gravelly loam Frost-free period: 70 to 90 days Depth class: Very deep (more than 60 inches) Drainage class: Well drained Composition Dominant parent material: Colluvium Major Components Native plant cover type: Forestland Trapps and similar soils: 85 percent Flooding: None Available water capacity: Mainly 4.0 inches Minor Components Soils that have slopes more than 35 percent: 0 to A typical soil description with range in 4 percent characteristics is included, in alphabetical order, in Soils that have dark surfaces: 0 to 4 percent this section. Very gravelly soils: 0 to 3 percent Soils that have a calcareous surface: 0 to 3 percent Management Major Component Description For management information about this map unit, see appropriate sections in Part II of this publication. Surface layer texture: Gravelly loam Depth class: Very deep (more than 60 inches) Drainage class: Well drained 198E—Trapps-Yreka stony loams, Dominant parent material: Colluvium 8 to 25 percent slopes Native plant cover type: Forestland Flooding: None Setting Available water capacity: Mainly 4.0 inches Landform: A typical soil description with range in • Trapps—Moraines characteristics is included, in alphabetical order, in • Yreka—Moraines this section. Slope: • Trapps—8 to 25 percent Management • Yreka—8 to 25 percent For management information about this map unit, Elevation: 4,000 to 6,500 feet see appropriate sections in Part II of this publication. Mean annual precipitation: 18 to 24 inches Frost-free period: 70 to 90 days 98F—Trapps gravelly loam, Composition 35 to 60 percent slopes Major Components Trapps and similar soils: 45 percent Setting Yreka and similar soils: 40 percent Landform: Mountains Minor Components Slope: 35 to 60 percent Bignell soils: 0 to 4 percent Elevation: 4,300 to 6,200 feet Soils that have a calcareous surface: 0 to 4 percent Powell County Area, Montana—Part I 205
Soils that have bouldery surface layers: 0 to 4 percent Major Component Description Soils that have slopes more than 25 percent: 0 to Surface layer texture: Channery loam 3 percent Depth class: Very deep (more than 60 inches) Major Component Description Drainage class: Well drained Dominant parent material: Colluvium Trapps Native plant cover type: Forestland Surface layer texture: Stony loam Flooding: None Depth class: Very deep (more than 60 inches) Available water capacity: Mainly 4.0 inches Drainage class: Well drained Dominant parent material: Alpine till A typical soil description with range in Native plant cover type: Forestland characteristics is included, in alphabetical order, in Flooding: None this section. Available water capacity: Mainly 5.3 inches Management Yreka For management information about this map unit, Surface layer texture: Stony loam see appropriate sections in Part II of this publication. Depth class: Very deep (more than 60 inches) Drainage class: Well drained Dominant parent material: Alpine till 298F—Trapps channery loam, Native plant cover type: Forestland 25 to 60 percent slopes Flooding: None Available water capacity: Mainly 5.6 inches Setting A typical soil description with range in Landform: Mountains characteristics is included, in alphabetical order, in Slope: 25 to 60 percent this section. Elevation: 4,300 to 6,200 feet Mean annual precipitation: 18 to 25 inches Management Frost-free period: 70 to 90 days For management information about this map unit, Composition see appropriate sections in Part II of this publication. Major Components Trapps and similar soils: 85 percent 298D—Trapps channery loam, Minor Components 4 to 25 percent slopes Areas of rock outcrop: 0 to 4 percent Soils that are moderately deep: 0 to 4 percent Setting Yreka soils: 0 to 4 percent Soils that have slopes more than 60 percent: 0 to Landform: Mountains 3 percent Slope: 4 to 25 percent Elevation: 4,300 to 6,200 feet Major Component Description Mean annual precipitation: 18 to 25 inches Surface layer texture: Channery loam Frost-free period: 70 to 90 days Depth class: Very deep (more than 60 inches) Composition Drainage class: Well drained Dominant parent material: Colluvium Major Components Native plant cover type: Forestland Trapps and similar soils: 85 percent Flooding: None Minor Components Available water capacity: Mainly 4.0 inches Yreka soils: 0 to 5 percent Soils that have slopes more than 15 percent: 0 to A typical soil description with range in 5 percent characteristics is included, in alphabetical order, in Bignell soils: 0 to 5 percent this section. 206 Soil Survey
Management Taxonomic Class: Fine, mixed, superactive, frigid Cumulic Endoaquolls For management information about this map unit, see appropriate sections in Part II of this publication. Typical Pedon Turrah silty clay loam, 0 to 4 percent slopes, in an area of pasture, 1,800 feet south and 2,000 feet west 298G—Trapps channery loam, of the northeast corner of sec. 31, T. 13 N., R. 10 W. 60 to 80 percent slopes Oe—2 inches to 0; partially decomposed organic matter. Setting A1—0 to 8 inches; black (10YR 2/1) silty clay loam, Landform: Mountains very dark gray (10YR 3/1) dry; moderate fine Slope: 60 to 80 percent granular structure; hard, firm, moderately sticky Elevation: 4,300 to 6,200 feet and moderately plastic; many very fine and fine Mean annual precipitation: 18 to 25 inches roots; many very fine and fine pores; neutral; Frost-free period: 70 to 90 days clear smooth boundary. A2—8 to 12 inches; black (10YR 2/1) silty clay loam, Composition very dark gray (10YR 3/1) dry; common fine Major Components distinct dark yellowish brown (10YR 4/6) redox Trapps and similar soils: 85 percent concentrations; moderate medium subangular blocky structure; hard, firm, moderately sticky and Minor Components very plastic; common very fine and fine roots; Areas of rock outcrop: 0 to 5 percent common very fine and fine pores; neutral; clear Soils that are moderately deep: 0 to 5 percent smooth boundary. Yreka soils: 0 to 5 percent Bg1—12 to 25 inches; very dark gray (10YR 3/1) silty Major Component Description clay, dark gray (10YR 4/1) dry; common fine distinct dark yellowish brown (10YR 4/6) redox Surface layer texture: Channery loam concentrations; moderate medium subangular Depth class: Very deep (more than 60 inches) blocky structure; very hard, very firm, moderately Drainage class: Well drained sticky and very plastic; common very fine and fine Dominant parent material: Colluvium roots; common very fine and fine pores; slightly Native plant cover type: Forestland alkaline; clear smooth boundary. Flooding: None Bg2—25 to 38 inches; dark gray (10YR 4/1) silty clay, Available water capacity: Mainly 4.0 inches gray (10YR 5/1) dry; common fine and medium distinct dark yellowish brown (10YR 4/4) dry A typical soil description with range in redox concentrations; moderate medium characteristics is included, in alphabetical order, in subangular blocky structure; very hard, very firm, this section. moderately sticky and very plastic; common very Management fine and fine roots; common very fine pores; slightly alkaline; abrupt smooth boundary. For management information about this map unit, 2Cg—38 to 60 inches; dark grayish brown (2.5Y 4/2) see appropriate sections in Part II of this publication. very gravelly sandy clay loam, grayish brown (2.5Y 5/2) dry; common medium distinct dark Turrah Series yellowish brown (10YR 4/6) dry redox concentrations; massive; very hard, firm, Depth class: Very deep moderately sticky and very plastic; 40 percent Drainage class: Poorly drained pebbles; slightly alkaline. Permeability: Slow Range in Characteristics Landform: Stream terraces Parent material: Alluvium Soil temperature: 41 to 47 degrees F Slope range: 0 to 4 percent Moisture control section: Between depths of 4 and Elevation range: 3,800 to 5,000 feet 12 inches Annual precipitation: 15 to 19 inches Thickness of the mollic epipedon: 24 to 48 inches Annual air temperature: 39 to 44 degrees F Depth to the seasonal high water table: 12 to Frost-free period: 70 to 90 days 24 inches Powell County Area, Montana—Part I 207
A1 horizon Minor Components Hue: 10YR, 2.5Y, or 5Y Poronto soils: 0 to 5 percent Value: 2, 2.5, or 3 moist; 2 to 4 dry Very poorly drained soils: 0 to 5 percent Chroma: 1 or 2 Soils that are calcareous throughout: 0 to 5 percent Clay content: 27 to 40 percent Major Component Description Reaction: pH 5.6 to 7.3 Surface layer texture: Silty clay loam A2 horizon Depth class: Very deep (more than 60 inches) Hue: 10YR, 2.5Y, or 5Y Drainage class: Poorly drained Value: 2, 2.5, or 3 moist; 2 to 4 dry Dominant parent material: Alluvium Chroma: 1 or 2 Native plant cover type: Rangeland Redox concentrations: 10YR 4/3, 10YR 4/4, Flooding: None 10YR 4/6, 10YR 5/6, 10YR 6/4, or 10YR 6/6 Water table: Apparent Texture: Clay, silty clay loam, or silty clay Available water capacity: Mainly 7.8 inches Clay content: 35 to 60 percent Reaction: pH 5.6 to 7.3 A typical soil description with range in Bg horizons characteristics is included, in alphabetical order, in Hue: 10YR, 2.5Y, or 5Y this section. Value: 2, 2.5, 3 to 5 moist; 4 to 6 dry Management Chroma: 0 to 3 Redox concentrations: 10YR 4/4, 10YR 4/6, For management information about this map unit, 10YR 5/6, 10YR 6/4, 10YR 6/6, or 7.5YR 5/6 see appropriate sections in Part II of this publication. Texture: Clay, silty clay, silty clay loam, or clay loam Clay content: 35 to 60 percent Varney Series Reaction: pH 6.6 to 7.8 Depth class: Very deep 2Cg horizon Drainage class: Well drained Hue: 2.5Y or 5Y Permeability: Moderate Value: 4 or 5 moist; 4 to 6 dry Landform: Alluvial fans and stream terraces Chroma: 1 or 2 Parent material: Alluvium Redox concentrations: 10YR 6/6, 10YR 4/6, or Slope range: 0 to 50 percent 10YR 4/4 Elevation range: 4,000 to 5,800 feet Texture: Sandy clay loam, sandy loam, or clay Annual precipitation: 10 to 14 inches loam Annual air temperature: 39 to 44 degrees F Clay content: 20 to 40 percent Frost-free period: 90 to 105 days Content of rock fragments: 35 to 60 percent pebbles Taxonomic Class: Fine-loamy, mixed, superactive, Reaction: pH 6.6 to 7.8 frigid Calcidic Argiustolls Typical Pedon 649—Turrah silty clay loam, Varney loam, in an area of Varney-Con loams, 4 to 0 to 4 percent slopes 8 percent slopes, in an area of cropland, 600 feet south and 1,800 feet east of the northwest corner of Setting sec. 30, T. 7 N., R. 9 W. Landform: Stream terraces Ap—0 to 7 inches; brown (10YR 5/3) loam, dark Slope: 0 to 4 percent brown (10YR 3/3) moist; weak medium granular Elevation: 3,800 to 5,000 feet structure; soft, very friable, nonsticky, nonplastic; Mean annual precipitation: 15 to 19 inches many very fine and fine roots; many fine irregular Frost-free period: 70 to 90 days pores; 5 percent pebbles; neutral; abrupt smooth boundary. Composition Bt—7 to 12 inches; yellowish brown (10YR 5/4) clay Major Components loam, dark yellowish brown (10YR 4/4) moist; Turrah and similar soils: 85 percent moderate medium prismatic structure parting to 208 Soil Survey
moderate medium subangular blocky; hard, Texture: Clay loam or sandy clay loam friable, moderately sticky and moderately plastic; Clay content: 27 to 35 percent many very fine and fine roots; many very fine and Content of rock fragments: 5 to 35 percent—0 to fine tubular pores; many distinct dark brown 10 percent cobbles; 5 to 30 percent pebbles (10YR 3/3) clay films on faces of peds; 5 percent Electrical conductivity: 0 to 2 mmhos/cm pebbles; neutral; clear smooth boundary. Reaction: pH 6.6 to 7.8 Bk1—12 to 16 inches; pale brown (10YR 6/3) loam, Bk1 horizon yellowish brown (10YR 5/4) moist; weak medium Hue: 10YR or 2.5Y subangular blocky structure; hard, friable, Value: 5 to 8 dry; 4 to 7 moist moderately sticky and moderately plastic; many Chroma: 2 to 4 fine roots; many fine tubular pores; 5 percent Texture: Sandy loam, loam, clay loam, or sandy pebbles; common fine masses of lime; strongly clay loam effervescent; moderately alkaline; clear wavy Clay content: 10 to 30 percent boundary. Content of rock fragments: 5 to 35 percent—0 to Bk2—16 to 28 inches; very pale brown (10YR 7/3) 5 percent cobbles; 5 to 30 percent pebbles loam, pale brown (10YR 6/3) moist; weak fine Calcium carbonate equivalent: 15 to 30 percent subangular blocky structure; slightly hard, very Electrical conductivity: 0 to 2 mmhos/cm friable, slightly sticky, nonplastic; common fine Reaction: pH 7.4 to 8.4 roots; common very fine and fine tubular and irregular pores; 5 percent pebbles; disseminated Bk2 horizon lime; violently effervescent; moderately alkaline; Hue: 10YR or 2.5Y gradual wavy boundary. Value: 6 to 8 dry; 4 to 7 moist Bk3—28 to 60 inches; very pale brown (10YR 7/4) Chroma: 3 or 4 gravelly sandy loam, dark yellowish brown (10YR Texture: Sandy loam, loam, or sandy clay loam 4/4) moist; weak fine subangular blocky structure; Clay content: 10 to 30 percent slightly hard, very friable, nonsticky, nonplastic; Content of rock fragments: 5 to 35 percent—0 to few very fine roots; many fine tubular and 5 percent cobbles; 5 to 30 percent pebbles irregular pores; 15 percent pebbles; disseminated Calcium carbonate equivalent: 15 to 30 percent lime; strongly effervescent; moderately alkaline. Electrical conductivity: 0 to 2 mmhos/cm Reaction: pH 7.4 to 8.4 Range in Characteristics Bk3 horizon Soil temperature: 40 to 47 degrees F Hue: 2.5Y, 10YR, or 7.5YR Moisture control section: Between depths of 4 and Value: 5 to 7 dry; 4 to 6 moist 12 inches; dry in all parts between four-tenths Chroma: 2 to 4 and five-tenths of the cumulative days per Texture: Loamy sand stratified with loam or sandy year when the soil temperature at 20 inches is loam 41 degrees F or higher Clay content: 5 to 15 percent Thickness of the mollic epipedon: 7 to 16 inches Content of rock fragments: 5 to 35 percent—0 to Depth to the Bk horizon: 9 to 20 inches 5 percent cobbles; 5 to 30 percent pebbles Ap horizon Electrical conductivity: 0 to 2 mmhos/cm Hue: 10YR or 2.5Y Calcium carbonate equivalent: 1 to 15 percent Value: 4 or 5 dry; 2 or 3 moist Reaction: pH 7.9 to 8.4 Chroma: 2 or 3 Texture: Clay loam, loam, or sandy clay loam Clay content: 18 to 35 percent 31B—Varney clay loam, Content of rock fragments: 0 to 35 percent—0 to 0 to 4 percent slopes 10 percent cobbles; 0 to 25 percent pebbles Electrical conductivity: 0 to 2 mmhos/cm Setting Reaction: pH 5.6 to 7.3 Landform: Alluvial fans and stream terraces Bt horizon Slope: 0 to 4 percent Hue: 10YR or 2.5Y Elevation: 4,000 to 5,200 feet Value: 4 to 6 dry; 3 to 5 moist Mean annual precipitation: 10 to 14 inches Chroma: 2 to 4 Frost-free period: 90 to 105 days Powell County Area, Montana—Part I 209
Composition Drainage class: Well drained Dominant parent material: Alluvium Major Components Native plant cover type: Rangeland Varney and similar soils: 85 percent Flooding: None Minor Components Available water capacity: Mainly 6.8 inches Sandy soils that are on summits: 0 to 10 percent Varney very gravelly loam: 0 to 5 percent A typical soil description with range in characteristics is included, in alphabetical order, in Major Component Description this section. Surface layer texture: Clay loam Management Depth class: Very deep (more than 60 inches) Drainage class: Well drained For management information about this map unit, Dominant parent material: Alluvium see appropriate sections in Part II of this publication. Native plant cover type: Rangeland Flooding: None Available water capacity: Mainly 6.8 inches 31D—Varney clay loam, 8 to 15 percent slopes A typical soil description with range in characteristics is included, in alphabetical order, in this section. Setting Management Landform: Alluvial fans Slope: 8 to 15 percent For management information about this map unit, Elevation: 4,000 to 5,200 feet see appropriate sections in Part II of this publication. Mean annual precipitation: 10 to 14 inches Frost-free period: 90 to 105 days 31C—Varney clay loam, Composition 4 to 8 percent slopes Major Components Varney and similar soils: 85 percent Setting Minor Components Landform: Alluvial fans and stream terraces Very cobbly loam soils: 0 to 10 percent Slope: 4 to 8 percent Very gravelly soils that are on summits: 0 to 5 percent Elevation: 4,000 to 5,200 feet Mean annual precipitation: 10 to 14 inches Major Component Description Frost-free period: 90 to 105 days Surface layer texture: Clay loam Composition Depth class: Very deep (more than 60 inches) Drainage class: Well drained Major Components Dominant parent material: Alluvium Varney and similar soils: 85 percent Native plant cover type: Rangeland Minor Components Flooding: None Soils that have a very gravelly clay subsurface: 0 to Available water capacity: Mainly 6.8 inches 5 percent Varney cobbly loam on summits: 0 to 5 percent A typical soil description with range in Soils that have a very gravelly loam subsurface: 0 to characteristics is included, in alphabetical order, in 5 percent this section. Major Component Description Management Surface layer texture: Clay loam For management information about this map unit, Depth class: Very deep (more than 60 inches) see appropriate sections in Part II of this publication. 210 Soil Survey
36B—Varney-Con loams, 36C—Varney-Con loams, 0 to 4 percent slopes 4 to 8 percent slopes
Setting Setting Landform: Landform: • Varney—Alluvial fans and stream terraces • Varney—Alluvial fans and stream terraces • Con—Alluvial fans and stream terraces • Con—Alluvial fans and stream terraces Slope: Slope: • Varney—0 to 4 percent • Varney—4 to 8 percent • Con—0 to 4 percent • Con—4 to 8 percent Elevation: 4,000 to 5,000 feet Elevation: 4,000 to 5,000 feet Mean annual precipitation: 10 to 14 inches Mean annual precipitation: 10 to 14 inches Frost-free period: 90 to 105 days Frost-free period: 90 to 105 days Composition Composition Major Components Major Components Varney and similar soils: 60 percent Varney and similar soils: 60 percent Con and similar soils: 25 percent Con and similar soils: 25 percent Minor Components Minor Components Soils that are clayey throughout: 0 to 10 percent Soils that are clayey throughout: 0 to 10 percent Soils that are cobbly loam throughout: 0 to 5 percent Soils that are very gravelly below 20 inches: 0 to 5 percent Major Component Description Major Component Description Varney Varney Surface layer texture: Loam Surface layer texture: Loam Depth class: Very deep (more than 60 inches) Depth class: Very deep (more than 60 inches) Drainage class: Well drained Drainage class: Well drained Dominant parent material: Alluvium Dominant parent material: Alluvium Native plant cover type: Rangeland Native plant cover type: Rangeland Flooding: None Flooding: None Available water capacity: Mainly 6.8 inches Available water capacity: Mainly 6.9 inches
Con Con Surface layer texture: Loam Surface layer texture: Loam Depth class: Very deep (more than 60 inches) Depth class: Very deep (more than 60 inches) Drainage class: Well drained Drainage class: Well drained Dominant parent material: Alluvium Dominant parent material: Alluvium Native plant cover type: Rangeland Native plant cover type: Rangeland Flooding: None Flooding: None Available water capacity: Mainly 8.8 inches Available water capacity: Mainly 8.8 inches
A typical soil description with range in A typical soil description with range in characteristics is included, in alphabetical order, in characteristics is included, in alphabetical order, in this section. this section. Management Management For management information about this map unit, For management information about this map unit, see appropriate sections in Part II of this publication. see appropriate sections in Part II of this publication. Powell County Area, Montana—Part I 211
36D—Varney-Con loams, 131E—Varney cobbly clay loam, 8 to 15 percent slopes 15 to 35 percent slopes
Setting Setting Landform: Landform: Alluvial fans • Varney—Alluvial fans and stream terraces Slope: 15 to 35 percent • Con—Alluvial fans and stream terraces Elevation: 4,000 to 5,200 feet Slope: Mean annual precipitation: 10 to 14 inches • Varney—8 to 15 percent Frost-free period: 90 to 105 days • Con—8 to 15 percent Composition Elevation: 4,000 to 5,000 feet Mean annual precipitation: 10 to 14 inches Major Components Frost-free period: 90 to 105 days Varney and similar soils: 85 percent Composition Minor Components Anaconda soils: 0 to 8 percent Major Components Sixbeacon cobbly loam: 0 to 7 percent Varney and similar soils: 60 percent Con and similar soils: 25 percent Major Component Description Minor Components Surface layer texture: Cobbly clay loam Soils that are clayey throughout: 0 to 10 percent Depth class: Very deep (more than 60 inches) Con cobbly loam: 0 to 5 percent Drainage class: Well drained Dominant parent material: Alluvium Major Component Description Native plant cover type: Rangeland Flooding: None Varney Available water capacity: Mainly 6.5 inches Surface layer texture: Loam Depth class: Very deep (more than 60 inches) A typical soil description with range in Drainage class: Well drained characteristics is included, in alphabetical order, Dominant parent material: Alluvium in this section. Native plant cover type: Rangeland Management Flooding: None Available water capacity: Mainly 6.8 inches For management information about this map unit, see appropriate sections in Part II of this publication. Con Surface layer texture: Loam Depth class: Very deep (more than 60 inches) 131F—Varney cobbly clay loam, Drainage class: Well drained 35 to 50 percent slopes Dominant parent material: Alluvium Native plant cover type: Rangeland Setting Flooding: None Available water capacity: Mainly 8.8 inches Landform: Alluvial fans Slope: 35 to 50 percent A typical soil description with range in Elevation: 4,000 to 5,200 feet characteristics is included, in alphabetical order, in Mean annual precipitation: 10 to 14 inches this section. Frost-free period: 90 to 105 days Management Composition For management information about this map unit, Major Components see appropriate sections in Part II of this publication. Varney and similar soils: 85 percent 212 Soil Survey
Minor Components Con Anaconda soils: 0 to 8 percent Surface layer texture: Loam Sixbeacon cobbly loam: 0 to 7 percent Depth class: Very deep (more than 60 inches) Drainage class: Well drained Major Component Description Dominant parent material: Alluvium Surface layer texture: Cobbly clay loam Native plant cover type: Rangeland Depth class: Very deep (more than 60 inches) Flooding: None Drainage class: Well drained Available water capacity: Mainly 8.8 inches Dominant parent material: Alluvium Native plant cover type: Rangeland A typical soil description with range in Flooding: None characteristics is included, in alphabetical order, in Available water capacity: Mainly 6.5 inches this section. Management A typical soil description with range in characteristics is included, in alphabetical order, in For management information about this map unit, this section. see appropriate sections in Part II of this publication. Management For management information about this map unit, 236B—Varney sandy clay loam, see appropriate sections in Part II of this publication. 2 to 4 percent slopes
Setting 136E—Varney-Con complex, Landform: Alluvial fans and stream terraces 15 to 35 percent slopes Slope: 2 to 4 percent Elevation: 4,000 to 5,200 feet Mean annual precipitation: 10 to 14 inches Setting Frost-free period: 90 to 105 days Landform: Composition • Varney—Alluvial fans • Con—Alluvial fans and stream terraces Major Components Slope: Varney and similar soils: 85 percent • Varney—15 to 35 percent Minor Components • Con—15 to 35 percent Anaconda soils: 0 to 4 percent Elevation: 4,000 to 5,800 feet Sixbeacon soils: 0 to 4 percent Mean annual precipitation: 10 to 14 inches Soils that have slopes more than 4 percent: 0 to Frost-free period: 90 to 105 days 4 percent Composition Cetrack soils: 0 to 3 percent Major Components Major Component Description Varney and similar soils: 60 percent Surface layer texture: Sandy clay loam Con and similar soils: 25 percent Depth class: Very deep (more than 60 inches) Minor Components Drainage class: Well drained Soils that are clayey throughout: 0 to 8 percent Dominant parent material: Alluvium Sixbeacon soils: 0 to 7 percent Native plant cover type: Rangeland Flooding: None Major Component Description Available water capacity: Mainly 7.3 inches Varney Surface layer texture: Cobbly clay loam A typical soil description with range in Depth class: Very deep (more than 60 inches) characteristics is included, in alphabetical order, in Drainage class: Well drained this section. Dominant parent material: Alluvium Management Native plant cover type: Rangeland Flooding: None For management information about this map unit, Available water capacity: Mainly 6.5 inches see appropriate sections in Part II of this publication. Powell County Area, Montana—Part I 213
236C—Varney sandy clay loam, Minor Components 4 to 8 percent slopes Anaconda soils: 0 to 4 percent Sixbeacon soils: 0 to 4 percent Soils that have slopes more than 15 percent: 0 to Setting 4 percent Landform: Alluvial fans and stream terraces Cetrack soils: 0 to 3 percent Slope: 4 to 8 percent Major Component Description Elevation: 4,000 to 5,200 feet Mean annual precipitation: 10 to 14 inches Surface layer texture: Sandy clay loam Frost-free period: 90 to 105 days Depth class: Very deep (more than 60 inches) Drainage class: Well drained Composition Dominant parent material: Alluvium Major Components Flooding: None Varney and similar soils: 85 percent Available water capacity: Mainly 7.3 inches A typical soil description with range in Minor Components characteristics is included, in alphabetical order, in Anaconda soils: 0 to 4 percent this section. Sixbeacon soils: 0 to 4 percent Soils that have slopes more than 8 percent: 0 to Management 4 percent For management information about this map unit, Cetrack soils: 0 to 3 percent see appropriate sections in Part II of this publication. Major Component Description Surface layer texture: Sandy clay loam Depth class: Very deep (more than 60 inches) 331B—Varney clay loam, 0 to 4 percent Drainage class: Well drained slope, impacted Dominant parent material: Alluvium Native plant cover type: Rangeland Setting Flooding: None Available water capacity: Mainly 7.3 inches Landform: Alluvial fans and stream terraces Slope: 0 to 4 percent A typical soil description with range in Elevation: 4,000 to 5,200 feet characteristics is included, in alphabetical order, in Mean annual precipitation: 10 to 14 inches this section. Frost-free period: 90 to 105 days Management Composition For management information about this map unit, Major Components see appropriate sections in Part II of this publication. Varney and similar soils: 85 percent Minor Components 236D—Varney sandy clay loam, Sixbeacon soils: 0 to 8 percent 8 to 15 percent slopes Beaverell soils: 0 to 7 percent Major Component Description Setting Surface layer texture: Clay loam Landform: Alluvial fans Depth class: Very deep (more than 60 inches) Slope: 8 to 15 percent Drainage class: Well drained Elevation: 4,000 to 5,200 feet Dominant parent material: Alluvium Mean annual precipitation: 10 to 14 inches Flooding: None Frost-free period: 90 to 105 days Available water capacity: Mainly 6.8 inches Composition A typical soil description with range in Major Components characteristics is included, in alphabetical order, in Varney and similar soils: 85 percent this section. 214 Soil Survey
Management Management For management information about this map unit, For management information about this map unit, see appropriate sections in Part II of this publication. see appropriate sections in Part II of this publication.
336B—Varney-Anaconda loams, 336C—Varney-Anaconda loams, 0 to 4 percent slopes, impacted 4 to 8 percent slopes, impacted Setting Setting Landform: Landform: • Varney—Alluvial fans and stream terraces • Varney—Alluvial fans and stream terraces • Anaconda—Alluvial fans and stream terraces • Anaconda—Alluvial fans and stream terraces Slope: Slope: • Varney—4 to 8 percent • Varney—0 to 4 percent • Anaconda—4 to 8 percent • Anaconda—0 to 4 percent Elevation: 4,000 to 5,000 feet Elevation: 4,000 to 5,000 feet Mean annual precipitation: 10 to 14 inches Mean annual precipitation: 10 to 14 inches Frost-free period: 90 to 105 days Frost-free period: 90 to 105 days Composition Composition Major Components Major Components Varney and similar soils: 60 percent Varney and similar soils: 60 percent Anaconda and similar soils: 25 percent Anaconda and similar soils: 25 percent Minor Components Minor Components Soils that are clayey throughout: 0 to 8 percent Soils that are clayey throughout: 0 to 8 percent Soils that have a very gravelly loam subsoil: 0 to Varney cobbly loam: 0 to 7 percent 7 percent Major Component Description Major Component Description Varney Varney Surface layer texture: Loam Surface layer texture: Loam Depth class: Very deep (more than 60 inches) Depth class: Very deep (more than 60 inches) Drainage class: Well drained Drainage class: Well drained Dominant parent material: Alluvium Dominant parent material: Alluvium Flooding: None Flooding: None Available water capacity: Mainly 6.9 inches Available water capacity: Mainly 6.9 inches
Anaconda Anaconda Surface layer texture: Loam Surface layer texture: Loam Depth class: Very deep (more than 60 inches) Depth class: Very deep (more than 60 inches) Drainage class: Well drained Drainage class: Well drained Dominant parent material: Alluvium Dominant parent material: Alluvium Flooding: None Flooding: None Salt affected: Saline within 30 inches Salt affected: Saline within 30 inches Available water capacity: Mainly 7.2 inches Available water capacity: Mainly 7.2 inches
A typical soil description with range in A typical soil description with range in characteristics is included, in alphabetical order, in characteristics is included, in alphabetical order, in this section. this section. Powell County Area, Montana—Part I 215
Management C1—13 to 18 inches; light gray (10YR 7/2) sandy loam, grayish brown (10YR 5/2) moist; common For management information about this map unit, fine prominent reddish yellow (5YR 6/6) redox see appropriate sections in Part II of this publication. concentrations; massive; soft, very friable, slightly sticky, slightly plastic; many very fine and fine and W—Water common medium roots; many fine irregular pores; 15 percent pebbles; violently effervescent; moderately alkaline; clear smooth boundary. Composition 2C2—18 to 60 inches; white (10YR 8/2) very gravelly Major Components coarse sand, light gray (10YR 7/2) moist; Water: 100 percent massive; loose, nonsticky, nonplastic; common fine and medium roots; many fine irregular pores; Major Component Description 15 percent cobbles and 30 percent pebbles; violently effervescent; moderately alkaline. Definition: Areas of open water Range in Characteristics Wetsand Series Soil temperature: 42 to 47 degrees F Moisture control section: Between depths of 4 and Depth class: Very deep 12 inches Drainage class: Poorly drained Depth to the seasonal water table: 12 to 24 inches Permeability: Moderate to the 2C horizon, rapid below A horizon Landform: Flood plains Value: 3 or 4 moist; 4 to 6 dry Parent material: Alluvium Chroma: 1 to 3 Slope range: 0 to 2 percent Clay content: 10 to 25 percent Elevation range: 4,200 to 6,000 feet Content of rock fragments: 0 to 15 percent Annual precipitation: 10 to 19 inches pebbles Annual air temperature: 40 to 44 degrees F Electrical conductivity: 2 to 8 mmhos/cm Frost-free period: 70 to 105 days Reaction: pH 7.4 to 9.0 Taxonomic Class: Fine-loamy over sandy or sandy- AC horizon skeletal, mixed, superactive, calcareous, frigid Value: 5 or 6 dry Aeric Fluvaquents Chroma: 2 or 3 Texture: Loam, silt loam, or sandy loam Typical Pedon Clay content: 5 to 20 percent Wetsand loam, in an area of Carten-Wetsand Content of rock fragments: 0 to 25 percent complex, 0 to 2 percent slopes, rarely flooded, in an pebbles area of pasture, 1,200 feet south and 2,850 feet east Electrical conductivity: 2 to 8 mmhos/cm of the northwest corner of sec. 2, T. 7 N., R. 10 W. Reaction: pH 7.4 to 8.4 C1 horizon Oe—3 inches to 0; decomposed organic matter. Value: 4 or 5 moist; 5 to 7 dry A—0 to 6 inches; gray (10YR 6/1) loam, very dark Chroma: 2 or 3 gray (10YR 3/1) moist; moderate fine granular Redox features: Common or many; distinct or structure; soft, very friable, slightly sticky, slightly prominent; 2.5YR 4/4, 5YR 6/6, or 5YR 6/4 plastic; many very fine, fine, and medium roots; Clay content: 5 to 20 percent many fine irregular pores; 5 percent pebbles; Content of rock fragments: 0 to 35 percent—0 to moderately alkaline; clear smooth boundary. 10 percent cobbles; 0 to 25 percent pebbles AC—6 to 13 inches; light brownish gray (10YR 6/2) Electrical conductivity: 0 to 4 mmhos/cm gravelly sandy loam, very dark grayish brown Reaction: pH 7.4 to 8.4 (10YR 3/2) moist; moderate fine subangular blocky structure; soft, very friable, slightly sticky, 2C2 horizon slightly plastic; many very fine, fine, and medium Value: 4, 5, or 7 moist; 5, 7, or 8 dry roots; many fine irregular pores; 20 percent Chroma: 2 or 3 pebbles; slightly effervescent; moderately Texture: Loamy sand, sand, or coarse sand alkaline; clear wavy boundary. Clay content: 0 to 10 percent 216 Soil Survey
Content of rock fragments: 35 to 80 percent—5 to fragments; strongly effervescent; moderately 20 percent cobbles; 30 to 60 percent pebbles alkaline; gradual wavy boundary. Electrical conductivity: 0 to 4 mmhos/cm Bk3—18 to 26 inches; light yellowish brown (10YR Reaction: pH 7.4 to 8.4 6/4) very gravelly loam, yellowish brown (10YR 5/4) moist; weak medium subangular blocky structure; slightly hard, very friable, slightly sticky, Whitecow Series slightly plastic; common very fine, fine, and medium roots; few fine irregular pores; 10 percent Depth class: Very deep cobbles and 35 percent pebbles; common distinct Drainage class: Well drained lime casts on all sides of coarse fragments; Permeability: Moderate disseminated lime; strongly effervescent; Landform: Mountains moderately alkaline; gradual wavy boundary. Parent material: Colluvium derived from limestone Bk4—26 to 60 inches; pale brown (10YR 6/3) Slope range: 15 to 80 percent extremely cobbly loam, yellowish brown (10YR Elevation range: 4,400 to 6,200 feet 5/4) moist; weak fine subangular blocky structure; Annual precipitation: 18 to 25 inches slightly hard, friable, nonsticky, nonplastic; Annual air temperature: 38 to 42 degrees F few very fine, fine, and medium roots; few Frost-free period: 70 to 90 days fine irregular pores; 30 percent cobbles and 40 percent pebbles; many prominent lime casts Taxonomic Class: Loamy-skeletal, carbonatic, frigid on all sides of coarse fragments; disseminated Typic Calciustepts lime; violently effervescent; moderately alkaline. Typical Pedon Range in Characteristic Whitecow gravelly loam, dry, 15 to 35 percent slopes, in an area of woodland, 2,200 feet north Soil temperature: 38 to 42 degrees F and 2,300 feet east of the southwest corner of Moisture control section: Between depths of 4 and sec. 25, T. 10 N., R. 7 W. 12 inches Oi—1 inch to 0; partially decomposed forest litter. A horizon A—0 to 2 inches; brown (10YR 5/3) gravelly loam, Value: 4 or 5 dry; 3 or 4 moist dark brown (10YR 4/3) moist; weak fine Chroma: 2 or 3 subangular blocky structure; soft, very friable, Clay content: 18 to 27 percent nonsticky, slightly plastic; many very fine and fine Content of rock fragments: 15 to 35 percent—0 to roots; few fine irregular pores; 5 percent cobbles 10 percent cobbles; 15 to 25 percent pebbles and 25 percent pebbles; slightly effervescent; Calcium carbonate equivalent: 5 to 45 percent slightly alkaline; clear wavy boundary. Reaction: pH 7.4 to 8.4 Bk1—2 to 8 inches; brown (10YR 5/3) very gravelly Bk1 and Bk2 horizons loam, dark yellowish brown (10YR 4/4) moist; Hue: 10YR or 2.5Y moderate fine subangular blocky structure; Value: 5 or 6 dry; 4 or 5 moist slightly hard, very friable, slightly sticky, slightly Chroma: 2 to 4 plastic; many very fine and fine and few medium Texture: Loam or clay loam roots; few fine irregular pores; 5 percent cobbles Clay content: 18 to 35 percent and 35 percent pebbles; few faint lime casts on Content of rock fragments: 35 to 70 percent—0 to bottom of coarse fragments; strongly 30 percent stones and cobbles; 5 to 60 percent effervescent; slightly alkaline; clear wavy pebbles or channers boundary. Calcium carbonate equivalent: 40 to 50 percent Bk2—8 to 18 inches; yellowish brown (10YR 5/4) very Reaction: pH 7.4 to 9.0 gravelly loam, dark yellowish brown (10YR 4/4) moist; moderate medium subangular blocky Bk3 horizon structure; slightly hard, very friable, slightly sticky, Hue: 10YR or 2.5Y slightly plastic; common very fine and fine and Value: 6 to 8 dry; 4 to 7 moist few medium and coarse roots; few fine irregular Chroma: 2 to 4 pores; 5 percent cobbles and 40 percent pebbles; Texture: Loam, sandy loam, or clay loam few faint lime casts on all sides of coarse Clay content: 18 to 35 percent Powell County Area, Montana—Part I 217
Content of rock fragments: 35 to 75 percent— 88F—Whitecow gravelly loam, dry, 10 to 15 percent stones and cobbles; 25 to 35 to 60 percent slopes 60 percent pebbles Calcium carbonate equivalent: 40 to 50 percent Setting Reaction: pH 7.4 to 9.0 Landform: Mountains Bk4 horizon Slope: 35 to 60 percent Hue: 10YR or 2.5Y Elevation: 4,400 to 6,200 feet Value: 6 to 8 dry; 4 to 7 moist Mean annual precipitation: 18 to 25 inches Chroma: 2 to 4 Frost-free period: 70 to 90 days Texture: Loam, sandy loam, or clay loam Clay content: 18 to 35 percent Composition Content of rock fragments: 60 to 90 percent—5 to Major Components 30 percent stones and cobbles; 55 to Whitecow and similar soils: 85 percent 70 percent pebbles or channers Calcium carbonate equivalent: 40 to 50 percent Minor Components Reaction: pH 7.4 to 9.0 Areas of rock outcrop: 0 to 8 percent Soils that are moderately deep: 0 to 7 percent Major Component Description 88E—Whitecow gravelly loam, dry, 15 to 35 percent slopes Surface layer texture: Gravelly loam Depth class: Very deep (more than 60 inches) Drainage class: Well drained Setting Dominant parent material: Limestone colluvium Landform: Mountains Native plant cover type: Forestland Slope: 15 to 35 percent Flooding: None Elevation: 4,400 to 6,200 feet Available water capacity: Mainly 4.6 inches Mean annual precipitation: 18 to 25 inches Frost-free period: 70 to 90 days A typical soil description with range in characteristics is included, in alphabetical order, in Composition this section. Major Components Management Whitecow and similar soils: 85 percent For management information about this map unit, Minor Components see appropriate sections in Part II of this publication. Areas of rock outcrop: 0 to 8 percent Soils that have slopes more than 35 percent: 0 to 7 percent 88G—Whitecow gravelly loam, dry, Major Component Description 60 to 80 percent slopes Surface layer texture: Gravelly loam Setting Depth class: Very deep (more than 60 inches) Drainage class: Well drained Landform: Mountains Dominant parent material: Limestone colluvium Slope: 60 to 80 percent Native plant cover type: Forestland Elevation: 4,400 to 6,200 feet Flooding: None Mean annual precipitation: 18 to 25 inches Available water capacity: Mainly 4.1 inches Frost-free period: 70 to 90 days Composition A typical soil description with range in Major Components characteristics is included, in alphabetical order, in Whitecow and similar soils: 85 percent this section. Minor Components Management Areas of rock outcrop: 0 to 5 percent For management information about this map unit, Soils that have a clayey subsoil: 0 to 5 percent see appropriate sections in Part II of this publication. Very gravelly clayey soils: 0 to 5 percent 218 Soil Survey
Major Component Description 488F—Whitecow gravelly loam, cool, Surface layer texture: Gravelly loam 35 to 60 percent slopes Depth class: Very deep (more than 60 inches) Drainage class: Well drained Setting Dominant parent material: Limestone colluvium Landform: Mountains Native plant cover type: Forestland Slope: 35 to 60 percent Flooding: None Elevation: 4,400 to 6,200 feet Available water capacity: Mainly 4.6 inches Mean annual precipitation: 18 to 25 inches Frost-free period: 70 to 90 days A typical soil description with range in characteristics is included, in alphabetical order, in Composition this section. Major Components Management Whitecow and similar soils: 85 percent For management information about this map unit, Minor Components see appropriate sections in Part II of this publication. Soils that are less than 60-inches deep: 0 to 8 percent 488E—Whitecow gravelly loam, cool, Areas of rock outcrop: 0 to 7 percent 15 to 35 percent slopes Major Component Description Setting Surface layer texture: Gravelly loam Landform: Mountains Depth class: Very deep (more than 60 inches) Slope: 15 to 35 percent Drainage class: Well drained Elevation: 4,400 to 6,200 feet Dominant parent material: Limestone colluvium Mean annual precipitation: 18 to 25 inches Native plant cover type: Forestland Frost-free period: 70 to 90 days Flooding: None Available water capacity: Mainly 4.6 inches Composition Major Components A typical soil description with range in Whitecow and similar soils: 85 percent characteristics is included, in alphabetical order, in this section. Minor Components Soils that are less than 60-inches deep: 0 to Management 8 percent For management information about this map unit, Areas of rock outcrop: 0 to 7 percent see appropriate sections in Part II of this publication. Major Component Description Surface layer texture: Gravelly loam Depth class: Very deep (more than 60 inches) 488G—Whitecow gravelly loam, cool, Drainage class: Well drained 60 to 80 percent slopes Dominant parent material: Limestone colluvium Native plant cover type: Forestland Setting Flooding: None Available water capacity: Mainly 4.6 inches Landform: Mountains Slope: 60 to 80 percent A typical soil description with range in Elevation: 4,000 to 6,200 feet characteristics is included, in alphabetical order, in Mean annual precipitation: 18 to 25 inches this section. Frost-free period: 70 to 90 days Management Composition For management information about this map unit, Major Components see appropriate sections in Part II of this publication. Whitecow and similar soils: 85 percent Powell County Area, Montana—Part I 219
Minor Components Rock outcrop Soils that are less than 60-inches deep: 0 to Definition: Areas of exposed bedrock 8 percent Areas of rock outcrop: 0 to 7 percent A typical soil description with range in characteristics is included, in alphabetical order, in Major Component Description this section. Surface layer texture: Gravelly loam Management Depth class: Very deep (more than 60 inches) Drainage class: Well drained For management information about this map unit, Dominant parent material: Limestone colluvium see appropriate sections in Part II of this publication. Native plant cover type: Forestland Flooding: None Available water capacity: Mainly 4.6 inches 988F—Whitecow-Rock outcrop complex, 35 to 60 percent slopes A typical soil description with range in characteristics is included, in alphabetical order, in this section. Setting Management Landform: • Whitecow—Mountains For management information about this map unit, • Rock outcrop—Mountains see appropriate sections in Part II of this publication. Slope: 35 to 60 percent Elevation: 4,400 to 6,200 feet 788F—Whitecow, cool-Rock outcrop Mean annual precipitation: 18 to 25 inches complex, 35 to 60 percent slopes Frost-free period: 70 to 90 days Composition Setting Major Components Landform: Whitecow and similar soils: 55 percent • Whitecow—Mountains Rock outcrop: 30 percent • Rock outcrop—Mountains Minor Components Slope: 35 to 60 percent Soils that are moderately deep: 0 to 4 percent Elevation: 4,400 to 6,200 feet Yreka soils: 0 to 4 percent Mean annual precipitation: 18 to 25 inches Soils that have slopes more than 60 percent: 0 to Frost-free period: 70 to 90 days 4 percent Composition Very gravelly loamy soils: 0 to 3 percent Major Components Major Component Description Whitecow and similar soils: 65 percent Rock outcrop: 20 percent Whitecow Minor Components Surface layer texture: Gravelly loam Trapps soils: 0 to 5 percent Depth class: Very deep (more than 60 inches) Soils that are shallow to bedrock: 0 to 5 percent Drainage class: Well drained Yreka soils: 0 to 5 percent Dominant parent material: Limestone colluvium Native plant cover type: Forestland Major Component Description Flooding: None Whitecow Available water capacity: Mainly 4.6 inches Surface layer texture: Gravelly loam Depth class: Very deep (more than 60 inches) Rock outcrop Drainage class: Well drained Definition: Areas of exposed bedrock Dominant parent material: Limestone colluvium Native plant cover type: Forestland A typical soil description with range in Flooding: None characteristics is included, in alphabetical order, in Available water capacity: Mainly 4.6 inches this section. 220 Soil Survey
Management Whitlash Series For management information about this map unit, Depth class: Shallow see appropriate sections in Part II of this publication. Drainage class: Well drained Permeability: Moderate 988G—Whitecow-Rock outcrop complex, Landform: Mountains 60 to 80 percent slopes Parent material: Igneous residuum Slope range: 15 to 60 percent Elevation range: 3,800 to 5,000 feet Setting Annual precipitation: 15 to 19 inches Landform: Annual air temperature: 39 to 44 degrees F • Whitecow—Mountains Frost-free period: 70 to 90 days • Rock outcrop—Mountains Slope: 60 to 80 percent Taxonomic Class: Loamy-skeletal, mixed, Elevation: 4,400 to 6,200 feet superactive, frigid Lithic Haplustolls Mean annual precipitation: 18 to 25 inches Frost-free period: 70 to 90 days Typical Pedon Composition Whitlash very stony loam, in an area of Perma- Major Components Whitlash-Rock outcrop complex, 35 to 60 percent Whitecow and similar soils: 55 percent slopes, in an area of rangeland, 1,600 feet south and Rock outcrop: 30 percent 1,600 feet east of the northwest corner of sec. 11, T. 10 N., R. 7 W. Minor Components Soils that are moderately deep: 0 to 4 percent A—0 to 5 inches; dark brown (10YR 4/3) very stony Yreka soils: 0 to 4 percent loam, very dark gray (10YR 3/1) moist; weak Soils that have slopes more than 80 percent: 0 to medium subangular blocky structure parting to 4 percent weak fine granular structure; soft, friable, slightly Very gravelly loamy soils: 0 to 3 percent sticky, slightly plastic; many very fine and fine and common medium roots; many very fine interstitial Major Component Description pores; 15 percent stones, 10 percent cobbles, Whitecow and 20 percent pebbles; slightly acid; clear Surface layer texture: Gravelly loam smooth boundary. Depth class: Very deep (more than 60 inches) Bw—5 to 17 inches; dark grayish brown (10YR 4/2) Drainage class: Well drained very cobbly loam, very dark grayish brown (10YR Dominant parent material: Limestone colluvium 3/2) moist; weak fine subangular blocky structure; Native plant cover type: Forestland slightly hard, friable, slightly sticky, slightly plastic; Flooding: None many very fine, fine, and medium roots; many Available water capacity: Mainly 4.6 inches very fine interstitial pores; 10 percent stones, 30 percent cobbles, and 15 percent pebbles; Rock outcrop neutral. Definition: Areas of exposed bedrock R—17 inches; igneous bedrock.
A typical soil description with range in Range in Characteristics characteristics is included, in alphabetical order, in this section. Soil temperature: 41 to 47 degrees F Moisture control section: Between depths of 4 and Management 12 inches; and moist in all parts April, May, and For management information about this map unit, June see appropriate sections in Part II of this publication. Depth to bedrock: 10 to 20 inches Powell County Area, Montana—Part I 221
A horizon Bw—2 to 8 inches; brown (10YR 5/3) gravelly loam, Value: 3 or 4 dry; 2 or 3 moist brown (10YR 4/3) moist; moderate medium Chroma: 1 to 3 subangular blocky structure; slightly hard, friable, Clay content: 18 to 27 percent, with less than moderately sticky and moderately plastic; 35 percent fine and coarser sand common very fine, fine, medium, and coarse Content of rock fragments: 35 to 60 percent— roots; common very fine and fine irregular pores; 10 to 30 percent stones, flagstones, and 10 percent cobbles and 20 percent pebbles; cobbles; 15 to 35 percent pebbles or channers violently effervescent; slightly alkaline; clear Reaction: pH 6.1 to 7.3 smooth boundary. Bk1—8 to 20 inches; very pale brown (10YR 7/3) very Bw horizon gravelly loam, brown (10YR 5/3) moist; moderate Value: 4 or 5 dry; 3 or 4 moist fine subangular blocky structure; slightly hard, Chroma: 2 or 3 very friable, slightly sticky, slightly plastic; Texture: Loam, sandy clay loam, or sandy loam common very fine and fine and few medium and Clay content: 18 to 27 percent, with less than coarse roots; common very fine irregular pores; 35 percent fine and coarser sand 15 percent cobbles and 35 percent pebbles; Content of rock fragments: 35 to 80 percent—5 to disseminated lime; violently effervescent; 50 percent stones, flagstones and cobbles; moderately alkaline; gradual wavy boundary. 15 to 60 percent pebbles or channers Bk2—20 to 60 inches; light gray (10YR 7/2) extremely Reaction: pH 6.6 to 7.3 cobbly loam, yellowish brown (10YR 5/4) moist; weak fine subangular blocky structure; slightly Whitore Series hard, very friable, slightly sticky, slightly plastic; few very fine and fine roots; common very Depth class: Very deep fine irregular pores; 30 percent cobbles and Drainage class: Well drained 35 percent pebbles; disseminated lime; violently Permeability: Moderate effervescent; moderately alkaline. Landform: Mountains Parent material: Colluvium derived from limestone Range in Characteristics Slope range: 15 to 60 percent Elevation range: 5,200 to 7,200 feet Soil temperature: 38 to 42 degrees F Annual precipitation: 20 to 26 inches Moisture control section: Between depths of 4 and Annual air temperature: 35 to 38 degrees F 12 inches Frost-free period: 30 to 70 days Depth to the Bk horizon: 5 to 15 inches
Taxonomic Class: Loamy-skeletal, carbonatic Typic A horizon Eutrocryepts Value: 4 to 6 dry; 3 or 4 moist Chroma: 1 to 3 Typical Pedon Clay content: 20 to 27 percent Whitore gravelly loam, 35 to 60 percent slopes, in an Content of rock fragments: 15 to 35 percent—0 to area of woodland, 2,000 feet north and 1,200 feet 5 percent cobbles; 15 to 30 percent pebbles west of the southeast corner of sec. 5, T. 11 N., Reaction: pH 6.6 to 7.8 R. 11 W. Bw horizon Oi—2 inches to 0; partially decomposed needles and Value: 5 or 6 dry; 4 or 5 moist twigs. Chroma: 2 to 4 A—0 to 2 inches; dark grayish brown (10YR 4/2) Texture: Clay loam or loam gravelly loam, very dark gray (10YR 3/1) moist; Clay content: 20 to 27 percent weak fine granular structure; soft, friable, slightly Content of rock fragments: 15 to 60 percent— sticky, slightly plastic; many very fine, fine, 10 to 25 percent stones and cobbles; 5 to medium, and coarse roots; many very fine and 35 percent pebbles or channers fine irregular pores; 5 percent cobbles and Effervescence: Slightly to violently in the lower 20 percent pebbles; strongly effervescent; neutral; half clear smooth boundary. Reaction: pH 7.4 to 9.0 222 Soil Survey
Bk horizons 92F—Whitore gravelly loam, Hue: 10YR or 2.5Y 35 to 60 percent slopes Value: 6 to 8 dry; 4 to 7 moist Chroma: 2 to 4 Setting Texture: Clay loam or loam Clay content: 20 to 35 percent Landform: Mountains Content of rock fragments: 35 to 85 percent—0 to Slope: 35 to 60 percent 40 percent stones and cobbles; 25 to 45 Elevation: 5,200 to 7,200 feet percent pebbles or channers Mean annual precipitation: 20 to 26 inches Calcium carbonate equivalent: 40 to 50 percent Frost-free period: 30 to 70 days Reaction: pH 7.4 to 9.0 Composition Major Components 92E—Whitore gravelly loam, Whitore and similar soils: 85 percent 15 to 35 percent slopes Minor Components Areas of rock outcrop: 0 to 8 percent Setting Soils that are 10 to 60 inches to rock: 0 to 7 percent Landform: Mountains Major Component Description Slope: 15 to 35 percent Elevation: 5,200 to 7,200 feet Surface layer texture: Gravelly loam Mean annual precipitation: 20 to 26 inches Depth class: Very deep (more than 60 inches) Frost-free period: 30 to 70 days Drainage class: Well drained Dominant parent material: Limestone colluvium Composition Native plant cover type: Forestland Major Components Flooding: None Whitore and similar soils: 85 percent Available water capacity: Mainly 4.6 inches Minor Components A typical soil description with range in Areas of rock outcrop: 0 to 8 percent characteristics is included, in alphabetical order, in Soils that have slopes more than 35 percent: 0 to this section. 7 percent Management Major Component Description For management information about this map unit, Surface layer texture: Gravelly loam see appropriate sections in Part II of this publication. Depth class: Very deep (more than 60 inches) Drainage class: Well drained Dominant parent material: Limestone colluvium Wildgen Series Native plant cover type: Forestland Flooding: None Depth class: Very deep Available water capacity: Mainly 4.6 inches Drainage class: Well drained Permeability: Moderate A typical soil description with range in Landform: Moraines characteristics is included, in alphabetical order, in Parent material: Alpine till this section. Slope range: 2 to 50 percent Elevation range: 4,000 to 5,000 feet Management Annual precipitation: 18 to 24 inches For management information about this map unit, Annual air temperature: 38 to 42 degrees F see appropriate sections in Part II of this publication. Frost-free period: 70 to 90 days Powell County Area, Montana—Part I 223
Taxonomic Class: Loamy-skeletal, mixed, Texture: Loam or sandy loam superactive, frigid Lamellic Haplustepts Clay content: 15 to 25 percent Content of rock fragments: 35 to 60 percent—0 to Typical Pedon 20 percent stones and cobbles; 30 to Wildgen gravelly loam, in an area of Wildgen-Yreka 40 percent pebbles gravelly loams, 8 to 25 percent slopes, in an area of Reaction: pH 6.1 to 7.3 woodland, 400 feet north and 2,350 feet west of the E and Bt horizon southeast corner of sec. 15, T. 15 N., R. 12 W. Hue: E part—10YR or 7.5YR; B part—10YR or Oi—2 inches to 0; undecomposed and slightly 7.5YR decomposed forest litter. Value: E part—6 to 8 dry, 5 to 7 moist; B part 4 to E1—0 to 8 inches; pale brown (10YR 6/3) gravelly 7 dry, 3 to 5 moist loam, dark yellowish brown (10YR 4/4) moist; Chroma: E part—1 to 4; B part—3, 4, or 6 moderate medium granular structure; slightly Texture: Loam or sandy loam hard, friable, slightly sticky, slightly plastic; many Clay content: 10 to 25 percent; lamellae have less very fine, fine, medium, and coarse roots; many than 3 percent increase in clay fine pores; 20 percent pebbles; slightly acid; clear Content of rock fragments: 40 to 60 percent—0 to smooth boundary. 20 percent stones and cobbles; 35 to E2—8 to 15 inches; light brown (7.5YR 6/4) very 40 percent pebbles gravelly loam, brown (7.5YR 4/4) moist; weak Reaction: pH 6.1 to 7.3 medium subangular blocky structure parting to moderate medium granular structure; slightly hard, friable, slightly sticky, moderately plastic; 371C—Wildgen-Yreka gravelly loams, many very fine, fine, medium, and coarse roots; 2 to 8 percent slopes many fine pores; 40 percent pebbles; slightly acid; gradual wavy boundary. Setting E and Bt—15 to 60 inches; 75 percent is pink (7.5YR Landform: 7/4) very cobbly loam, brown (7.5YR 5/4) moist • Wildgen—Moraines (E part); 25 percent is strong brown (7.5YR 4/6) 1 3 • Yreka—Moraines very cobbly loam lamellae /4- to /8-inch thick, Slope: dark brown (7.5YR 4/4) moist (B part); weak • Wildgen—2 to 8 percent medium subangular blocky structure; slightly • Yreka—2 to 8 percent hard, friable, slightly sticky, moderately plastic; Elevation: 4,000 to 5,000 feet common very fine, fine, and medium roots; Mean annual precipitation: 18 to 24 inches common fine pores; 5 percent stones, 15 percent Frost-free period: 70 to 90 days cobbles, and 35 percent pebbles; slightly acid. Composition Range in Characteristics Major Components Soil temperature: 40 to 47 degrees F Wildgen and similar soils: 55 percent Moisture control section: Between depths of 4 and Yreka and similar soils: 30 percent 12 inches Minor Components E1 horizon Poorly drained soils: 0 to 4 percent Hue: 10YR or 7.5YR Soils that have a thick volcanic ash surface: 0 to Value: 6 or 7 dry; 3 or 4 moist 4 percent Chroma: 2 to 4 Very gravelly sandy soils: 0 to 3 percent Clay content: 15 to 25 percent Soils that have slopes more than 8 percent: 0 to Content of rock fragments: 15 to 35 percent—0 to 4 percent 10 percent stones and cobbles; 15 to 25 percent pebbles Major Component Description Reaction: pH 6.1 to 7.3 Wildgen E2 horizon Surface layer texture: Gravelly loam Hue: 10YR or 7.5YR Depth class: Very deep (more than 60 inches) Value: 6 to 8 dry; 4 to 7 moist Drainage class: Well drained Chroma: 1 to 4 Dominant parent material: Alpine till 224 Soil Survey
Native plant cover type: Forestland Native plant cover type: Forestland Flooding: None Flooding: None Available water capacity: Mainly 5.2 inches Available water capacity: Mainly 5.2 inches
Yreka Yreka Surface layer texture: Gravelly loam Surface layer texture: Gravelly loam Depth class: Very deep (more than 60 inches) Depth class: Very deep (more than 60 inches) Drainage class: Well drained Drainage class: Well drained Dominant parent material: Alpine till Dominant parent material: Alpine till Flooding: None Native plant cover type: Forestland Available water capacity: Mainly 5.6 inches Flooding: None Available water capacity: Mainly 5.6 inches A typical soil description with range in characteristics is included, in alphabetical order, in A typical soil description with range in this section. characteristics is included, in alphabetical order, in this section. Management Management For management information about this map unit, see appropriate sections in Part II of this publication. For management information about this map unit, see appropriate sections in Part II of this publication. 371E—Wildgen-Yreka gravelly loams, 8 to 25 percent slopes 371F—Wildgen-Yreka gravelly loams, 25 to 50 percent slopes Setting Setting Landform: • Wildgen—Moraines Landform: • Yreka—Moraines • Wildgen—Moraines Slope: • Yreka—Moraines • Wildgen—8 to 25 percent Slope: • Yreka—8 to 25 percent • Wildgen—25 to 50 percent Elevation: 4,000 to 5,000 feet • Yreka—25 to 50 percent Mean annual precipitation: 18 to 24 inches Elevation: 4,000 to 5,000 feet Frost-free period: 70 to 90 days Mean annual precipitation: 18 to 24 inches Frost-free period: 70 to 90 days Composition Composition Major Components Wildgen and similar soils: 55 percent Major Components Yreka and similar soils: 30 percent Wildgen and similar soils: 55 percent Yreka and similar soils: 30 percent Minor Components Poorly drained soils: 0 to 4 percent Minor Components Soils that have a thick volcanic ash surface: 0 to Poorly drained soils: 0 to 4 percent 4 percent Soils that have a thick volcanic ash surface: 0 to Very gravelly sandy soils: 0 to 3 percent 4 percent Soils that have slopes more than 25 percent: 0 to Very gravelly sandy soils: 0 to 3 percent 4 percent Soils that have slopes more than 50 percent: 0 to 4 percent Major Component Description Major Component Description Wildgen Surface layer texture: Gravelly loam Wildgen Depth class: Very deep (more than 60 inches) Surface layer texture: Gravelly loam Drainage class: Well drained Depth class: Very deep (more than 60 inches) Dominant parent material: Alpine till Drainage class: Well drained Powell County Area, Montana—Part I 225
Dominant parent material: Alpine till Bk1—9 to 16 inches; dark brown (10YR 4/3) very Native plant cover type: Forestland gravelly loam, dark brown (10YR 3/3) moist; Flooding: None weak fine and medium subangular blocky Available water capacity: Mainly 5.2 inches structure; soft, very friable, nonsticky, nonplastic; common very fine and few fine and medium Yreka roots; many very fine and fine discontinuous Surface layer texture: Gravelly loam pores; 10 percent cobbles and 30 percent Depth class: Very deep (more than 60 inches) pebbles; disseminated lime; common distinct lime Drainage class: Well drained casts on bottom of coarse fragments; violently Dominant parent material: Alpine till effervescent; moderately alkaline; gradual wavy Native plant cover type: Forestland boundary. Flooding: None Bk2—16 to 29 inches; brown (10YR 5/3) extremely Available water capacity: Mainly 5.6 inches gravelly loam, dark brown (10YR 4/3) moist; weak fine and medium subangular blocky A typical soil description with range in structure; soft, very friable, nonsticky, nonplastic; characteristics is included, in alphabetical order, in common very fine and few fine and medium this section. roots; many very fine and fine discontinuous pores; 10 percent cobbles and 55 percent Management pebbles; disseminated lime; common distinct lime For management information about this map unit, casts on bottom of coarse fragments; violently see appropriate sections in Part II of this publication. effervescent; moderately alkaline; gradual wavy boundary. Bk3—29 to 60 inches; pale brown (10YR 6/3) Windham Series extremely gravelly loam, brown (10YR 5/3) moist; weak fine subangular blocky structure; soft, very Depth class: Very deep friable, nonsticky, nonplastic; few very fine, fine, Drainage class: Well drained and medium roots; many very fine and common Permeability: Moderate fine discontinuous pores; 20 percent cobbles and Landform: Mountains 55 percent pebbles; disseminated lime; common Parent material: Colluvium derived from limestone distinct lime casts on bottom of coarse fragments; Slope range: 15 to 60 percent violently effervescent; moderately alkaline. Elevation range: 4,000 to 5,800 feet Range in Characteristics Annual precipitation: 15 to 19 inches Annual air temperature: 39 to 44 degrees F Soil temperature: 41 to 46 degrees F Frost-free period: 70 to 90 days Thickness of the mollic epipedon: 7 to 16 inches Depth to the calcic horizon: 5 to 10 inches Taxonomic Class: Loamy-skeletal, carbonatic, frigid A horizon Typic Calciustolls Hue: 7.5YR or 10YR Value: 4 or 5 dry; 2 or 3 moist Typical Pedon Chroma: 1 to 3 Windham gravelly loam, in an area of Windham-Lap Clay content: 18 to 27 percent gravelly loams, 35 to 60 percent slopes, in an area of Content of rock fragments: 15 to 35 percent—0 to rangeland, 2,150 feet south and 1,600 feet east of the 5 percent cobbles; 15 to 30 percent pebbles northwest corner of sec. 5, T. 9 N., R. 6 W. Calcium carbonate equivalent: 5 to 10 percent Reaction: pH 7.4 to 8.4 A—0 to 9 inches; dark brown (10YR 4/3) gravelly loam, very dark brown (10YR 2/2) moist; weak Bk1 horizon fine granular structure; soft, very friable, Hue: 7.5YR, 10YR, or 2.5Y nonsticky, nonplastic; many very fine and fine, Value: 4 to 6 dry; 3 to 6 moist common medium, and few coarse roots; many Chroma: 2 to 4 very fine and fine discontinuous pores; 5 percent Texture: Loam or clay loam cobbles and 25 percent pebbles; strongly Clay content: 18 to 35 percent effervescent; slightly alkaline; clear wavy Content of rock fragments: 10 to 75 percent—0 to boundary. 20 percent cobbles; 10 to 55 percent pebbles 226 Soil Survey
Calcium carbonate equivalent: 35 to 60 percent A typical soil description with range in Reaction: pH 7.9 to 8.4 characteristics is included, in alphabetical order, in this section. Bk2 horizon Hue: 7.5YR, 10YR, or 2.5Y Management Value: 5 to 8 dry; 4 to 7 moist For management information about this map unit, Chroma: 2 to 4 see appropriate sections in Part II of this publication. Texture: Loam, clay loam, or sandy loam Clay content: 18 to 35 percent Content of rock fragments: 35 to 75 percent—0 to 42F—Windham gravelly loam, 20 percent cobbles; 35 to 55 percent pebbles 35 to 60 percent slopes Calcium carbonate equivalent: 40 to 60 percent Reaction: pH 7.9 to 8.4 Setting Bk3 horizon Landform: Mountains Hue: 7.5YR, 10YR, or 2.5Y Slope: 35 to 60 percent Value: 5 to 8 dry; 4 to 7 moist Elevation: 4,000 to 5,800 feet Chroma: 2 to 4 Mean annual precipitation: 15 to 19 inches Texture: Loam, clay loam, or sandy loam Frost-free period: 70 to 90 days Clay content: 18 to 35 percent Content of rock fragments: 60 to 80 percent—5 to Composition 20 percent cobbles; 55 to 60 percent pebbles Major Components Calcium carbonate equivalent: 40 to 60 percent Windham and similar soils: 85 percent Reaction: pH 7.9 to 8.4 Minor Components Soils that are moderately deep to deep: 0 to 42E—Windham gravelly loam, 10 percent 15 to 35 percent slopes Soils that have slopes more than 60 percent: 0 to 5 percent Major Component Description Setting Surface layer texture: Gravelly loam Landform: Mountains Depth class: Very deep (more than 60 inches) Slope: 15 to 35 percent Drainage class: Well drained Elevation: 4,000 to 5,800 feet Dominant parent material: Limestone colluvium Mean annual precipitation: 15 to 19 inches Native plant cover type: Rangeland Frost-free period: 70 to 90 days Flooding: None Composition Available water capacity: Mainly 3.4 inches Major Components A typical soil description with range in Windham and similar soils: 85 percent characteristics is included, in alphabetical order, in Minor Components this section. Soils that are moderately deep to deep: 0 to Management 10 percent Soils that have slopes more than 35 percent: 0 to For management information about this map unit, 5 percent see appropriate sections in Part II of this publication.
Major Component Description 839E—Windham-Lap gravelly loams, Surface layer texture: Gravelly loam 15 to 35 percent slopes Depth class: Very deep (more than 60 inches) Drainage class: Well drained Setting Dominant parent material: Limestone colluvium Native plant cover type: Rangeland Landform: Flooding: None • Windham—Mountains Available water capacity: Mainly 3.4 inches • Lap—Mountains Powell County Area, Montana—Part I 227
Slope: Slope: • Windham—15 to 35 percent • Windham—35 to 60 percent • Lap—15 to 35 percent • Lap—35 to 60 percent Elevation: 4,000 to 5,800 feet Elevation: 4,000 to 5,800 feet Mean annual precipitation: 15 to 19 inches Mean annual precipitation: 15 to 19 inches Frost-free period: 70 to 90 days Frost-free period: 70 to 90 days Composition Composition Major Components Major Components Windham and similar soils: 65 percent Windham and similar soils: 65 percent Lap and similar soils: 20 percent Lap and similar soils: 20 percent Minor Components Minor Components Areas of rock outcrop: 0 to 8 percent Areas of rock outcrop: 0 to 8 percent Soils that have slopes more than 35 percent: 0 to Soils that have slopes more than 60 percent: 0 to 7 percent 7 percent Major Component Description Major Component Description Windham Windham Surface layer texture: Gravelly loam Surface layer texture: Gravelly loam Depth class: Very deep (more than 60 inches) Depth class: Very deep (more than 60 inches) Drainage class: Well drained Drainage class: Well drained Dominant parent material: Limestone colluvium Dominant parent material: Limestone colluvium Native plant cover type: Rangeland Native plant cover type: Rangeland Flooding: None Flooding: None Available water capacity: Mainly 3.4 inches Available water capacity: Mainly 3.4 inches
Lap Lap Surface layer texture: Gravelly loam Surface layer texture: Gravelly loam Depth class: Shallow (10 to 20 inches) Depth class: Shallow (10 to 20 inches) Drainage class: Well drained Drainage class: Well drained Dominant parent material: Limestone residuum Dominant parent material: Limestone residuum Native plant cover type: Rangeland Native plant cover type: Rangeland Flooding: None Flooding: None Available water capacity: Mainly 1.8 inches Available water capacity: Mainly 1.8 inches
A typical soil description with range in A typical soil description with range in characteristics is included, in alphabetical order, in characteristics is included, in alphabetical order, in this section. this section. Management Management For management information about this map unit, For management information about this map unit, see appropriate sections in Part II of this publication. see appropriate sections in Part II of this publication.
839F—Windham-Lap gravelly loams, Winfall Series 35 to 60 percent slopes Depth class: Very deep Drainage class: Well drained Setting Permeability: Moderate Landform: Moraines Landform: Parent material: Alpine till • Windham—Mountains Slope range: 2 to 50 percent • Lap—Mountains Elevation range: 4,000 to 5,000 feet 228 Soil Survey
Annual precipitation: 20 to 30 inches Texture: Loam, fine sandy loam, sandy loam, or Annual air temperature: 38 to 42 degrees F coarse sandy loam Frost-free period: 70 to 90 days Clay content: 10 to 20 percent; lamellae have less than 3 percent increase in clay Taxonomic Class: Loamy-skeletal, mixed, Content of rock fragments: 35 to 60 percent—0 to superactive, frigid Lamellic Eutrudepts 15 percent cobbles; 35 to 45 percent pebbles Reaction: pH 5.1 to 6.5 Typical Pedon Winfall gravelly loam, 2 to 8 percent slopes, in an area of woodland, 700 feet south and 1,300 feet east 71C—Winfall gravelly loam, of the northwest corner of sec. 11, T. 15 N., R. 12 W. 2 to 8 percent slopes Oe—3 inches to 0; decomposed and slightly Setting decomposed twigs and needles. E—0 to 16 inches; pale brown (10YR 6/3) gravelly Landform: Moraines loam, brown (10YR 4/3) moist; moderate fine Slope: 2 to 8 percent and medium subangular blocky structure; soft, Elevation: 4,000 to 5,000 feet friable, slightly sticky, slightly plastic; many very Mean annual precipitation: 20 to 30 inches fine, fine, and medium and few coarse roots; Frost-free period: 70 to 90 days many fine interstitial pores; 5 percent cobbles Composition and 25 percent pebbles; slightly acid; clear smooth boundary. Major Components E and Bt—16 to 60 inches; 70 percent is light gray Winfall and similar soils: 85 percent (10YR 7/2) very gravelly coarse sandy loam, Minor Components brown (10YR 5/3) moist (E part); 30 percent is Yreka soils: 0 to 6 percent light yellowish brown (10YR 6/4) fine sandy loam 1 3 Soils that have slopes more than 8 percent: 0 to lamellae /8- to /8-inch thick, brown (10YR 4/3) 6 percent moist (B part); texture mixed is very gravelly Poorly drained soils: 0 to 3 percent sandy loam; weak medium subangular blocky structure; soft, friable, slightly sticky, slightly Major Component Description plastic; common very fine and fine roots; few Surface layer texture: Gravelly loam fine interstitial pores; 10 percent cobbles and Depth class: Very deep (more than 60 inches) 45 percent pebbles; slightly acid. Drainage class: Well drained Range in Characteristics Dominant parent material: Alpine till Native plant cover type: Forestland Soil temperature: 42 to 46 degrees F Flooding: None Moisture control section: Between depths of 8 and Available water capacity: Mainly 5.9 inches 24 inches E horizon A typical soil description with range in Hue: 5YR, 7.5YR, or 10YR characteristics is included, in alphabetical order, in Value: 5 to 7 dry; 4 or 5 moist this section. Chroma: 2 to 4 Management Clay content: 10 to 20 percent Content of rock fragments: 35 to 60 percent—0 to For management information about this map unit, 5 percent stones and cobbles; 15 to 30 percent see appropriate sections in Part II of this publication. pebbles Reaction: pH 5.1 to 6.5 71E—Winfall gravelly loam, E and Bt horizon 8 to 25 percent slopes Hue: E part—5YR, 7.5YR, or 10YR; B part—5YR, 7.5YR, or 10YR Setting Value: E part—6 or 7 dry, 5 or 6 moist; B part— 5 or 6 dry, 4 or 5 moist Landform: Moraines Chroma: E part—2 or 3; B part—3 or 4 Slope: 8 to 25 percent Powell County Area, Montana—Part I 229
Elevation: 4,000 to 5,000 feet Native plant cover type: Forestland Mean annual precipitation: 20 to 30 inches Flooding: None Frost-free period: 70 to 90 days Available water capacity: Mainly 5.9 inches Composition A typical soil description with range in Major Components characteristics is included, in alphabetical order, in Winfall and similar soils: 85 percent this section. Minor Components Management Yreka soils: 0 to 10 percent For management information about this map unit, Poorly drained soils: 0 to 5 percent see appropriate sections in Part II of this publication. Major Component Description Surface layer texture: Gravelly loam Depth class: Very deep (more than 60 inches) 171C—Winfall-Rumblecreek gravelly Drainage class: Well drained loams, 2 to 8 percent slopes Dominant parent material: Alpine till Native plant cover type: Forestland Setting Flooding: None Landform: Available water capacity: Mainly 5.9 inches • Winfall—Moraines • Rumblecreek—Moraines A typical soil description with range in Slope: characteristics is included, in alphabetical order, in • Winfall—2 to 8 percent this section. • Rumblecreek—2 to 8 percent Management Elevation: 4,000 to 4,700 feet Mean annual precipitation: 20 to 30 inches For management information about this map unit, Frost-free period: 70 to 90 days see appropriate sections in Part II of this publication. Composition 71F—Winfall gravelly loam, Major Components 25 to 50 percent slopes Winfall and similar soils: 60 percent Rumblecreek and similar soils: 25 percent Setting Minor Components Crow soils: 0 to 5 percent Landform: Moraines Poorly drained soils: 0 to 4 percent Slope: 25 to 50 percent Areas of open water: 0 to 3 percent Elevation: 4,000 to 5,000 feet Soils that have a thick volcanic ash surface: 0 to Mean annual precipitation: 20 to 30 inches 3 percent Frost-free period: 70 to 90 days Major Component Description Composition Winfall Major Components Surface layer texture: Gravelly loam Winfall and similar soils: 85 percent Depth class: Very deep (more than 60 inches) Minor Components Drainage class: Well drained Yreka soils: 0 to 6 percent Dominant parent material: Alpine till Soils that have slopes more than 60 percent: 0 to Native plant cover type: Forestland 6 percent Flooding: None Poorly drained soils: 0 to 3 percent Available water capacity: Mainly 5.9 inches Major Component Description Rumblecreek Surface layer texture: Gravelly loam Surface layer texture: Gravelly loam Depth class: Very deep (more than 60 inches) Depth class: Very deep (more than 60 inches) Drainage class: Well drained Drainage class: Well drained Dominant parent material: Alpine till Dominant parent material: Alpine till 230 Soil Survey
Native plant cover type: Forestland Flooding: None Flooding: None Available water capacity: Mainly 5.2 inches Available water capacity: Mainly 5.2 inches A typical soil description with range in A typical soil description with range in characteristics is included, in alphabetical order, in characteristics is included, in alphabetical order, in this section. this section. Management Management For management information about this map unit, For management information about this map unit, see appropriate sections in Part II of this publication. see appropriate sections in Part II of this publication. 171F—Winfall-Rumblecreek gravelly 171E—Winfall-Rumblecreek gravelly loams, 25 to 50 percent slopes loams, 8 to 25 percent slopes Setting Setting Landform: Landform: • Winfall—Moraines • Winfall—Moraines • Rumblecreek—Moraines • Rumblecreek—Moraines Slope: Slope: • Winfall—25 to 50 percent • Winfall—8 to 25 percent • Rumblecreek—25 to 50 percent • Rumblecreek—8 to 25 percent Elevation: 4,000 to 4,700 feet Elevation: 4,000 to 4,700 feet Mean annual precipitation: 20 to 30 inches Mean annual precipitation: 20 to 30 inches Frost-free period: 70 to 90 days Frost-free period: 70 to 90 days Composition Composition Major Components Major Components Winfall and similar soils: 60 percent Winfall and similar soils: 60 percent Rumblecreek and similar soils: 25 percent Rumblecreek and similar soils: 25 percent Minor Components Minor Components Somewhat poorly drained soils: 0 to 4 percent Poorly drained soils: 0 to 5 percent Soils that have slopes more than 50 percent: 0 to Bignell soils: 0 to 5 percent 4 percent Soils that have a thick volcanic ash surface: 0 to Bignell soils: 0 to 4 percent 5 percent Poorly drained soils: 0 to 3 percent Major Component Description Major Component Description Winfall Winfall Surface layer texture: Gravelly loam Surface layer texture: Gravelly loam Depth class: Very deep (more than 60 inches) Depth class: Very deep (more than 60 inches) Drainage class: Well drained Drainage class: Well drained Dominant parent material: Alpine till Dominant parent material: Alpine till Native plant cover type: Forestland Native plant cover type: Forestland Flooding: None Flooding: None Available water capacity: Mainly 5.9 inches Available water capacity: Mainly 5.9 inches
Rumblecreek Rumblecreek Surface layer texture: Gravelly loam Surface layer texture: Gravelly loam Depth class: Very deep (more than 60 inches) Depth class: Very deep (more than 60 inches) Drainage class: Well drained Drainage class: Well drained Dominant parent material: Alpine till Dominant parent material: Alpine till Native plant cover type: Forestland Native plant cover type: Forestland Powell County Area, Montana—Part I 231
Flooding: None structure; soft, very friable, nonsticky, nonplastic; Available water capacity: Mainly 5.2 inches common very fine and fine roots; many fine pores; 10 percent angular cobbles and A typical soil description with range in 40 percent angular pebbles; moderately acid; characteristics is included, in alphabetical order, in gradual wavy boundary. this section. E and Bt—26 to 41 inches; 75 percent is pinkish white (7.5YR 8/2) extremely gravelly sandy loam, Management brown (7.5YR 5/4) moist (E part); 25 percent is 1 For management information about this map unit, brown (7.5YR 5/4) fine sandy loam lamellae /8- to 1 see appropriate sections in Part II of this publication. /4-inch thick, brown (7.5YR 4/4) moist (B part); weak medium subangular blocky structure; slightly hard, very friable, nonsticky, nonplastic; Winkler Series few fine and medium roots; common very fine and fine pores; 20 percent angular cobbles and Depth class: Very deep 50 percent angular pebbles; moderately acid; Drainage class: Somewhat excessively drained gradual wavy boundary. Permeability: Moderately rapid C—41 to 60 inches; pinkish gray (7.5YR 7/2) Landform: Mountains extremely gravelly sandy loam, brown (7.5YR Parent material: Colluvium derived from argillite and 5/2) moist; massive; soft, very friable, nonsticky, quartzite nonplastic; few fine roots; few fine pores; Slope range: 8 to 80 percent 20 percent angular cobbles and 55 percent Elevation range: 4,400 to 6,500 feet angular pebbles; moderately acid. Annual precipitation: 18 to 24 inches Annual air temperature: 38 to 42 degrees F Range in Characteristics Frost-free period: 70 to 90 days Soil temperature: 42 to 47 degrees F Moisture control section: Between depths of 8 and Taxonomic Class: Loamy-skeletal, mixed, 24 inches superactive, frigid Lamellic Haplustepts A horizon Typical Pedon Hue: 7.5YR or 10YR Value: 3 or 4 moist Winkler gravelly loam, 35 to 60 percent slopes, in an Chroma: 2 or 3 area of woodland, 1,600 feet south and 2,400 feet Clay content: 7 to 15 percent west of the northeast corner of sec. 7, T. 12 N., Content of rock fragments: 15 to 35 percent—0 to R. 9 W. 5 percent angular cobbles; 15 to 30 percent Oi—2 inches to 0; undecomposed and slightly angular pebbles decomposed forest litter. Reaction: pH 6.1 to 7.3 A—0 to 3 inches; grayish brown (10YR 5/2) gravelly E1 horizon loam, very dark grayish brown (10YR 3/2) moist; Hue: 7.5YR or 10YR weak fine granular structure; soft, very friable, Value: 6 to 8 dry; 5 to 7 moist nonsticky, nonplastic; many very fine, fine, Chroma: 2 to 4 medium, and coarse roots; many fine pores; Texture: Sandy loam or loam 30 percent angular pebbles; neutral; clear smooth Clay content: 5 to 15 percent boundary. Content of rock fragments: 15 to 60 percent—0 to E1—3 to 13 inches; very pale brown (10YR 7/3) 5 percent angular cobbles; 15 to 55 percent gravelly sandy loam, brown (10YR 5/3) moist; angular pebbles weak fine and medium granular structure; soft, Reaction: pH 6.1 to 7.3 very friable, nonsticky, nonplastic; many very fine, fine, medium, and coarse roots; many fine pores; E2 horizon 30 percent angular pebbles; moderately acid; Hue: 2.5Y, 10YR, or 7.5YR gradual wavy boundary. Value: 6 to 8 dry; 5 to 7 moist E2—13 to 26 inches; pink (7.5YR 8/4) very gravelly Chroma: 2 to 4 sandy loam, light brown (7.5YR 6/4) moist; Texture: Sandy loam or loam weak fine and medium subangular blocky Clay content: 5 to 15 percent 232 Soil Survey
Content of rock fragments: 35 to 70 percent—0 to Flooding: None 10 percent angular cobbles; 35 to 60 percent Available water capacity: Mainly 2.8 inches angular pebbles Reaction: pH 5.6 to 7.3 A typical soil description with range in characteristics is included, in alphabetical order, in E and Bt horizon this section. Hue: E part—2.5Y, 10YR, or 7.5YR; B part—2.5Y, 10YR, 7.5YR, or 5YR Management Value: E part—6 to 8 dry, 5 to 7 moist; B part— For management information about this map unit, 4 to 6 dry, 4 or 5 moist see appropriate sections in Part II of this publication. Chroma: E part—2 to 4; B part—3 or 4 Texture: Fine sandy loam, sandy loam, or loam Clay content: 5 to 15 percent; lamellae have less 86E—Winkler gravelly loam, than 5 percent increase in clay 15 to 35 percent slopes Content of rock fragments: 60 to 85 percent— 10 to 25 percent angular cobbles; 50 to Setting 60 percent angular pebbles Reaction: pH 5.6 to 6.5 Landform: Mountains Slope: 15 to 35 percent C horizon Elevation: 4,400 to 6,500 feet Hue: 7.5YR or 10YR Mean annual precipitation: 18 to 24 inches Value: 5 to 7 dry; 4 or 5 moist Frost-free period: 70 to 90 days Chroma: 2 or 3 Texture: Sandy loam or fine sandy loam Composition Clay content: 5 to 15 percent Major Components Content of rock fragments: 60 to 85 percent— Winkler and similar soils: 85 percent 10 to 25 percent angular cobbles; 50 to 60 percent angular pebbles Minor Components Reaction: pH 5.6 to 6.5 Areas of rock outcrop: 0 to 8 percent Bignell soils: 0 to 7 percent Major Component Description 86D—Winkler gravelly loam, 8 to 15 percent slopes Surface layer texture: Gravelly loam Depth class: Very deep (more than 60 inches) Drainage class: Somewhat excessively drained Setting Dominant parent material: Colluvium Landform: Mountains Native plant cover type: Forestland Slope: 8 to 15 percent Flooding: None Elevation: 4,400 to 6,500 feet Available water capacity: Mainly 2.8 inches Mean annual precipitation: 18 to 24 inches Frost-free period: 70 to 90 days A typical soil description with range in characteristics is included, in alphabetical order, in Composition this section. Major Components Management Winkler and similar soils: 85 percent For management information about this map unit, Minor Components see appropriate sections in Part II of this publication. Areas of rock outcrop: 0 to 8 percent Bignell soils: 0 to 7 percent Major Component Description 86F—Winkler gravelly loam, 35 to 60 percent slopes Surface layer texture: Gravelly loam Depth class: Very deep (more than 60 inches) Setting Drainage class: Somewhat excessively drained Dominant parent material: Colluvium Landform: Mountains Native plant cover type: Forestland Slope: 35 to 60 percent Powell County Area, Montana—Part I 233
Elevation: 4,400 to 6,500 feet Drainage class: Somewhat excessively drained Mean annual precipitation: 18 to 24 inches Dominant parent material: Colluvium Frost-free period: 70 to 90 days Native plant cover type: Forestland Flooding: None Composition Available water capacity: Mainly 2.8 inches Major Components Winkler and similar soils: 85 percent A typical soil description with range in characteristics is included, in alphabetical order, in Minor Components this section. Areas of rock outcrop: 0 to 8 percent Bignell soils: 0 to 7 percent Management Major Component Description For management information about this map unit, see appropriate sections in Part II of this publication. Surface layer texture: Gravelly loam Depth class: Very deep (more than 60 inches) Drainage class: Somewhat excessively drained Dominant parent material: Colluvium 786D—Winkler gravelly loam, cool, Native plant cover type: Forestland 8 to 15 percent slopes Flooding: None Available water capacity: Mainly 2.8 inches Setting Landform: Mountains A typical soil description with range in Slope: 8 to 15 percent characteristics is included, in alphabetical order, in Elevation: 4,400 to 6,500 feet this section. Mean annual precipitation: 18 to 24 inches Management Frost-free period: 70 to 90 days For management information about this map unit, Composition see appropriate sections in Part II of this publication. Major Components Winkler and similar soils: 85 percent 86G—Winkler gravelly loam, Minor Components 60 to 80 percent slopes Areas of rock outcrop: 0 to 5 percent Yreka soils: 0 to 5 percent Setting Soils that are shallow to bedrock: 0 to 5 percent Landform: Mountains Major Component Description Slope: 60 to 80 percent Surface layer texture: Gravelly loam Elevation: 4,400 to 6,500 feet Depth class: Very deep (more than 60 inches) Mean annual precipitation: 18 to 24 inches Drainage class: Somewhat excessively drained Frost-free period: 70 to 90 days Dominant parent material: Colluvium Composition Native plant cover type: Forestland Flooding: None Major Components Available water capacity: Mainly 2.8 inches Winkler and similar soils: 85 percent Minor Components A typical soil description with range in Areas of rock outcrop: 0 to 8 percent characteristics is included, in alphabetical order, in Bignell soils: 0 to 7 percent this section. Major Component Description Management Surface layer texture: Gravelly loam For management information about this map unit, Depth class: Very deep (more than 60 inches) see appropriate sections in Part II of this publication. 234 Soil Survey
786E—Winkler gravelly loam, cool, Minor Components 15 to 35 percent slopes Areas of rock outcrop: 0 to 5 percent Soils that are shallow to bedrock: 0 to 5 percent Yreka soils: 0 to 5 percent Setting Major Component Description Landform: Mountains Slope: 15 to 35 percent Surface layer texture: Gravelly loam Elevation: 4,400 to 6,500 feet Depth class: Very deep (more than 60 inches) Mean annual precipitation: 18 to 24 inches Drainage class: Somewhat excessively drained Frost-free period: 70 to 90 days Dominant parent material: Colluvium Native plant cover type: Forestland Composition Flooding: None Major Components Available water capacity: Mainly 2.8 inches Winkler and similar soils: 85 percent A typical soil description with range in Minor Components characteristics is included, in alphabetical order, in Areas of rock outcrop: 0 to 5 percent this section. Soils that are shallow to bedrock: 0 to 5 percent Yreka soils: 0 to 5 percent Management Major Component Description For management information about this map unit, see appropriate sections in Part II of this publication. Surface layer texture: Gravelly loam Depth class: Very deep (more than 60 inches) Drainage class: Somewhat excessively drained Dominant parent material: Colluvium 786G—Winkler gravelly loam, cool, Native plant cover type: Forestland 60 to 80 percent slopes Flooding: None Available water capacity: Mainly 2.8 inches Setting A typical soil description with range in Landform: Mountains characteristics is included, in alphabetical order, in Slope: 60 to 80 percent this section. Elevation: 4,400 to 6,500 feet Mean annual precipitation: 18 to 24 inches Management Frost-free period: 70 to 90 days For management information about this map unit, Composition see appropriate sections in Part II of this publication. Major Components Winkler and similar soils: 85 percent 786F—Winkler gravelly loam, cool, 35 to 60 percent slopes Minor Components Areas of rock outcrop: 0 to 5 percent Soils that are shallow to bedrock: 0 to 5 percent Setting Yreka soils: 0 to 5 percent Landform: Mountains Major Component Description Slope: 35 to 60 percent Elevation: 4,400 to 6,500 feet Surface layer texture: Gravelly loam Mean annual precipitation: 18 to 24 inches Depth class: Very deep (more than 60 inches) Frost-free period: 70 to 90 days Drainage class: Somewhat excessively drained Dominant parent material: Colluvium Composition Native plant cover type: Forestland Major Components Flooding: None Winkler and similar soils: 85 percent Available water capacity: Mainly 2.8 inches Powell County Area, Montana—Part I 235
A typical soil description with range in A typical soil description with range in characteristics is included, in alphabetical order, in characteristics is included, in alphabetical order, in this section. this section. Management Management For management information about this map unit, For management information about this map unit, see appropriate sections in Part II of this publication. see appropriate sections in Part II of this publication.
886E—Winkler-Rubble land-Rock outcrop 886F—Winkler-Rubble land-Rock outcrop complex, 15 to 35 percent slopes complex, 35 to 60 percent slopes
Setting Setting Landform: Landform: • Winkler—Mountains • Winkler—Mountains • Rubble land—Mountains • Rubble land—Mountains • Rock outcrop—Mountains • Rock outcrop—Mountains Slope: 15 to 35 percent Slope: 35 to 60 percent Elevation: 4,400 to 6,500 feet Elevation: 4,400 to 6,500 feet Mean annual precipitation: 18 to 24 inches Mean annual precipitation: 18 to 24 inches Frost-free period: 70 to 90 days Frost-free period: 70 to 90 days Composition Composition Major Components Major Components Winkler and similar soils: 50 percent Winkler and similar soils: 50 percent Rubble land: 20 percent Rubble land: 20 percent Rock outcrop: 15 percent Rock outcrop: 15 percent Minor Components Minor Components Soils that have slopes more than 35 percent: 0 to Soils that have slopes more than 35 percent: 0 to 5 percent 5 percent Whitecow soils: 0 to 5 percent Bignell soils: 0 to 5 percent Tevis soils: 0 to 5 percent Whitecow soils: 0 to 5 percent Major Component Description Major Component Description Winkler Winkler Surface layer texture: Gravelly loam Surface layer texture: Gravelly loam Depth class: Very deep (more than 60 inches) Depth class: Very deep (more than 60 inches) Drainage class: Somewhat excessively drained Drainage class: Somewhat excessively drained Dominant parent material: Colluvium Dominant parent material: Colluvium Native plant cover type: Forestland Native plant cover type: Forestland Flooding: None Flooding: None Available water capacity: Mainly 2.8 inches Available water capacity: Mainly 2.8 inches
Rubble land Rubble land Definition: Areas having more than 90 percent Definition: Areas having more than 90 percent boulders, stones, and cobbles on the surface, boulders, stones, and cobbles on the surface, supporting little or no vegetation supporting little or no vegetation
Rock outcrop Rock outcrop Definition: Areas of exposed bedrock Definition: Areas of exposed bedrock 236 Soil Survey
A typical soil description with range in A typical soil description with range in characteristics is included, in alphabetical order, in characteristics is included, in alphabetical order, in this section. this section. Management Management For management information about this map unit, For management information about this map unit, see appropriate sections in Part II of this publication. see appropriate sections in Part II of this publication.
886G—Winkler-Rubble land-Rock outcrop Winspect Series complex, 60 to 80 percent slopes Depth class: Very deep Drainage class: Well drained Setting Permeability: Moderately slow Landform: Landform: Moraines and alluvial fans • Winkler—Mountains Parent material: Alluvium and alpine till • Rubble land—Mountains Slope range: 2 to 60 percent • Rock outcrop—Mountains Elevation range: 3,800 to 5,800 feet Slope: 60 to 80 percent Annual precipitation: 15 to 19 inches Elevation: 4,400 to 6,500 feet Annual air temperature: 39 to 44 degrees F Mean annual precipitation: 18 to 24 inches Frost-free period: 70 to 90 days Frost-free period: 70 to 90 days Taxonomic Class: Loamy-skeletal, mixed, Composition superactive, frigid Typic Calciustolls Major Components Typical Pedon Winkler and similar soils: 50 percent Rubble land: 20 percent Winspect gravelly loam, 8 to 15 percent slopes, in an Rock outcrop: 15 percent area of rangeland, 2,100 feet north and 1,000 feet east of the southwest corner of sec. 9, T. 10 N., Minor Components R. 7 W. Soils that have slopes more than 80 percent: 0 to 5 percent A—0 to 5 inches; dark grayish brown (10YR 4/2) Whitecow soils: 0 to 5 percent gravelly loam, black (10YR 2/1) moist; weak fine Tevis soils: 0 to 5 percent granular structure; soft, friable, nonsticky, nonplastic; many very fine, common fine, and Major Component Description few medium roots; many very fine discontinuous Winkler interstitial pores; 5 percent cobbles and Surface layer texture: Gravelly loam 15 percent pebbles; slightly effervescent; Depth class: Very deep (more than 60 inches) moderately alkaline; clear smooth boundary. Drainage class: Somewhat excessively drained Ak—5 to 11 inches; brown (10YR 5/3) very gravelly Dominant parent material: Colluvium loam, dark brown (10YR 3/3) moist; weak fine Native plant cover type: Forestland and medium subangular blocky structure parting Flooding: None to weak fine granular structure; soft, very friable, Available water capacity: Mainly 2.8 inches slightly sticky, nonplastic; common very fine and few fine and medium roots; common very fine Rubble land discontinuous interstitial pores; 10 percent Definition: Areas having more than 90 percent cobbles and 40 percent pebbles; disseminated boulders, stones, and cobbles on the surface, lime; violently effervescent; moderately alkaline; supporting little or no vegetation clear smooth boundary. Bk1—11 to 20 inches; light brownish gray (10YR 6/2) Rock outcrop very gravelly loam, dark grayish brown (2.5Y 4/2) Definition: Areas of exposed bedrock moist; weak fine subangular blocky structure; soft, Powell County Area, Montana—Part I 237
very friable, slightly sticky, nonplastic; common Clay content: 20 to 35 percent very fine and few fine and medium roots; Content of rock fragments: 35 to 60 percent— common very fine discontinuous interstitial pores; 10 to 25 percent cobbles; 25 to 35 percent 10 percent cobbles and 50 percent pebbles; pebbles disseminated lime; violently effervescent; Calcium carbonate equivalent: 15 to 40 percent moderately alkaline; clear smooth boundary. Reaction: pH 7.4 to 8.4 Bk2—20 to 60 inches; light gray (10YR 7/2) very gravelly loam, grayish brown (2.5Y 5/2) moist; weak fine subangular blocky structure; soft, 39C—Winspect gravelly loam, very friable, slightly sticky, nonplastic; common 4 to 8 percent slopes very fine and few fine and medium roots; common very fine discontinuous interstitial Setting pores; 10 percent cobbles and 35 percent Landform: Alluvial fans pebbles; disseminated lime; violently Slope: 4 to 8 percent effervescent; moderately alkaline. Elevation: 4,400 to 5,800 feet Mean annual precipitation: 15 to 19 inches Range in Characteristics Frost-free period: 70 to 90 days Soil temperature: 41 to 47 degrees F Composition Thickness of the mollic epipedon: 7 to 14 inches Major Components A horizon Winspect and similar soils: 85 percent Value: 4 or 5 dry; 2 or 3 moist Chroma: 1 or 2 Minor Components Clay content: 20 to 25 percent Soils that have slopes more than 15 percent: 0 to Content of rock fragments: 15 to 35 percent—0 to 5 percent 5 percent stones; 5 to 15 percent cobbles; Winspect cobbly loam: 0 to 4 percent 10 to 15 percent pebbles Soils that are moderately deep: 0 to 3 percent Calcium carbonate equivalent: 5 to 10 percent Areas of rock outcrop: 0 to 3 percent Reaction: pH 7.4 to 8.4 Major Component Description Ak horizon Surface layer texture: Gravelly loam Value: 4 or 5 dry; 2 or 3 moist Depth class: Very deep (more than 60 inches) Chroma: 2 or 3 Drainage class: Well drained Texture: Loam or clay loam Dominant parent material: Alluvium Clay content: 20 to 30 percent Native plant cover type: Rangeland Content of rock fragments: 20 to 60 percent—5 to Flooding: None 20 percent cobbles; 10 to 40 percent pebbles Available water capacity: Mainly 6.1 inches Calcium carbonate equivalent: 10 to 40 percent Reaction: pH 7.4 to 8.4 A typical soil description with range in Bk1 horizon characteristics is included, in alphabetical order, in Hue: 10YR or 2.5Y this section. Value: 5 or 6 dry; 4 or 5 moist Management Chroma: 2 or 3 Texture: Loam, clay loam, or sandy clay loam For management information about this map unit, Clay content: 20 to 35 percent see appropriate sections in Part II of this publication. Content of rock fragments: 35 to 60 percent—5 to 10 percent cobbles; 30 to 50 percent pebbles Calcium carbonate equivalent: 15 to 40 percent 39D—Winspect gravelly loam, Reaction: pH 7.4 to 8.4 8 to 15 percent slopes Bk2 horizon Setting Hue: 10YR or 2.5Y Value: 5 to 7 dry; 4 to 6 moist Landform: Alluvial fans Chroma: 2 or 3 Slope: 8 to 15 percent Texture: Loam, clay loam, or sandy clay loam Elevation: 4,400 to 5,800 feet 238 Soil Survey
Mean annual precipitation: 15 to 19 inches Major Component Description Frost-free period: 70 to 90 days Surface layer texture: Gravelly loam Composition Depth class: Very deep (more than 60 inches) Drainage class: Well drained Major Components Dominant parent material: Alluvium Winspect and similar soils: 85 percent Native plant cover type: Rangeland Minor Components Flooding: None Soils that have slopes more than 15 percent: 0 to Available water capacity: Mainly 6.1 inches 5 percent Winspect cobbly loam: 0 to 4 percent A typical soil description with range in Soils that are moderately deep: 0 to 3 percent characteristics is included, in alphabetical order, in Areas of rock outcrop: 0 to 3 percent this section. Major Component Description Management Surface layer texture: Gravelly loam For management information about this map unit, Depth class: Very deep (more than 60 inches) see appropriate sections in Part II of this publication. Drainage class: Well drained Dominant parent material: Alluvium Native plant cover type: Rangeland 39F—Winspect gravelly loam, Flooding: None 35 to 60 percent slopes Available water capacity: Mainly 6.1 inches Setting A typical soil description with range in Landform: Alluvial fans characteristics is included, in alphabetical order, in Slope: 35 to 60 percent this section. Elevation: 4,400 to 5,800 feet Management Mean annual precipitation: 15 to 19 inches Frost-free period: 70 to 90 days For management information about this map unit, see appropriate sections in Part II of this publication. Composition Major Components 39E—Winspect gravelly loam, Winspect and similar soils: 85 percent 15 to 35 percent slopes Minor Components Soils that have slopes more than 60 percent: 0 to Setting 5 percent Winspect cobbly loam: 0 to 4 percent Landform: Alluvial fans Areas of rock outcrop: 0 to 3 percent Slope: 15 to 35 percent Moderately deep soils: 0 to 3 percent Elevation: 4,400 to 5,800 feet Mean annual precipitation: 15 to 19 inches Major Component Description Frost-free period: 70 to 90 days Surface layer texture: Gravelly loam Composition Depth class: Very deep (more than 60 inches) Drainage class: Well drained Major Components Dominant parent material: Alluvium Winspect and similar soils: 85 percent Native plant cover type: Rangeland Minor Components Flooding: None Soils that have slopes more than 35 percent: 0 to Available water capacity: Mainly 6.1 inches 5 percent Winspect cobbly loam: 0 to 4 percent A typical soil description with range in Areas of rock outcrop: 0 to 3 percent characteristics is included, in alphabetical order, in Soils that are moderately deep: 0 to 3 percent this section. Powell County Area, Montana—Part I 239
Management 15 percent cobbles, and 25 percent pebbles; moderately acid; clear wavy boundary. For management information about this map unit, Bt1—23 to 38 inches; brown (7.5YR 5/4) very gravelly see appropriate sections in Part II of this publication. clay loam, brown (7.5YR 4/4) moist; moderate medium subangular blocky structure; hard, firm, Worock Series moderately sticky and moderately plastic; common fine and medium roots; few very fine Depth class: Very deep and fine discontinuous pores; common distinct Drainage class: Well drained clay films on faces of peds; 5 percent stones, Permeability: Moderately slow 15 percent cobbles, and 40 percent pebbles; Landform: Mountains moderately acid; clear wavy boundary. Parent material: Colluvium derived from volcanic rock Bt2—38 to 60 inches; brown (7.5YR 5/4) very gravelly and argillite clay loam, strong brown (7.5YR 4/6) moist; Slope range: 8 to 60 percent moderate medium subangular blocky structure; Elevation range: 4,600 to 7,500 feet hard, very firm, moderately sticky and moderately Annual precipitation: 20 to 30 inches plastic; few fine and medium roots; few very fine Annual air temperature: 35 to 38 degrees F and fine discontinuous pores; many distinct Frost-free period: 30 to 70 days clay films on faces of peds; 5 percent stones, 15 percent cobbles, and 40 percent pebbles; Taxonomic Class: Loamy-skeletal, mixed, moderately acid. superactive Eutric Haplocryalfs Range in Characteristics Typical Pedon Worock gravelly loam, in an area of Worock, cool- Soil temperature: 37 to 45 degrees F Loberg complex, 8 to 15 percent slopes, in an area of Moisture control section: Between depths of 4 and woodland, 1,930 feet south and 2,285 feet east of the 12 inches; never dry in all parts when not frozen northwest corner of sec. 21, T. 12 N., R. 10 W. E horizons Oi—2 inches to 0; undecomposed and slightly Value: 6 or 7 dry; 3 to 5 moist decomposed forest litter. Chroma: 2 to 4 or 6 E1—0 to 5 inches; pale brown (10YR 6/3) gravelly Clay content: 15 to 25 percent loam, dark brown (10YR 3/3) moist; weak fine Content of rock fragments: 15 to 35 percent—0 to granular structure; soft, friable, nonsticky, 15 percent cobbles; 15 to 20 percent pebbles nonplastic; many medium and coarse and few Reaction: pH 5.1 to 6.5 very fine roots; many very fine and fine irregular E/Bt horizon pores; 15 percent pebbles; strongly acid; clear Hue: E part—10YR or 7.5YR; B part—10YR or wavy boundary. 7.5YR E2—5 to 18 inches; light gray (10YR 7/2) cobbly Value: E part—6 or 7 dry, 3 to 5 moist; loam, brown (10YR 4/3) moist; weak fine and B part—5 or 6 dry, 4 or 5 moist medium subangular blocky structure parting to Chroma: E part—2, 3, 4, 5, or 6; B part—4 or 6 moderate fine granular structure; soft, friable, Texture: E part—loam or sandy loam; B part— nonsticky, nonplastic; many fine and medium and clay loam; mixed—loam or clay loam few very fine roots; common very fine and fine Clay content: E part—15 to 27 percent; B part— tubular pores; 15 percent cobbles and 20 percent 27 to 30 percent; mixed—18 to 30 percent pebbles; moderately acid; gradual wavy Content of rock fragments: 20 to 60 percent—5 to boundary. 20 percent stones; 5 to 15 percent cobbles; E/Bt—18 to 23 inches; 85 percent is pinkish gray 10 to 25 percent pebbles (7.5YR 7/2) very cobbly loam, brown (7.5YR 5/4) Reaction: pH 5.1 to 6.5 moist (E part); 15 percent is brown (7.5YR 5/4) very cobbly clay loam, brown (7.5YR 4/4) moist Bt horizons (B part); moderate medium subangular blocky Hue: 10YR or 7.5YR structure; hard, firm, moderately sticky and Value: 5 to 7 dry; 4 or 5 moist moderately plastic; few very fine and common Chroma: 4 or 6 fine and medium roots; common very fine and Texture: Loam, clay loam, or sandy clay loam fine discontinuous pores; 5 percent stones, Clay content: 25 to 35 percent 240 Soil Survey
Content of rock fragments: 35 to 65 percent—0 to Composition 10 percent stones; 5 to 15 percent cobbles; Major Components 25 to 45 percent pebbles Worock and similar soils: 85 percent Reaction: pH 5.6 to 6.5 Minor Components Soils that are shallow: 0 to 4 percent 96D—Worock gravelly loam, cool, Evaro soils: 0 to 3 percent 8 to 15 percent slopes Danaher soils: 0 to 3 percent Areas of rock outcrop: 0 to 2 percent Setting Areas of rubble land: 0 to 2 percent Landform: Mountains Major Component Description Slope: 8 to 15 percent Surface layer texture: Gravelly loam Elevation: 5,600 to 7,500 feet Depth class: Very deep (more than 60 inches) Mean annual precipitation: 20 to 30 inches Drainage class: Well drained Frost-free period: 30 to 70 days Dominant parent material: Colluvium Composition Native plant cover type: Forestland Flooding: None Major Components Available water capacity: Mainly 5.5 inches Worock and similar soils: 85 percent Minor Components A typical soil description with range in Soils that are shallow: 0 to 4 percent characteristics is included, in alphabetical order, in Evaro soils: 0 to 3 percent this section. Danaher soils: 0 to 4 percent Management Areas of rock outcrop: 0 to 2 percent Areas of rubble land: 0 to 2 percent For management information about this map unit, see appropriate sections in Part II of this publication. Major Component Description Surface layer texture: Gravelly loam Depth class: Very deep (more than 60 inches) 96F—Worock gravelly loam, cool, Drainage class: Well drained 35 to 60 percent slopes Dominant parent material: Colluvium Native plant cover type: Forestland Setting Flooding: None Available water capacity: Mainly 4.4 inches Landform: Mountains Slope: 35 to 60 percent A typical soil description with range in Elevation: 5,600 to 7,500 feet characteristics is included, in alphabetical order, in Mean annual precipitation: 20 to 30 inches this section. Frost-free period: 30 to 70 days Management Composition For management information about this map unit, Major Components see appropriate sections in Part II of this publication. Worock and similar soils: 85 percent Minor Components 96E—Worock gravelly loam, cool, Soils that are shallow: 0 to 4 percent 15 to 35 percent slopes Evaro soils: 0 to 3 percent Danaher soils: 0 to 3 percent Areas of rock outcrop: 0 to 2 percent Setting Areas of rubble land: 0 to 2 percent Landform: Mountains Major Component Description Slope: 15 to 35 percent Elevation: 5,600 to 7,500 feet Surface layer texture: Gravelly loam Mean annual precipitation: 20 to 30 inches Depth class: Very deep (more than 60 inches) Frost-free period: 30 to 70 days Drainage class: Well drained Powell County Area, Montana—Part I 241
Dominant parent material: Colluvium Flooding: None Native plant cover type: Forestland Available water capacity: Mainly 5.0 inches Flooding: None Available water capacity: Mainly 5.5 inches A typical soil description with range in characteristics is included, in alphabetical order, in A typical soil description with range in this section. characteristics is included, in alphabetical order, in Management this section. For management information about this map unit, Management see appropriate sections in Part II of this publication. For management information about this map unit, see appropriate sections in Part II of this publication. 196F—Worock-Loberg complex, 35 to 60 percent slopes 196E—Worock-Loberg complex, 15 to 35 percent slopes Setting Landform: Setting • Worock—Mountains Landform: • Loberg—Mountains • Worock—Mountains Slope: • Loberg—Mountains • Worock—35 to 60 percent Slope: • Loberg—35 to 60 percent • Worock—15 to 35 percent Elevation: 4,600 to 7,500 feet • Loberg—15 to 35 percent Mean annual precipitation: 20 to 30 inches Elevation: 4,600 to 7,500 feet Frost-free period: 30 to 70 days Mean annual precipitation: 20 to 30 inches Composition Frost-free period: 30 to 70 days Major Components Composition Worock and similar soils: 50 percent Major Components Loberg and similar soils: 35 percent Worock and similar soils: 50 percent Minor Components Loberg and similar soils: 35 percent Soils that are gravelly loam throughout: 0 to 8 percent Minor Components Soils that have slopes more than 60 percent: 0 to Soils that are gravelly loam throughout: 0 to 8 percent 7 percent Soils that have slopes more than 35 percent: 0 to Major Component Description 7 percent Worock Major Component Description Surface layer texture: Gravelly loam Worock Depth class: Very deep (more than 60 inches) Surface layer texture: Gravelly loam Drainage class: Well drained Depth class: Very deep (more than 60 inches) Dominant parent material: Colluvium Drainage class: Well drained Native plant cover type: Forestland Dominant parent material: Colluvium Flooding: None Native plant cover type: Forestland Available water capacity: Mainly 5.5 inches Flooding: None Available water capacity: Mainly 5.5 inches Loberg Surface layer texture: Clay loam Loberg Depth class: Very deep (more than 60 inches) Surface layer texture: Clay loam Drainage class: Well drained Depth class: Very deep (more than 60 inches) Dominant parent material: Colluvium Drainage class: Well drained Native plant cover type: Forestland Dominant parent material: Colluvium Flooding: None Native plant cover type: Forestland Available water capacity: Mainly 5.0 inches 242 Soil Survey
A typical soil description with range in 396E—Worock gravelly loam, characteristics is included, in alphabetical order, in 15 to 35 percent slopes this section. Management Setting For management information about this map unit, Landform: Mountains see appropriate sections in Part II of this publication. Slope: 15 to 35 percent Elevation: 5,600 to 7,500 feet Mean annual precipitation: 20 to 30 inches 396D—Worock gravelly loam, Frost-free period: 30 to 70 days 8 to 15 percent slopes Composition Setting Major Components Worock and similar soils: 85 percent Landform: Mountains Slope: 8 to 15 percent Minor Components Elevation: 5,600 to 7,500 feet Areas of rock outcrop: 0 to 3 percent Mean annual precipitation: 20 to 30 inches Soils that are moderately deep: 0 to 3 percent Frost-free period: 30 to 70 days Poorly drained soils: 0 to 3 percent Loberg soils: 0 to 3 percent Composition Soils that have slopes more than 35 percent: 0 to Major Components 3 percent Worock and similar soils: 85 percent Major Component Description Minor Components Surface layer texture: Gravelly loam Areas of rock outcrop: 0 to 3 percent Depth class: Very deep (more than 60 inches) Soils that are moderately deep: 0 to 3 percent Drainage class: Well drained Poorly drained soils: 0 to 3 percent Dominant parent material: Colluvium Loberg soils: 0 to 3 percent Native plant cover type: Forestland Soils that have slopes more than 15 percent: 0 to Flooding: None 3 percent Available water capacity: Mainly 5.5 inches Major Component Description A typical soil description with range in Surface layer texture: Gravelly loam characteristics is included, in alphabetical order, in Depth class: Very deep (more than 60 inches) this section. Drainage class: Well drained Dominant parent material: Colluvium Management Native plant cover type: Forestland For management information about this map unit, Flooding: None see appropriate sections in Part II of this publication. Available water capacity: Mainly 5.5 inches
A typical soil description with range in 396F—Worock gravelly loam, characteristics is included, in alphabetical order, in 35 to 60 percent slopes this section. Management Setting For management information about this map unit, Landform: Mountains see appropriate sections in Part II of this publication. Slope: 35 to 60 percent Powell County Area, Montana—Part I 243
Elevation: 5,600 to 7,500 feet Minor Components Mean annual precipitation: 20 to 30 inches Soils that have slopes more than 15 percent: 0 to Frost-free period: 30 to 70 days 5 percent Poorly drained soils: 0 to 5 percent Composition Danaher soils: 0 to 5 percent Major Components Major Component Description Worock and similar soils: 85 percent Worock Minor Components Surface layer texture: Gravelly loam Areas of rock outcrop: 0 to 3 percent Depth class: Very deep (more than 60 inches) Soils that are moderately deep: 0 to 3 percent Drainage class: Well drained Loberg soils: 0 to 3 percent Dominant parent material: Colluvium Poorly drained soils: 0 to 2 percent Native plant cover type: Forestland Soils that have an extremely gravelly subsoil: 0 to Flooding: None 2 percent Available water capacity: Mainly 5.5 inches Soils that have slopes more than 60 percent: 0 to 2 percent Loberg Major Component Description Surface layer texture: Clay loam Depth class: Very deep (more than 60 inches) Surface layer texture: Gravelly loam Drainage class: Well drained Depth class: Very deep (more than 60 inches) Dominant parent material: Material weathered from Drainage class: Well drained igneous rocks Dominant parent material: Colluvium Native plant cover type: Forestland Native plant cover type: Forestland Flooding: None Flooding: None Available water capacity: Mainly 5.0 inches Available water capacity: Mainly 5.5 inches A typical soil description with range in A typical soil description with range in characteristics is included, in alphabetical order, in characteristics is included, in alphabetical order, in this section. this section. Management Management For management information about this map unit, For management information about this map unit, see appropriate sections in Part II of this publication. see appropriate sections in Part II of this publication.
596D—Worock, cool-Loberg complex, 596E—Worock, cool-Loberg complex, 8 to 15 percent slopes 15 to 35 percent slopes
Setting Setting Landform: Landform: • Worock—Mountains • Worock—Mountains • Loberg—Mountains • Loberg—Mountains Slope: Slope: • Worock—8 to 15 percent • Worock—15 to 35 percent • Loberg—8 to 15 percent • Loberg—15 to 35 percent Elevation: 4,600 to 7,500 feet Elevation: 4,600 to 7,500 feet Mean annual precipitation: 20 to 30 inches Mean annual precipitation: 20 to 30 inches Frost-free period: 30 to 70 days Frost-free period: 30 to 70 days Composition Composition Major Components Major Components Worock and similar soils: 50 percent Worock and similar soils: 50 percent Loberg and similar soils: 35 percent Loberg and similar soils: 35 percent 244 Soil Survey
Minor Components Composition Soils that have slopes more than 35 percent: 0 to Major Components 3 percent Worock and similar soils: 50 percent Poorly drained soils: 0 to 3 percent Loberg and similar soils: 35 percent Areas of rock outcrop: 0 to 3 percent Soils that are moderately deep: 0 to 3 percent Minor Components Danaher soils: 0 to 3 percent Areas of rock outcrop: 0 to 4 percent Soils that are moderately deep: 0 to 4 percent Major Component Description Evaro soils: 0 to 4 percent Poorly drained soils: 0 to 3 percent Worock Major Component Description Surface layer texture: Gravelly loam Depth class: Very deep (more than 60 inches) Worock Drainage class: Well drained Surface layer texture: Gravelly loam Dominant parent material: Colluvium Depth class: Very deep (more than 60 inches) Native plant cover type: Forestland Drainage class: Well drained Flooding: None Dominant parent material: Colluvium Available water capacity: Mainly 5.5 inches Native plant cover type: Forestland Flooding: None Loberg Available water capacity: Mainly 5.5 inches Surface layer texture: Clay loam Depth class: Very deep (more than 60 inches) Loberg Drainage class: Well drained Surface layer texture: Clay loam Dominant parent material: Material weathered from Depth class: Very deep (more than 60 inches) igneous rocks Drainage class: Well drained Native plant cover type: Forestland Dominant parent material: Colluvium Flooding: None Native plant cover type: Forestland Available water capacity: Mainly 5.0 inches Flooding: None Available water capacity: Mainly 5.0 inches A typical soil description with range in characteristics is included, in alphabetical order, in A typical soil description with range in this section. characteristics is included, in alphabetical order, in this section. Management Management For management information about this map unit, see appropriate sections in Part II of this publication. For management information about this map unit, see appropriate sections in Part II of this publication.
596F—Worock, cool-Loberg complex, 696E—Worock gravelly loam, dry, 35 to 60 percent slopes 15 to 35 percent slopes
Setting Setting Landform: Landform: Mountains • Worock—Mountains Slope: 15 to 35 percent • Loberg—Mountains Elevation: 5,600 to 7,500 feet Slope: Mean annual precipitation: 20 to 30 inches • Worock—35 to 60 percent Frost-free period: 30 to 70 days • Loberg—35 to 60 percent Composition Elevation: 4,600 to 7,500 feet Mean annual precipitation: 20 to 30 inches Major Components Frost-free period: 30 to 70 days Worock and similar soils: 85 percent Powell County Area, Montana—Part I 245
Minor Components A typical soil description with range in Soils that are shallow: 0 to 4 percent characteristics is included, in alphabetical order, in Evaro soils: 0 to 4 percent this section. Danaher soils: 0 to 3 percent Management Areas of rock outcrop: 0 to 2 percent Areas of rubble land: 0 to 2 percent For management information about this map unit, see appropriate sections in Part II of this publication. Major Component Description Surface layer texture: Gravelly loam Depth class: Very deep (more than 60 inches) 996E—Worock-Rock outcrop complex, Drainage class: Well drained 15 to 35 percent slopes Dominant parent material: Colluvium Native plant cover type: Forestland Flooding: None Setting Available water capacity: Mainly 5.5 inches Landform: Mountains Slope: 15 to 35 percent A typical soil description with range in Elevation: 5,600 to 7,500 feet characteristics is included, in alphabetical order, in Mean annual precipitation: 20 to 30 inches this section. Frost-free period: 30 to 70 days Management Composition For management information about this map unit, see appropriate sections in Part II of this publication. Major Components Worock and similar soils: 50 percent 696F—Worock gravelly loam, dry, Rock outcrop: 35 percent 35 to 60 percent slopes Minor Components Evaro soils: 0 to 4 percent Setting Whitore soils: 0 to 4 percent Soils that have slopes more than 35 percent: 0 to Landform: Mountains 4 percent Slope: 35 to 60 percent Tigeron soils: 0 to 3 percent Elevation: 5,600 to 7,500 feet Mean annual precipitation: 20 to 30 inches Major Component Description Frost-free period: 30 to 70 days Composition Worock Surface layer texture: Gravelly loam Major Components Depth class: Very deep (more than 60 inches) Worock and similar soils: 85 percent Drainage class: Well drained Minor Components Dominant parent material: Colluvium Soils that are shallow: 0 to 4 percent Native plant cover type: Forestland Evaro soils: 0 to 4 percent Flooding: None Danaher soils: 0 to 3 percent Available water capacity: Mainly 5.5 inches Areas of rock outcrop: 0 to 2 percent Areas of rubble land: 0 to 2 percent Rock outcrop Definition: Areas of exposed bedrock Major Component Description Surface layer texture: Gravelly loam A typical soil description with range in Depth class: Very deep (more than 60 inches) characteristics is included, in alphabetical order, in Drainage class: Well drained this section. Dominant parent material: Colluvium Management Native plant cover type: Forestland Flooding: None For management information about this map unit, Available water capacity: Mainly 5.5 inches see appropriate sections in Part II of this publication. 246 Soil Survey
996F—Worock-Rock outcrop complex, Parent material: Colluvium from mixed rock sources 35 to 60 percent slopes and alpine till Slope range: 2 to 80 percent Elevation range: 4,000 to 6,500 feet Setting Annual precipitation: 18 to 26 inches Landform: Annual air temperature: 38 to 42 degrees F • Worock—Mountains Frost-free period: 70 to 90 days • Rock outcrop—Mountains Slope: 35 to 60 percent Taxonomic Class: Loamy-skeletal, mixed, Elevation: 5,600 to 7,500 feet superactive, frigid Typic Haplustalfs Mean annual precipitation: 20 to 30 inches Typical Pedon Frost-free period: 30 to 70 days Yreka gravelly loam, cool, 35 to 60 percent slopes, in Composition an area of woodland, 300 feet south and 550 feet Major Components east of the northwest corner of sec. 30, T. 11 N., Worock and similar soils: 50 percent R. 10 W. Rock outcrop: 35 percent Oi—2 inches to 0; undecomposed and partially Minor Components decomposed twigs and needles. Evaro soils: 0 to 4 percent E—0 to 12 inches; light brownish gray (10YR 6/2) Whitore soils: 0 to 4 percent gravelly loam, brown (10YR 5/3) moist; strong Soils that have slopes more than 60 percent: 0 to medium granular structure; slightly hard, very 4 percent friable, slightly sticky, slightly plastic; many very Very gravelly loamy soils: 0 to 3 percent fine and fine and common medium roots; many very fine and fine pores; 5 percent cobbles and Major Component Description 20 percent pebbles; neutral; clear smooth boundary. Worock E/Bt—12 to 18 inches; 60 percent is light brownish Surface layer texture: Gravelly loam gray (10YR 6/2) gravelly loam, brown (10YR 5/3) Depth class: Very deep (more than 60 inches) moist (E part); 40 percent is brown (10YR 5/3) Drainage class: Well drained gravelly loam, dark brown (10YR 4/3) moist Dominant parent material: Colluvium (B part); moderate medium granular structure; Native plant cover type: Forestland slightly hard, friable, nonsticky, nonplastic; Flooding: None common very fine, fine, and medium and few Available water capacity: Mainly 5.5 inches coarse roots; 10 percent cobbles and 25 percent pebbles; neutral; clear smooth boundary. Rock outcrop Bt—18 to 60 inches; brown (10YR 5/3) very gravelly Definition: Areas of exposed bedrock clay loam, dark brown (10YR 4/3) moist; moderate fine subangular blocky structure; hard, A typical soil description with range in friable, slightly sticky, slightly plastic; few fine, characteristics is included, in alphabetical order, in medium, and coarse roots; common very fine and this section. fine pores; few faint clay films on faces of peds; Management 10 percent cobbles and 35 percent pebbles; neutral. For management information about this map unit, see appropriate sections in Part II of this publication. Range in Characteristics Soil temperature: 40 to 44 degrees F Moisture control section: Between depths of 4 and Yreka Series 12 inches Depth to the argillic horizon: 9 to 24 inches Depth class: Very deep Drainage class: Well drained E horizon Permeability: Moderately slow Value: 5 to 7 dry; 4 or 5 moist Landform: Mountains, hills, and moraines Chroma: 2 or 3 Powell County Area, Montana—Part I 247
Clay content: 7 to 20 percent Drainage class: Well drained Content of rock fragments: 15 to 35 percent—5 to Dominant parent material: Colluvium 15 percent stones and cobbles; 15 to 35 Native plant cover type: Forestland percent pebbles Flooding: None Reaction: pH 5.6 to 7.3 Available water capacity: Mainly 5.6 inches E/Bt horizon A typical soil description with range in Hue: E part—10YR or 7.5YR; B part—10YR or characteristics is included, in alphabetical order, in 7.5YR this section. Value: E part—6 or 7 dry, 5 or 6 moist; B part— 5 or 6 dry, 4 or 5 moist Management Chroma: E part—2 to 4; B part—2 to 4 For management information about this map unit, Texture: Loam or sandy loam see appropriate sections in Part II of this publication. Clay content, mixed: 7 to 25 percent Content of rock fragments: 15 to 35 percent—0 to 10 percent stones and cobbles; 15 to 25 percent pebbles 95E—Yreka gravelly loam, Reaction: pH 5.6 to 7.3 15 to 35 percent slopes Bt horizon Hue: 10YR or 7.5YR Setting Value: 5 or 6 dry; 4 or 5 moist Landform: Mountains Chroma: 2 to 4 Slope: 15 to 35 percent Texture: Clay loam or sandy clay loam Elevation: 4,000 to 6,500 feet Clay content: 20 to 35 percent Mean annual precipitation: 18 to 25 inches Content of rock fragments: 35 to 60 percent—5 to Frost-free period: 70 to 90 days 25 percent stones and cobbles; 30 to 35 percent pebbles Composition Reaction: pH 5.6 to 7.3 Major Components Yreka and similar soils: 85 percent 95D—Yreka gravelly loam, Minor Components 8 to 15 percent slopes Winkler soils: 0 to 4 percent Areas of rock outcrop: 0 to 3 percent Setting Soils that are shallow: 0 to 3 percent Crow soils: 0 to 3 percent Landform: Mountains Areas of rubble land: 0 to 2 percent Slope: 8 to 15 percent Elevation: 4,000 to 6,500 feet Major Component Description Mean annual precipitation: 18 to 25 inches Frost-free period: 70 to 90 days Surface layer texture: Gravelly loam Composition Depth class: Very deep (more than 60 inches) Drainage class: Well drained Major Components Dominant parent material: Colluvium Yreka and similar soils: 85 percent Native plant cover type: Forestland Minor Components Flooding: None Winkler soils: 0 to 4 percent Available water capacity: Mainly 5.6 inches Areas of rock outcrop: 0 to 3 percent Soils that are shallow: 0 to 3 percent A typical soil description with range in Crow soils: 0 to 3 percent characteristics is included, in alphabetical order, in Areas of rubble land: 0 to 2 percent this section. Major Component Description Management Surface layer texture: Gravelly loam For management information about this map unit, Depth class: Very deep (more than 60 inches) see appropriate sections in Part II of this publication. 248
95F—Yreka gravelly loam, Minor Components 35 to 60 percent slopes Crow soils: 0 to 5 percent Bignell soils: 0 to 5 percent Soils that have very gravelly upper layers: 0 to Setting 3 percent Landform: Mountains Major Component Description Slope: 35 to 60 percent Elevation: 4,000 to 6,500 feet Surface layer texture: Gravelly loam Mean annual precipitation: 18 to 25 inches Depth class: Very deep (more than 60 inches) Frost-free period: 70 to 90 days Drainage class: Well drained Dominant parent material: Colluvium Composition Native plant cover type: Forestland Major Components Flooding: None Yreka and similar soils: 85 percent Available water capacity: Mainly 5.6 inches Minor Components A typical soil description with range in Winkler soils: 0 to 4 percent characteristics is included, in alphabetical order, in Areas of rock outcrop: 0 to 3 percent this section. Soils that are shallow: 0 to 3 percent Crow soils: 0 to 3 percent Management Areas of rubble land: 0 to 2 percent For management information about this map unit, see appropriate sections in Part II of this publication. Major Component Description
Surface layer texture: Gravelly loam 195F—Yreka gravelly loam, cool, Depth class: Very deep (more than 60 inches) 35 to 60 percent slopes Drainage class: Well drained Dominant parent material: Colluvium Setting Native plant cover type: Forestland Flooding: None Landform: Mountains Available water capacity: Mainly 5.6 inches Slope: 35 to 60 percent Elevation: 4,000 to 6,500 feet A typical soil description with range in Mean annual precipitation: 18 to 25 inches characteristics is included, in alphabetical order, in Frost-free period: 70 to 90 days this section. Composition Management Major Components For management information about this map unit, Yreka and similar soils: 85 percent see appropriate sections in Part II of this publication. Minor Components Soils that are gravelly loam throughout: 0 to 8 percent Soils that have slopes more than 60 percent: 0 to 195E—Yreka gravelly loam, cool, 7 percent 15 to 35 percent slopes Major Component Description Surface layer texture: Gravelly loam Setting Depth class: Very deep (more than 60 inches) Landform: Mountains Drainage class: Well drained Slope: 15 to 35 percent Dominant parent material: Colluvium Elevation: 4,000 to 6,500 feet Native plant cover type: Forestland Mean annual precipitation: 18 to 25 inches Flooding: None Frost-free period: 70 to 90 days Available water capacity: Mainly 5.6 inches Composition A typical soil description with range in Major Components characteristics is included, in alphabetical order, in Yreka and similar soils: 85 percent this section. Powell County Area, Montana—Part I 249
Management Management For management information about this map unit, For management information about this map unit, see appropriate sections in Part II of this publication. see appropriate sections in Part II of this publication.
995F—Yreka-Rock outcrop complex, 995E—Yreka-Rock outcrop complex, 35 to 60 percent slopes 15 to 35 percent slopes Setting Setting Landform: Landform: • Yreka—Mountains • Yreka—Mountains • Rock outcrop—Mountains • Rock outcrop—Mountains Slope: 35 to 60 percent Slope: 15 to 35 percent Elevation: 4,000 to 6,500 feet Elevation: 4,000 to 6,500 feet Mean annual precipitation: 18 to 25 inches Mean annual precipitation: 18 to 25 inches Frost-free period: 70 to 90 days Frost-free period: 70 to 90 days Composition Composition Major Components Yreka and similar soils: 55 percent Major Components Rock outcrop: 30 percent Yreka and similar soils: 55 percent Minor Components Rock outcrop: 30 percent Soils that are moderately deep: 0 to 4 percent Minor Components Whitecow soils: 0 to 4 percent Soils that are moderately deep: 0 to 4 percent Soils that have slopes more than 60 percent: 0 to Whitecow soils: 0 to 4 percent 4 percent Soils that have slopes more than 35 percent: 0 to Very gravelly loamy soils: 0 to 3 percent 4 percent Major Component Description Very gravelly loamy soils: 0 to 3 percent Yreka Major Component Description Surface layer texture: Gravelly loam Depth class: Very deep (more than 60 inches) Yreka Drainage class: Well drained Surface layer texture: Gravelly loam Dominant parent material: Colluvium Depth class: Very deep (more than 60 inches) Native plant cover type: Forestland Drainage class: Well drained Flooding: None Dominant parent material: Colluvium Available water capacity: Mainly 5.6 inches Native plant cover type: Forestland Flooding: None Rock outcrop Available water capacity: Mainly 5.6 inches Definition: Areas of exposed bedrock
A typical soil description with range in Rock outcrop characteristics is included, in alphabetical order, in Definition: Areas of exposed bedrock this section. Management A typical soil description with range in characteristics is included, in alphabetical order, in For management information about this map unit, this section. see appropriate sections in Part II of this publication.
251
References
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Wallace, C.A. 1987. Generalized geologic map of the Butte 1o x 2o Quadrangle. U.S. Geological Survey Map MF-1925. 253
Glossary
Ablation till. Loose, permeable till deposited during Available water capacity (available moisture the final downwasting of glacial ice. Lenses of capacity). The capacity of soils to hold water crudely sorted sand and gravel are common. available for use by most plants. It is commonly Aeration, soil. The exchange of air in soil with air defined as the difference between the amount of from the atmosphere. The air in a well-aerated soil water at field moisture capacity and the soil is similar to that in the atmosphere; the air in amount at wilting point. It is commonly expressed a poorly aerated soil is considerably higher in as inches of water per inch of soil. The capacity, carbon dioxide and lower in oxygen. in inches, in a 60-inch profile or to a limiting layer Aggregate, soil. Many fine particles held in a single is expressed as: mass or cluster. Natural soil aggregates, such as Very low ...... 0 to 3.75 granules, blocks, or prisms, are called peds. Low ...... 3.75 to 5.0 Clods are aggregates produced by tillage or Moderate ...... 5.0 to 7.5 logging. High ...... more than 7.5 Alkali (sodic) soil. (See Sodic (alkali) soil.) Alluvial fan. A body of alluvium, with overflow of Avalanche chute. The track or path formed by an water and debris flow deposits, whose surface avalanche. forms a segment of a cone that radiates Backslope. The geomorphic component that forms downslope from the point where the stream the steepest inclined surface and principal emerges from a narrow valley onto a less sloping element of many hillslopes. Backslopes in profile surface. Source uplands range in relief and areal are commonly steep and linear and descend to a extent from mountains to gullied terrains on footslope. In terms of gradational process, hillslopes. backslopes are erosional forms produced mainly Alluvium. Material, such as sand, silt, or clay, by mass wasting and running water. deposited on land by streams. Badland. Steep or very steep, commonly nonstony, Alpha,alpha-dipyridyl. A dye that when dissolved in barren land dissected by many intermittent 1N ammonium acetate is used to detect the drainage channels. Badland is most common in presence of reduced iron (Fe II) in the soil. A semiarid and arid regions where streams are positive reaction indicates a type of redox feature. entrenched in soft geologic material. Local relief Animal-unit-month (AUM). The amount of forage generally ranges from 25 to 500 feet. Runoff required by one mature cow of approximately potential is very high, and geologic erosion is 1,000 pounds weight, with or without a calf, for active. 1 month. Basal area. The area of a cross section of a tree, Aquic conditions. Current soil wetness generally referring to the section at breast height characterized by saturation, reduction, and redox and measured outside the bark. It is a measure of features. stand density, commonly expressed in square Area reclaim (in tables). An area difficult to reclaim feet. after the removal of soil for construction and other Basal till. Compact glacial till deposited beneath the uses. Revegetation and erosion control are ice. extremely difficult. Base saturation. The degree to which material Argillite. Weakly metamorphosed mudstone or shale. having cation-exchange properties is saturated Aspect. The direction in which a slope faces. with exchangeable bases (sum of Ca, Mg, Na, Association, soil. A group of soils or miscellaneous and K), expressed as a percentage of the total areas geographically associated in a cation-exchange capacity. characteristic repeating pattern and defined and Base slope. A geomorphic component of hills delineated as a single map unit. consisting of the concave to linear (perpendicular 254 Soil Survey
to the contour) slope that, regardless of the Cable yarding. A method of moving felled trees to a lateral shape, forms an apron or wedge at the nearby central area for transport to a processing bottom of a hillside dominated by colluvium and facility. Most cable yarding systems involve use of slope-wash sediments (for example, slope a drum, a pole, and wire cables in an alluvium). arrangement similar to that of a rod and reel used Bedding planes. Fine strata, less than 5-millimeters for fishing. To reduce friction and soil disturbance, thick, in unconsolidated alluvial, eolian, felled trees generally are reeled in while one end lacustrine, or marine sediment. is lifted or the entire log is suspended. Bedrock. The solid rock that underlies the soil and Calcareous soil. A soil containing enough calcium other unconsolidated material or that is exposed carbonate (commonly combined with magnesium at the surface. carbonate) to effervesce visibly when treated with Bedrock-floored plain. An extensive nearly level to cold, dilute hydrochloric acid. gently rolling or moderately sloping area that is Caliche. A more or less cemented deposit of calcium underlain by hard bedrock and has a slope of 0 to carbonate in soils of warm-temperate, subhumid 8 percent. to arid areas. Caliche occurs as soft, thin layers in Bench terrace. A raised, level or nearly level strip of the soil or as hard, thick beds directly beneath earth constructed on or nearly on a contour, the solum, or it is exposed at the surface by supported by a barrier of rocks or similar erosion. material, and designed to make the soil suitable California bearing ratio (CBR). The load-supporting for tillage and to prevent accelerated erosion. capacity of a soil as compared to that of standard Blowout. A shallow depression from which all or crushed limestone, expressed as a ratio. First most of the soil material has been removed by standardized in California. A soil having a CBR of the wind. A blowout has a flat or irregular floor 16 supports 16 percent of the load that would be formed by a resistant layer or by an supported by standard crushed limestone, per accumulation of cobbles or gravel. In some unit area, with the same degree of distortion. blowouts, the water table is exposed. Canopy. The leafy crown of trees or shrubs. (See Board foot. A unit of measure of the wood in lumber, Crown.) logs, or trees. The amount of wood in a board Capillary water. Water held as a film around soil 1 foot wide, 1 foot long, and 1 inch thick before particles and in tiny spaces between particles. finishing. Surface tension is the adhesive force that holds Bottom land. The normal flood plain of a stream, capillary water in the soil. subject to flooding. Cation. An ion carrying a positive charge of Boulders. Rock fragments larger than 2 feet electricity. The common soil cations are calcium, (60 centimeters) in diameter. potassium, magnesium, sodium, and hydrogen. Bouldery. Refers to a soil with .01 to 0.1 percent of Cation-exchange capacity. The total amount of the surface covered with boulders. exchangeable cations that can be held by the Bouldery soil material. Soil that is 15 to 35 percent, soil, expressed in terms of milliequivalents per by volume, rock fragments that are dominated by 100 grams of soil at neutrality (pH 7.0) or at some fragments larger than 24 inches (60 centimeters) other stated pH value. The term, as applied to in diameter. soils, is synonymous with base-exchange Breaks. The steep and very steep broken land at the capacity but is more precise in meaning. border of an upland summit that is dissected by Channeled. Refers to a drainage area in which ravines. natural meandering or repeated branching and Breast height. An average height of 4.5 feet above convergence of a streambed have created deeply the ground surface; the point on a tree where incised cuts, either active or abandoned, in diameter measurements are ordinarily taken. alluvial material. Brush management. Use of mechanical, chemical, Channery soil material. A soil that is, by volume, or biological methods to reduce or eliminate more than 15 percent thin, flat fragments of competition from woody vegetation and thus to sandstone, shale, slate, limestone, or schist as allow understory grasses and forbs to recover or much as 6 inches along the longest axis. A single to make conditions favorable for reseeding. Brush piece is called a channer. management increases forage production and Chemical treatment. Control of unwanted vegetation thus reduces the hazard of erosion. It can through the use of chemicals. improve the habitat for some species of wildlife. Powell County Area, Montana—Part I 255
Chiseling. Tillage with an implement having one or Complex slope. Irregular or variable slope. Planning more soil-penetrating points that shatter or or establishing terraces, diversions, and other loosen hard, compacted layers to a depth below water-control structures on a complex slope is normal plow depth. difficult. Cirque. A semicircular, concave, bowl-like area that Complex, soil. A map unit of two or more kinds of has steep faces primarily resulting from erosive soil or miscellaneous areas in such an intricate activity of a mountain glacier. pattern or so small in area that it is not practical Clay. As a soil separate, the mineral soil particles to map them separately at the selected scale of less than 0.002 millimeters in diameter. As a soil mapping. The pattern and proportion of the soils textural class, soil material that is 40 percent or or miscellaneous areas are somewhat similar in more clay, less than 45 percent sand, and less all areas. than 40 percent silt. Concretions. Grains, pellets, or nodules of various Clayey soil. Silty clay, sandy clay, or clay. sizes, shapes, and colors consisting of Clay film. A thin coating of oriented clay on the concentrated compounds or cemented soil surface of a soil aggregate or lining pores or root grains. The composition of most concretions is channels. Synonyms: clay coating, clay skin. unlike that of the surrounding soil. Calcium Claypan. A slowly permeable soil horizon that carbonate and iron oxide are common contains much more clay than the horizons above compounds in concretions. it. A claypan is commonly hard when dry and Conglomerate. A coarse-grained, clastic rock plastic or stiff when wet. composed of rounded or subangular rock Clearcut. A method of forest harvesting that removes fragments more than 2 millimeters in diameter. It the entire stand of trees in one cutting. commonly has a matrix of sand and finer-textured Reproduction is achieved artificially or by natural material. Conglomerate is the consolidated seeding from the adjacent stands. equivalent of gravel. Climax plant community. The stabilized plant Conservation cropping system. Growing crops in community on a particular site. The plant cover combination with needed cultural and reproduces itself and does not change so long as management practices. In a good conservation the environment remains the same. cropping system, the soil-improving crops and Closed depression. A low area completely practices more than offset the effects of the soil- surrounded by higher ground and having no depleting crops and practices. Cropping systems natural outlet. are needed on all tilled soils. Soil-improving Coarse textured soil. Sand or loamy sand. practices in a conservation cropping system Cobble (or cobblestone). A rounded or partly include the use of rotations that contain grasses rounded fragment of rock 3 to 10 inches (7.6 to and legumes and the return of crop residue to the 25 centimeters) in diameter. soil. Other practices include the use of green Cobbly soil material. Material that has 15 to manure crops of grasses and legumes, proper 35 percent, by volume, rounded or partially tillage, adequate fertilization, and weed and pest rounded rock fragments 3 to 10 inches (7.6 to control. 25 centimeters) in diameter. Very cobbly soil Conservation tillage. Any tillage and planting material has 35 to 60 percent of these rock system in which a cover of crop residue is fragments, and extremely cobbly soil material maintained on at least 30 percent of the soil has more than 60 percent. surface after planting in order to reduce the Codominant trees. Trees whose crowns form the hazard of water erosion. In areas where soil general level of the forest canopy and that blowing is the primary concern, a system that receive full light from above but comparatively maintains a cover of at least 1,000 pounds of flat little from the sides. residue of small grain or the equivalent during the COLE (coefficient of linear extensibility). (See critical erosion period. Linear extensibility.) Consistence, soil. Refers to the degree of cohesion Colluvium. Soil material or rock fragments, or both, and adhesion of soil material and its resistance to moved by creep, slide, or local wash and deformation when ruptured. Consistence includes deposited at the base of steep slopes. resistance of soil material to rupture and to Commercial forest. Forestland capable of producing penetration; plasticity, toughness, and stickiness 20 cubic feet or more per acre per year at the of puddled soil material; and the manner in which culmination of mean annual increment. the soil material behaves when subject to 256 Soil Survey
compression. Terms describing consistence are Cutbanks cave (in tables). The walls of excavations defined in the “Soil Survey Manual” (Soil Survey tend to cave in or slough. Division Staff, 1962). Decreasers. The most heavily grazed climax range Consolidated sandstone. Sandstone that disperses plants. Because they are the most palatable, they within a few hours when fragments are placed in are the first to be destroyed by overgrazing. water. The fragments are extremely hard or very Deep soil. A soil that is 40 to 60 inches deep over hard when dry, are not easily crushed, and bedrock or to other material that restricts the cannot be textured by the usual field method. penetration of plant roots. Consolidated shale. Shale that disperses within a Deferred grazing. Postponing grazing or resting few hours when fragments are placed in water. grazing land for a prescribed period. The fragments are extremely hard or very hard Depth, soil. Generally, the thickness of the soil over when dry and are not easily crushed. bedrock. Very deep soils are more than 60 inches Contour stripcropping (or contour farming). deep over bedrock; deep soils, 40 to 60 inches; Growing crops in strips that follow the contour. moderately deep, 20 to 40 inches; shallow, 10 to Strips of grass or close-growing crops are 20 inches; and very shallow, less than 10 inches. alternated with strips of clean-tilled crops or Depth to rock (in tables). Bedrock is too near the summer fallow. surface for the specified use. Control section. The part of the soil on which Dip slope. A slope of the land surface, roughly classification is based. The thickness varies determined by and approximately conforming to among different kinds of soil, but for many it is the dip of the underlying bedrock. that part of the soil profile between depths of Diversion (or diversion terrace). A ridge of earth, 10 inches and 40 or 80 inches. generally a terrace, built to protect downslope Coprogenous earth (sedimentary peat). Fecal areas by diverting runoff from its natural course. material deposited in water by aquatic organisms. Divided-slope farming. A form of field stripcropping Corrosion. Soil-induced electrochemical or chemical in which crops are grown in a systematic action that dissolves or weakens concrete or arrangement of two strips, or bands, across the uncoated steel. slope to reduce the hazard of water erosion. One Cover crop. A close-growing crop grown primarily to strip is in a close-growing crop that provides improve and protect the soil between periods of protection from erosion, and the other strip is in a regular crop production, or a crop grown between crop that provides less protection from erosion. trees and vines in orchards and vineyards. This practice is used where slopes are not long Crop residue management. Returning crop residue enough to permit a full stripcropping pattern to be to the soil, which helps to maintain soil structure, used. organic matter content, and fertility and helps to Dominant trees. Trees whose crowns form the control erosion. general level of the forest canopy and that Cropping system. Growing crops according to a receive full light from above and from the sides. planned system of rotation and management Drainage class (natural). Refers to the frequency practices. and duration of periods of saturation or partial Cross-slope farming. Deliberately conducting saturation during soil formation, as opposed to farming operations on sloping farmland in such a altered drainage, which is commonly the result of way that tillage is across the general slope. artificial drainage or irrigation but may be caused Crown. The upper part of a tree or shrub, including by the sudden deepening of channels or the the living branches and their foliage. blocking of drainage outlets. Seven classes of Culmination of the mean annual increment natural soil drainage are recognized: (CMAI). The average annual increase per acre in Excessively drained.—These soils have very high the volume of a stand. Computed by dividing the and high hydraulic conductivity and a low water- total volume of the stand by its age. As the stand holding capacity. They are not suited to crop increases in age, the mean annual increment production unless irrigated. continues to increase until mortality begins to Somewhat excessively drained.—These soils reduce the rate of increase. The point where the have high hydraulic conductivity and a low water- stand reaches its maximum annual rate of growth holding capacity. Without irrigation, only a narrow is called the culmination of the mean annual range of crops can be grown, and yields are low. increment. Powell County Area, Montana—Part I 257
Well drained.—These soils have an intermediate Dune. A mound, ridge, or hill of loose, windblown water-holding capacity. They retain optimum granular material (generally sand), either bare or amounts of moisture, but they are not wet close covered with vegetation. enough to the surface or long enough during the Ecological site. An area where climate, soil, and growing season to adversely affect yields. relief are sufficiently uniform to produce a distinct Moderately well drained.—These soils are wet natural plant community. An ecological site is the close enough to the surface or long enough that product of all the environmental factors planting or harvesting operations or yields of responsible for its development. It is typified by an some field crops are adversely affected unless a association of species that differ from those on drainage system is installed. Moderately well- other ecological sites in kind and/or proportion of drained soils commonly have a layer with low species or in total production. hydraulic conductivity, a wet layer relatively high Eluviation. The movement of material in true solution in the profile, additions of water by seepage, or or colloidal suspension from one place to another some combination of these. within the soil. Soil horizons that have lost Somewhat poorly drained.—These soils are wet material through eluviation are eluvial; those that close enough to the surface or long enough that have received material are illuvial. planting or harvesting operations or crop growth Endosaturation. A type of saturation of the soil in is markedly restricted unless a drainage system which all horizons between the upper boundary is installed. Somewhat poorly drained soils of saturation and a depth of 2 meters are commonly have a layer with low hydraulic saturated. conductivity, a wet layer high in the profile, Eolian soil material. Earthy parent material additions of water through seepage, or a accumulated through wind action; commonly combination of these. refers to sandy material in dunes or to loess in Poorly drained.—These soils commonly are so blankets on the surface. wet, at or near the surface, during a considerable Ephemeral stream. A stream, or reach of a stream, part of the year that field crops cannot be grown that flows only in direct response to precipitation. under natural conditions. Poorly drained It receives no long-continued supply from melting conditions are caused by a saturated zone, a snow or other source, and its channel is above layer with low hydraulic conductivity, seepage, or the water table at all times. a combination of these. Episaturation. A type of saturation indicating a Very poorly drained.—These soils are wet to the perched water table in a soil in which saturated surface most of the time. The wetness prevents layers are underlain by one or more unsaturated the growth of important crops (except rice) unless layers within 2 meters of the surface. a drainage system is installed. Erosion. The wearing away of the land surface by Drainage, surface. Runoff, or surface flow of water, water, wind, ice, or other geologic agents and by from an area. such processes as gravitational creep. Drainageway. An area of ground at a lower elevation Erosion (geologic). Erosion caused by geologic than the surrounding ground and in which water processes acting over long geologic periods and collects and is drained to a closed depression or resulting in the wearing away of mountains and lake or to a drainageway at a lower elevation. A the building up of such landscape features as drainageway may or may not have distinctly flood plains and coastal plains. Synonym: natural incised channels at its upper reaches or erosion. throughout its course. Erosion (accelerated). Erosion much more rapid Drumlin. A low, smooth, elongated oval hill, mound, than geologic erosion, mainly as a result of or ridge of compact glacial till. The longer axis is human or animal activities or of a catastrophe in parallel to the path of the glacier and commonly nature, such as fire, that exposes the surface. has a blunt nose pointing in the direction from Erosion pavement. A layer of gravel or stones that which the ice approached. remains on the surface after fine particles are Duff. A generally firm organic layer on the surface of removed by sheet or rill erosion. mineral soils. It consists of fallen plant material Escarpment. A relatively continuous and steep slope that is in the process of decomposition and or cliff breaking the general continuity of more includes everything from the litter on the surface gently sloping land surfaces and resulting from to underlying pure humus. erosion or faulting. Synonym: scarp. 258 Soil Survey
Esker. A long, narrow, sinuous, steep-sided ridge material has 35 to 60 percent flagstones, and composed of irregularly stratified sand and gravel extremely flaggy soil material has more than that were deposited by a subsurface stream 60 percent flagstones. flowing between ice walls or through ice tunnels Flagstone. A thin fragment of sandstone, limestone, of a retreating glacier and that were left behind slate, shale, or (rarely) schist 6 to 15 inches when the ice melted. Eskers range from less than (15 to 38 centimeters) long. a mile to more than 100 miles in length and from Flood plain. A nearly level alluvial plain that borders 10 to 100 feet in height. a stream and is subject to flooding unless Even aged. Refers to a stand of trees in which only protected artificially. small differences in age occur between individual Fluvial. Of or pertaining to rivers; produced by river trees. A range of 20 years is allowed. action, as a fluvial plain. Excess fines (in tables). Excess silt and clay in the Foothill. A steeply sloping upland that has relief of as soil. The soil does not provide a source of gravel much as 1,000 feet (300 meters) and fringes a or sand for construction purposes. mountain range or high-plateau escarpment. Excess salt (in tables). Excess water-soluble salts in Footslope. The geomorphic component that forms the soil that restrict the growth of most plants. the inner, gently inclined surface at the base of Extrusive rock. Igneous rock derived from deep- a hillslope. The surface profile is dominantly seated molten matter (magma) emplaced on the concave. In terms of gradational processes, a earth’s surface. footslope is a transitional zone between an Fallow. Cropland left idle in order to restore upslope site of erosion (backslope) and a productivity through accumulation of moisture. downslope site of deposition (toeslope). Summer fallow is common in regions of limited Forb. Any herbaceous plant not a grass or a sedge. rainfall where cereal grain is grown. The soil is Forest cover. All trees and other woody plants tilled for at least one growing season for weed (underbrush) covering the ground in a forest. control and decomposition of plant residue. Forest type. A stand of trees similar in composition Fertility, soil. The quality that enables a soil to and development because of given physical and provide plant nutrients, in adequate amounts and biological factors by which it may be differentiated in proper balance, for the growth of specified from other stands. plants when light, moisture, temperature, tilth, Fragipan. A loamy, brittle subsurface horizon low in and other growth factors are favorable. porosity and content of organic matter and low or Fibric soil material (peat). The least decomposed of moderate in clay but high in silt or very fine sand. all organic soil material. Peat contains a large A fragipan appears cemented and restricts roots. amount of well-preserved fiber that is readily When dry, it is hard or very hard and has a higher identifiable according to botanical origin. Peat has bulk density than the horizon or horizons above. the lowest bulk density and the highest water When moist, it tends to rupture suddenly under content at saturation of all organic soil material. pressure rather than to deform slowly. Field moisture capacity. The moisture content of a Frost action (in tables). Freezing and thawing of soil soil, expressed as a percentage of the ovendry moisture. Frost action can damage roads, weight, after the gravitational, or free, water has buildings and other structures, and plant roots. drained away; the field moisture content 2 or Genesis, soil. The mode of origin of the soil. Refers 3 days after a soaking rain; also called normal especially to the processes or soil-forming factors field capacity, normal moisture capacity, or responsible for the formation of the solum, or true capillary capacity. soil, from the unconsolidated parent material. Fine textured soil. Sandy clay, silty clay, or clay. Giant ripple mark. The undulating surface sculpture Firebreak. Area cleared of flammable material to produced in noncoherent granular materials by stop or help control creeping or running fires. It currents of water and by the agitation of water in also serves as a line from which to work and to wave action during the draining of large glacial facilitate the movement of firefighters and lakes, such as Glacial Lake Missoula. equipment. Designated roads also serve as Glacial drift. Pulverized and other rock material firebreaks. transported by glacial ice and then deposited. First bottom. The normal flood plain of a stream, Also, the sorted and unsorted material deposited subject to frequent or occasional flooding. by streams flowing from glaciers. Flaggy soil material. Material that has, by volume, Glacial outwash. Gravel, sand, and silt, commonly 15 to 35 percent flagstones. Very flaggy soil stratified, deposited by glacial meltwater. Powell County Area, Montana—Part I 259
Glacial till. Unsorted, nonstratified glacial drift Habitat type. An aggregation of all land areas consisting of clay, silt, sand, and boulders capable of producing similar climax plant transported and deposited by glacial ice. communities. Glaciated uplands. Land areas that were previously Hard bedrock. Bedrock that cannot be excavated covered by continental or alpine glaciers and that except by blasting or by the use of special are at a higher elevation than the flood plain. equipment that is not commonly used in Glaciofluvial deposits. Material moved by glaciers construction. and subsequently sorted and deposited by Hardpan. A hardened or cemented soil horizon, or streams flowing from the melting ice. The layer. The soil material is sandy, loamy, or clayey deposits are stratified and occur as kames, and is cemented by iron oxide, silica, calcium eskers, deltas, and outwash plains. carbonate, or other substance. Glaciolacustrine deposits. Material ranging from Head out. To form a flower head. fine clay to sand derived from glaciers and Heavy metal. Inorganic substances that are solid at deposited in glacial lakes mainly by glacial ordinary temperatures and are not soluble in meltwater. Many deposits are interbedded or water. They form oxides and hydroxides that are laminated. basic. Examples are copper, iron, cadmium, zinc, Gleyed soil. Soil that formed under poor drainage, manganese, lead, and arsenic. resulting in the reduction of iron and other Hemic soil material (mucky peat). Organic soil elements in the profile and in gray colors. material intermediate in degree of decomposition Grassed waterway. A natural or constructed between the less decomposed fibric material and waterway, typically broad and shallow, seeded to the more decomposed sapric material. grass as protection against erosion. Conducts High-residue crops. Such crops as small grain and surface water away from cropland. corn used for grain. If properly managed, residue Gravel. Rounded or angular fragments of rock from these crops can be used to control erosion as much as 3 inches (2 millimeters to until the next crop in the rotation is established. 7.6 centimeters) in diameter. An individual These crops return large amounts of organic piece is a pebble. matter to the soil. Gravelly soil material. Soil that is 15 to 35 percent, Hill. A natural elevation of the land surface, rising as by volume, rounded or angular rock fragments up much as 1,000 feet above surrounding lowlands, to 3 inches (7.6 centimeters) in diameter. Very commonly of limited summit area and having a gravelly soil is 35 to 60 percent gravel, and well-defined outline; hillsides generally have extremely gravelly soil is more than 60 percent slopes of more than 8 percent. The distinction gravel by volume. between a hill and a mountain is arbitrary and is Grazeable forestland. Land capable of sustaining dependent on local usage. livestock grazing by producing forage of sufficient Horizon, soil. A layer of soil, approximately parallel to quantity during one or more stages of secondary the surface, having distinct characteristics forest succession. produced by soil-forming processes. In the Green manure crop (agronomy). A soil-improving identification of soil horizons, an uppercase letter crop grown to be plowed under in an early stage represents the major horizons. Numbers or of maturity or soon after maturity. lowercase letters that follow represent Ground water. Water filling all the unblocked pores of subdivisions of the major horizons. An the material below the water table. explanation of the subdivisions is given in the Gully. A miniature valley with steep sides cut by “Soil Survey Manual” (Soil Survey Division Staff, running water and through which water ordinarily 1962). The major horizons of mineral soil are as runs only after rainfall. The distinction between a follows: gully and a rill is one of depth. A gully generally is O horizon.—An organic layer of fresh and an obstacle to farm machinery and is too deep to decaying plant residue. be obliterated by ordinary tillage; a rill is of lesser A horizon.—The mineral horizon at or near the depth and can be smoothed over by ordinary surface in which an accumulation of humified tillage. organic matter is mixed with the mineral material. Gypsum. A mineral consisting of hydrous calcium Also, a plowed surface horizon, most of which sulfate. was originally part of a B horizon. 260 Soil Survey
E horizon.—The mineral horizon in which the Illuviation. The movement of soil material from one main feature is loss of silicate clay, iron, horizon to another in the soil profile. Generally, aluminum, or some combination of these. material is removed from an upper horizon and B horizon.—The mineral horizon below an A or deposited in a lower horizon. E horizon. The B horizon is in part a layer of Impervious soil. A soil through which water, air, or transition from the overlying A to the underlying roots penetrate slowly or not at all. No soil is C horizon. The B horizon also has distinctive absolutely impervious to air and water all the characteristics, such as (1) accumulation of clay, time. sesquioxides, humus, or a combination of these; Increasers. Species in the climax vegetation that (2) prismatic or blocky structure; (3) redder or increase in amount as the more desirable plants browner colors than those in the A horizon; or are reduced by close grazing. Increasers (4) a combination of these. commonly are the shorter plants and the less C horizon.—The mineral horizon or layer, palatable to livestock. excluding indurated bedrock, that is little affected Infiltration. The downward entry of water into the by soil-forming processes and does not have the immediate surface of soil or other material, as properties typical of the overlying soil material. contrasted with percolation, which is movement The material of a C horizon may be either like or of water through soil layers or material. unlike that in which the solum formed. If the Infiltration capacity. The maximum rate at which material is known to differ from that in the solum, water can infiltrate into a soil under a given set of an Arabic numeral, commonly a 2, precedes the conditions. letter C. Infiltration rate. The rate at which water penetrates Cr horizon.—Sedimentary beds of consolidated the surface of the soil at any given instant, sandstone and semiconsolidated and usually expressed in inches per hour. The rate consolidated shale. Generally, roots can can be limited by the infiltration capacity of the penetrate this horizon only along fracture planes. soil or the rate at which water is applied at the R layer.—Consolidated bedrock beneath the soil. surface. The bedrock commonly underlies a C horizon, Intake rate. The average rate of water entering the but it can be directly below an A or a B horizon. soil under irrigation. Most soils have a fast initial Humus. The well-decomposed, more or less stable rate; the rate decreases with application time. part of the organic matter in mineral soils. Therefore, intake rate for design purposes is not Hydrologic soil groups. Refers to soils grouped a constant but is a variable depending on the net according to their runoff-producing irrigation application. The rate of water intake, in characteristics. The chief consideration is the inches per hour, is expressed as follows: inherent capacity of soil bare of vegetation to Less than 0.2 ...... very low permit infiltration. The slope and the kind of plant 0.2 to 0.4 ...... low cover are not considered but are separate factors 0.4 to 0.75 ...... moderately low in predicting runoff. Soils are assigned to four 0.75 to 1.25 ...... moderate groups. In group A are soils having a high 1.25 to 1.75 ...... moderately high infiltration rate when thoroughly wet and having a 1.75 to 2.5 ...... high low runoff potential. They are mainly deep, well More than 2.5 ...... very high drained, and sandy or gravelly. In group D, at the other extreme, are soils having a very slow Intermittent stream. A stream, or reach of a stream, infiltration rate and thus a high runoff potential. that flows for prolonged periods only when it They have a claypan or clay layer at or near the receives ground-water discharge or long, surface, have a permanent high water table, or continued contributions from melting snow or are shallow over nearly impervious bedrock or other surface and shallow subsurface sources. other material. A soil is assigned to two Invaders. On range, plants that encroach into an hydrologic groups if part of the acreage is area and grow after the climax vegetation has artificially drained and part is undrained. been reduced by grazing. Generally, plants Igneous rock. Rock formed by solidification from a invade following disturbance of the surface. molten or partially molten state. Major varieties Irrigation. Application of water to soils to assist in include plutonic and volcanic rock. Examples are production of crops. Methods of irrigation are: andesite, basalt, and granite. Powell County Area, Montana—Part I 261
Basin.—Water is applied rapidly to nearly level is composed chiefly of rock fragments derived plains surrounded by levees or dikes. from the valley walls by glacial abrasion and Border.—Water is applied at the upper end of a plucking or by mass wasting. strip in which the lateral flow of water is controlled Leaching. The removal of soluble material from soil by small earth ridges called border dikes, or or other material by percolating water. borders. Linear extensibility. Refers to the change in length Controlled flooding.—Water is released at of an unconfined clod as moisture content is intervals from closely spaced field ditches and decreased from a moist to a dry state. Linear distributed uniformly over the field. extensibility is used to determine the shrink-swell Corrugation.—Water is applied to small, closely potential of soils. It is an expression of the volume spaced furrows or ditches in fields of close- change between the water content of the clod at 1 1 growing crops or in orchards so that it flows in /3- or /10-bar tension (33kPa or 10kPa tension) only one direction. and oven dryness. Volume change is influenced Drip (or trickle).—Water is applied slowly and by the amount and type of clay minerals in the under low pressure to the surface of the soil or soil. The volume change is the percent change for into the soil through such applicators as emitters, the whole soil. If it is expressed as a fraction, the porous tubing, or perforated pipe. resulting value is COLE, coefficient of linear Furrow.—Water is applied in small ditches made extensibility. by cultivation implements. Furrows are used for Liquid limit. The moisture content at which the soil tree and row crops. passes from a plastic to a liquid state. Sprinkler.—Water is sprayed over the soil surface Loam. Soil material that is 7 to 27 percent clay through pipes or nozzles from a pressure system. particles, 28 to 50 percent silt particles, and less Subirrigation.—Water is applied in open ditches than 52 percent sand particles. or tile lines until the water table is raised enough Loamy soil. Coarse sandy loam, sandy loam, fine to wet the soil. sandy loam, very fine sandy loam, loam, silt Wild flooding.—Water, released at high points, is loam, silt, clay loam, sandy clay loam, or silty clay allowed to flow onto an area without controlled loam. distribution. Loess. Fine-grained material, dominantly of silt-sized
Ksat. Saturated hydraulic conductivity. (See particles, deposited by wind. Permeability.) Low-residue crops. Such crops as corn used for Kame. A moundlike hill of glacial drift, composed silage, peas, beans, and potatoes. Residue from chiefly of stratified sand and gravel. these crops is not adequate to control erosion Kame terrace. A terracelike ridge consisting of until the next crop in the rotation is established. stratified sand and gravel that were deposited by These crops return little organic matter to the soil. a meltwater stream flowing between a melting Low strength. The soil is not strong enough to glacier and a higher valley wall or lateral moraine support loads. and that remained after the disappearance of the Marl. An earthy, unconsolidated deposit consisting ice. It is commonly pitted with kettles and has an chiefly of calcium carbonate mixed with clay in irregular ice-contact slope. approximately equal amounts. Lacustrine deposit. Material deposited in lake water Masses. Concentrations of substances in the soil and exposed when the water level is lowered or matrix that do not have a clearly defined the elevation of the land is raised. boundary with the surrounding soil material and Lake plain. A surface marking the floor of an extinct cannot be removed as a discrete unit. Common lake, filled in by well-sorted, stratified sediments. compounds making up masses are calcium Landslide. The rapid downhill movement of a mass carbonate, gypsum or other soluble salts, iron of soil and loose rock, generally when wet or oxide, and manganese oxide. Masses consisting saturated. The speed and distance of movement, of iron oxide or manganese oxide generally are as well as the amount of soil and rock material, considered a type of redox concentration. vary greatly. Mean annual increment (MAI). The average annual Large stones (in tables). Rock fragments 3 inches increase in volume of a tree during its entire life. (7.6 centimeters) or more across. Large stones Mechanical treatment. Use of mechanical adversely affect the specified use of the soil. equipment for seeding, brush management, and Lateral moraine. A ridgelike moraine carried on and other management practices. deposited at the side margin of a valley glacier. It 262 Soil Survey
Medium textured soil. Very fine sandy loam, loam, sides. A mountain can occur as a single, isolated silt loam, or silt. mass or in a group forming a chain or range. Merchantable trees. Trees that are of sufficient size Muck. Dark, finely divided, well-decomposed organic to be economically processed into wood soil material. (See Sapric soil material.) products. Mudstone. Sedimentary rock formed by induration of Metamorphic rock. Rock of any origin altered in silt and clay in approximately equal amounts. mineralogical composition, chemical composition, Munsell notation. A designation of color by degrees or structure by heat, pressure, and movement. of three simple variables—hue, value, and Nearly all such rocks are crystalline. chroma. For example, a notation of 10YR 6/4 is Microhigh. An area that is 2 to 12 inches higher than a color with hue of 10YR, value of 6, and chroma the adjacent microlow. of 4. Microlow. An area that is 2 to 12 inches lower than Naturalized pasture. Forestland that is used the adjacent microhigh. primarily for the production of forage for grazing Mineral soil. Soil that is mainly mineral material and by livestock rather than for the production of low in organic material. Its bulk density is more wood products. Overstory trees are removed or than that of organic soil. managed to promote the native and introduced Minimum tillage. Only the tillage essential to crop understory vegetation occurring on the site. This production and prevention of soil damage. vegetation is managed for its forage value Miscellaneous area. An area that has little or no through the use of grazing management natural soil and supports little or no vegetation. principles. Miscellaneous water. A sewage lagoon, an Neutral soil. A soil having a pH value of 6.6 to 7.3. industrial waste pit, a fish hatchery, or a similar (See Reaction, soil.) water area. Nutrient, plant. Any element taken in by a plant Moderately coarse textured soil. Coarse sandy essential to its growth. Plant nutrients are mainly loam, sandy loam, or fine sandy loam. nitrogen, phosphorus, potassium, calcium, Moderately deep soil. A soil that is 20 to 40 inches magnesium, sulfur, iron, manganese, copper, deep over bedrock or to other material that boron, and zinc obtained from the soil and restricts the penetration of plant roots. carbon, hydrogen, and oxygen obtained from the Moderately fine textured soil. Clay loam, sandy clay air and water. loam, or silty clay loam. Observed rooting depth. Depth to which roots have Mollic epipedon. A thick, dark, humus-rich surface been observed to penetrate. horizon (or horizons) that has high base Organic matter. Plant and animal residue in the soil saturation and pedogenic soil structure. It may in various stages of decomposition. The content include the upper part of the subsoil. of organic matter in the surface layer is described Moraine. An accumulation of glacial drift in a as follows: topographic landform of its own, resulting chiefly from the direct action of glacial ice. Some types Very low ...... less than 0.5 percent are lateral, recessional, and terminal. Low ...... 0.5 to 1.0 percent Morphology, soil. The physical makeup of the soil, Moderately low ...... 1.0 to 2.0 percent including the texture, structure, porosity, Moderate ...... 2.0 to 4.0 percent consistence, color, and other physical, mineral, High ...... 4.0 to 8.0 percent and biological properties of the various horizons, Very high ...... more than 8.0 percent and the thickness and arrangement of those horizons in the soil profile. Outwash plain. An extensive area of glaciofluvial Mottling, soil. Areas of color that differ from the material that was deposited by meltwater matrix color. These colors are commonly streams. attributes retained from the geologic parent Overstory. The trees in a forest that form the upper material. (See Redox features for indications of crown cover. poor aeration and impeded drainage.) Oxbow. The horseshoe-shaped channel of a former Mountain. A natural elevation of the land surface, meander, remaining after the stream formed a rising more than 1,000 feet above surrounding cutoff across a narrow meander neck. lowlands, commonly of restricted summit area Pan. A compact, dense layer in a soil that impedes (relative to a plateau) and generally having steep the movement of water and the growth of roots. Powell County Area, Montana—Part I 263
For example, hardpan, fragipan, claypan, Ponding. Standing water on soils in closed plowpan, and traffic pan. depressions. Unless the soils are artificially Parent material. The unconsolidated organic and drained, the water can be removed only by mineral material in which soil forms. percolation or evapotranspiration. Peat. Unconsolidated material, largely Poor filter (in tables). Because of rapid permeability undecomposed organic matter, that has or an impermeable layer near the surface, the soil accumulated under excess moisture. (See Fibric may not adequately filter effluent from a waste soil material.) disposal system. Ped. An individual natural soil aggregate, such as a Poorly graded. Refers to a coarse-grained soil or soil granule, a prism, or a block. material consisting mainly of particles of nearly Pedon. The smallest volume that can be called the same size. Because there is little difference in “a soil.” A pedon is three dimensional and large size of the particles, density can be increased enough to permit study of all horizons. Its only slightly by compaction. area ranges from about 10 to 100 square feet Potential natural community (PNC). The biotic (1 square meter to 10 square meters), depending community that would become established on an on the variability of the soil. ecological site if all successional sequences were Percolation. The movement of water through the soil. completed without interferences by man under Percs slowly (in tables). The slow movement of water the present environmental conditions. Natural through the soil, adversely affecting the specified disturbances are inherent in its development. The use. PNC may include acclimatized or naturalized Permeability. The quality of the soil that enables nonnative species. water or air to move downward through the Potential rooting depth (effective rooting depth). profile. Depth to which roots could penetrate if the Terms describing permeability are: content of moisture in the soil were adequate. The soil has no properties restricting the Very slow ...... less than 0.06 inch penetration of roots to this depth. Slow ...... 0.06 to 0.2 inch Prescribed burning. The application of fire to land Moderately slow ...... 0.2 to 0.6 inch under such conditions of weather, soil moisture, Moderate ...... 0.6 to 2.0 inches and time of day as presumably will result in the Moderately rapid ...... 2.0 to 6.0 inches intensity of heat and spread required to Rapid ...... 6.0 to 20 inches accomplish specific forest management, wildlife, Very rapid ...... more than 20 inches grazing, or fire hazard reduction purposes. Productivity, soil. The capability of a soil for pH value. A numerical designation of acidity and producing a specified plant or sequence of plants alkalinity in soil. (See Reaction, soil.) under specific management. Phase, soil. A subdivision of a soil series based on Profile, soil. A vertical section of the soil extending features that affect its use and management, through all its horizons and into the parent such as slope, stoniness, and flooding. material. Piping (in tables). Formation of subsurface tunnels or Proper grazing use. Grazing at an intensity that pipelike cavities by water moving through the soil. maintains enough cover to protect the soil and Plastic limit. The moisture content at which a soil maintain or improve the quantity and quality of changes from semisolid to plastic. the desirable vegetation. This practice increases Plasticity index. The numerical difference between the vigor and reproduction capacity of the key the liquid limit and the plastic limit. The range of plants and promotes the accumulation of litter moisture content within which the soil remains and mulch necessary to conserve soil and plastic. water. Playa. The generally dry and nearly level lake plain Quartzite, metamorphic. Rock consisting mainly of that occupies the lowest parts of closed quartz that formed through recrystallization of depressional areas, such as those on quartz-rich sandstone or chert. intermontane basin floors. Temporary flooding Quartzite, sedimentary. Very hard but occurs primarily in response to precipitation and unmetamorphosed sandstone consisting chiefly runoff. of quartz grains. Plowpan. A compacted layer formed in the soil Range condition. The present composition of the directly below the plowed layer. plant community on a range site in relation to the 264 Soil Survey
potential natural plant community for that site. change in hue or chroma within 30 minutes after (See Similarity index.) exposure to air as the iron is oxidized (Fe III). A Range site. (See Ecological site.) type of redox feature. Rangeland. Land on which the potential natural Regeneration. The new growth of a natural plant vegetation is predominantly grasses, grasslike community, developing from seed. plants, forbs, or shrubs suitable for grazing or Regolith. The unconsolidated mantle of weathered browsing. It includes natural grasslands, rock and soil material on the earth’s surface; the savannas, many wetlands, some deserts, loose earth material above the solid rock. tundras, and areas that support certain forb and Relict stream terrace. One of a series of platforms shrub communities. in or adjacent to a stream valley that formed prior Reaction, soil. A measure of acidity or alkalinity of a to the current stream system. soil, expressed in pH values. A soil that tests to Relief. The elevations or inequalities of a land pH 7.0 is described as precisely neutral in surface, considered collectively. reaction because it is neither acid nor alkaline. Residuum (residual soil material). Unconsolidated, The degrees of acidity or alkalinity, expressed as weathered or partly weathered mineral material pH values, are: that accumulated as consolidated rock Ultra acid ...... less than 3.5 disintegrated in place. Extremely acid ...... 3.5 to 4.4 Rill. A steep-sided channel resulting from accelerated Very strongly acid ...... 4.5 to 5.0 erosion. A rill generally is a few inches deep and Strongly acid ...... 5.1 to 5.5 not wide enough to be an obstacle to farm Moderately acid ...... 5.6 to 6.0 machinery. Slightly acid ...... 6.1 to 6.5 Riser. The relatively short, steeply sloping area below Neutral ...... 6.6 to 7.3 a terrace tread that grades to a lower terrace Slightly alkaline ...... 7.4 to 7.8 tread or base level. Moderately alkaline ...... 7.9 to 8.4 Riverwash. Unstable areas of sandy, silty, clayey, or Strongly alkaline ...... 8.5 to 9.0 gravelly sediments. These areas are flooded, Very strongly alkaline ...... 9.1 and higher washed, and reworked by rivers so frequently that they support little or no vegetation. Recessional moraine. A moraine formed during a Road cut. A sloping surface produced by mechanical temporary but significant halt in the retreat of a means during road construction. It is commonly glacier. on the uphill side of the road. Red beds. Sedimentary strata that are mainly red Rock fragments. Rock or mineral fragments having and are made up largely of sandstone and shale. a diameter of 2 millimeters or more; for example, Redox concentrations. Nodules, concretions, soft boulders, stones, cobbles, and gravel masses, pore linings, and other features resulting Rock outcrop. Exposures of bare bedrock other than from the accumulation of iron or manganese lava flows and rock-lined pits. oxide. An indication of chemical reduction and Root zone. The part of the soil that can be oxidation resulting from saturation. penetrated by plant roots. Redox depletions. Low-chroma zones from which Rooting depth (in tables). Shallow root zone. The iron and manganese oxide or a combination of soil is shallow over a layer that greatly restricts iron and manganese oxide and clay has been roots. removed. These zones are indications of the Rubble land. Areas that have more than 90 percent chemical reduction of iron resulting from of the surface covered by stones or boulders. saturation. Voids contain no soil material and virtually no Redox features. Redox concentrations, redox vegetation other than lichens. The areas depletions, reduced matrices, a positive reaction commonly are at the base of mountain slopes, to alpha,alpha-dipyridyl, and other features but some are on mountain slopes as deposits of indicating the chemical reduction and oxidation of cobbles, stones, and boulders left by Pleistocene iron and manganese compounds resulting from glaciation or by periglacial phenomena. saturation. Runoff. The precipitation discharged into stream Reduced matrix. A soil matrix that has low chroma in channels from an area. The water that flows off situ because of chemically reduced iron (Fe II). the surface of the land without sinking into the The chemical reduction results from nearly soil is called surface runoff. Water that enters the continuous wetness. The matrix undergoes a soil before reaching surface streams is called Powell County Area, Montana—Part I 265
ground-water runoff or seepage flow from ground They are higher on the landscape than the flood water. plain. Saline soil. A soil containing soluble salts in an Seepage (in tables). The movement of water through amount that impairs growth of plants. A saline soil soil. Seepage adversely affects the specified use. does not contain excess exchangeable sodium. Semiconsolidated sedimentary beds. Soft geologic Salinity. The electrical conductivity of a saline soil. It sediments that disperse when fragments are is expressed, in millimhos per centimeter, as placed in water. The fragments are hard or very follows: hard when dry. Determining the texture by the Nonsaline ...... 0 to 4 usual field method is difficult. Slightly saline ...... 4 to 8 Sequum. A sequence consisting of an illuvial horizon Moderately saline ...... 8 to 16 and the overlying eluvial horizon. (See Strongly saline ...... more than 16 Eluviation.) Series, soil. A group of soils that have profiles that Sand. As a soil separate, individual rock or mineral are almost alike, except for differences in texture fragments from 0.05 to 2.0 millimeters in of the surface layer or of the underlying material. diameter. Most sand grains consist of quartz. As All the soils of a series have horizons that are a soil textural class, a soil that is 85 percent or similar in composition, thickness, and more sand and not more than 10 percent clay. arrangement. Sandstone. Sedimentary rock containing dominantly Shale. Sedimentary rock formed by the hardening of sand-sized particles. a clay deposit. Sandy soil. Sand or loamy sand. Shallow soil. A soil that is 10 to 20 inches deep over Sapric soil material (muck). The most highly bedrock or to other material that restricts the decomposed of all organic soil material. Muck penetration of plant roots. has the least amount of plant fiber, the highest Sheet erosion. The removal of a fairly uniform layer bulk density, and the lowest water content at of soil material from the land surface by the saturation of all organic soil material. action of rainfall and surface runoff. Saturation. Wetness characterized by zero or Shelterwood system. A forest management system positive pressure of the soil water. Under requiring the removal of a stand in a series of conditions of saturation, the water will flow from cuts so that regeneration occurs under a partial the soil matrix into an unlined auger hole. canopy. After regeneration, a final cut removes Sawlogs. Logs of suitable size and quality for the the shelterwood and allows the stand to develop production of lumber. in the open as an even-aged stand. The system is Scarification. The act of abrading, scratching, well suited to sites where shelter is needed for loosening, crushing, or modifying the surface to regeneration, and it can aid regeneration of the increase water absorption or to provide a more more intolerant tree species in a stand. tillable soil. Shoulder. The uppermost inclined surface at the top Scribner’s log rule. A method of estimating the of a hillside. It is the transitional zone from the number of board feet that can be cut from a log of backslope to the summit of a hill or mountain. The a given diameter and length. surface is dominantly convex in profile and Sedimentary plain. An extensive nearly level to erosional in origin. gently rolling or moderately sloping area that is Shrink-swell (in tables). The shrinking of soil when underlain by sedimentary bedrock and that has a dry and the swelling when wet. Shrinking and slope of 0 to 8 percent. swelling can damage roads, dams, building Sedimentary rock. Rock made up of particles foundations, and other structures. It can also deposited from suspension in water. The chief damage plant roots. kinds of sedimentary rock are conglomerate, Side slope. A geomorphic component of hills formed from gravel; sandstone, formed from consisting of a laterally planar area of a hillside. sand; shale, formed from clay; and limestone, The overland waterflow is predominantly parallel. formed from soft masses of calcium carbonate. Silica. A combination of silicon and oxygen. The There are many intermediate types. Some wind- mineral form is called quartz. deposited sand is consolidated into sandstone. Silt. As a soil separate, individual mineral particles Sedimentary uplands. Land areas of bedrock that range in diameter from the upper limit of clay formed from water- or wind-deposited sediments. (0.002 millimeters) to the lower limit of very fine 266 Soil Survey
sand (0.05 millimeters). As a soil textural class, surfaces on the steeper slopes; on faces of soil that is 80 percent or more silt and less than blocks, prisms, and columns; and in swelling 12 percent clay. clayey soils, where there is marked change in Siltstone. Sedimentary rock made up of dominantly moisture content. silt-sized particles. Slickspot. A small area of soil having a puddled, Similar soils. Soils that share limits of diagnostic crusted, or smooth surface and an excess of criteria, behave and perform in a similar manner, exchangeable sodium. The soil generally is loamy and have similar conservation needs or or clayey, is slippery when wet, and is low in management requirements for the major land productivity. uses in the survey area. Slope. The inclination of the land surface from the Similarity index. A similarity index is the percentage horizontal. Percentage of slope is the vertical of a specific vegetation state plant community distance divided by horizontal distance, then that is presently on the site. multiplied by 100. Thus, a slope of 20 percent is a Sinkhole. A depression in the landscape where drop of 20 feet in 100 feet of horizontal distance. limestone has been dissolved. In this survey, the following slope classes are Site class. A grouping of site indexes into five to recognized: seven production capability levels. Each level can Nearly level ...... 0 to 2 percent be represented by a site curve. Gently sloping ...... 2 to 4 percent Site curve (50-year). A set of related curves on a Moderately sloping ...... 4 to 8 percent graph that shows the average height of dominant Strongly sloping ...... 8 to 15 percent or dominant and codominant trees for the range Moderately steep ...... 15 to 25 percent of ages on soils that differ in productivity. Each Steep ...... 25 to 45 percent level is represented by a curve. The basis of the Very steep ...... more than 45 percent curves is the height of dominant or dominant and codominant trees that are 50 years old or are 50 Slope (in tables). Slope is great enough that special years old at breast height. practices are required to ensure satisfactory Site curve (100-year). A set of related curves on a performance of the soil for a specific use. graph that shows the average height of dominant Slow refill (in tables). The slow filling of ponds, or dominant and codominant trees for a range of resulting from restricted permeability in the soil. ages on soils that differ in productivity. Each level Small stones (in tables). Rock fragments less than 3 is represented by a curve. The basis of the curves inches (7.6 centimeters) in diameter. Small is the height of dominant or dominant and stones adversely affect the specified use of the codominant trees that are 100 years old or are soil. 100 years old at breast height. Sodic (alkali) soil. A soil having so high a degree of Site index. A designation of the quality of a forest site alkalinity (pH 8.5 or higher) or so high a based on the height of the dominant stand at an percentage of exchangeable sodium (15 percent arbitrarily chosen age. For example, if the or more of the total exchangeable bases), or average height attained by dominant or dominant both, that plant growth is restricted. and codominant trees in a fully stocked stand at Sodicity. The degree to which a soil is affected by the age of 50 years is 75 feet, the site index is 75. exchangeable sodium. Sodicity is expressed as a Skid trails. Pathways along which logs are dragged sodium adsorption ratio (SAR) of a saturation to a common site for loading onto a logging truck. extract, or the ratio of Na+ to Ca++ + Mg++. The Slash. The branches, bark, treetops, reject logs, and degrees of sodicity and their respective ratios broken or uprooted trees left on the ground after are: logging. Slight ...... less than 13:1 Slickens. Accumulations of fine textured material, Moderate ...... 13-30:1 such as material separated in placer-mine and Strong ...... more than 30:1 ore-mill operations. Slickens from ore mills commonly consist of freshly ground rock that has Sodium adsorption ratio (SAR). A measure of the undergone chemical treatment during the milling amount of sodium (Na) relative to calcium (Ca) process. and magnesium (Mg) in the water extract from Slickensides. Polished and grooved surfaces saturated soil paste. It is the ratio of the Na produced by one mass sliding past another. In concentration divided by the square root of one- soils, slickensides may occur at the bases of slip half of the Ca + Mg concentration. Powell County Area, Montana—Part I 267
Soft bedrock. Bedrock that can be excavated with Stream channel. The hollow bed where a natural trenching machines, backhoes, small rippers, and stream of surface water flows or may flow; the other equipment commonly used in construction. deepest or central part of the bed, formed by the Soil. A natural, three-dimensional body at the earth’s main current and covered more or less surface. It is capable of supporting plants and has continuously by water. properties resulting from the integrated effect of Stream terrace. One of a series of platforms in a climate and living matter acting on earthy parent stream valley, flanking and more or less parallel material, as conditioned by relief over periods of to the stream channel. It originally formed near time. the level of the stream and is the dissected Soil separates. Mineral particles less than 2 remnants of an abandoned flood plain, millimeters in equivalent diameter and ranging streambed, or valley floor that were produced between specified size limits. The names and during a former stage of erosion or deposition. sizes, in millimeters, of separates recognized in Stripcropping. Growing crops in a systematic the United States are as follows: arrangement of strips or bands that provide Very coarse sand ...... 2.0 to 1.0 vegetative barriers to soil blowing and water Coarse sand ...... 1.0 to 0.5 erosion. Medium sand ...... 0.5 to 0.25 Structure, soil. The arrangement of primary soil Fine sand ...... 0.25 to 0.10 particles into compound particles or aggregates. Very fine sand ...... 0.10 to 0.05 The principal forms of soil structure are platy Silt ...... 0.05 to 0.002 (laminated), prismatic (vertical axis of aggregates Clay ...... less than 0.002 longer than horizontal), columnar (prisms with rounded tops), blocky (angular or subangular), Solum. The upper part of a soil profile, above the C and granular. Structureless soils are either single horizon, in which the processes of soil formation grain (each grain by itself, as in dune sand) or are active. The solum in soil consists of the A, E, massive (the particles adhering without any and B horizons. Generally, the characteristics of regular cleavage, as in many hardpans). the material in these horizons are unlike those of Stubble mulch. Stubble or other crop residue left on the material below the solum. The living roots and the soil or partly worked into the soil. It protects plant and animal activities are largely confined to the soil from wind erosion and water erosion after the solum. harvest, during preparation of a seedbed for the Species. A single, distinct kind of plant or animal next crop, and during the early growing period of having certain distinguishing characteristics. the new crop. Stone line. A concentration of coarse fragments in a Subsoil. Technically, the B horizon; roughly, the part soil. Generally, it is indicative of an old weathered of the solum below plow depth. surface. In a cross section, the line may be one Subsoiling. Tilling a soil below normal plow depth, fragment or more thick. It generally overlies ordinarily to shatter or loosen a layer that is material that weathered in place and is overlain restrictive to roots. by recent sediment of variable thickness. Substratum. The part of the soil below the solum. Stones. Rock fragments 10 to 24 inches (25 to 60 Subsurface layer. Any surface soil horizon (A, E, AB, centimeters) in diameter if rounded or 15 to 24 or EB) below the surface layer. inches (38 to 60 centimeters) in length if flat. Summer fallow. The tillage of uncropped land during Stony. Refers to a soil containing stones in numbers the summer to control weeds and allow storage that interfere with tillage, or stones cover .01 to of moisture in the soil for the growth of a later 0.1 percent of the surface. Very stony means that crop. A practice common in semiarid regions, 0.1 to 3.0 percent of the surface is covered with where annual precipitation is not enough to stones. Extremely stony means that 3 to 15 produce a crop every year. Summer fallow is percent of the surface is covered with stones. frequently practiced before planting winter grain. Stony soil material. Soil that is 15 to 35 percent, by Summit. A general term for the top, or highest level, volume, rock fragments that are dominated by of an upland feature, such as a hill or mountain. It fragments 10 to 24 inches (25 to 60 centimeters) commonly refers to a higher area that has a in diameter. gentle slope and is flanked by steeper slopes. Strath terrace. A surface cut formed by the erosion Surface layer. The soil ordinarily moved in tillage, or of hard or semiconsolidated bedrock and thinly its equivalent in uncultivated soil, ranging in mantled with stream deposits. depth from 4 to 10 inches (10 to 25 centimeters). 268 Soil Survey
Frequently designated as the “plow layer,” or the Tilth, soil. The physical condition of the soil as “Ap horizon.” related to tillage, seedbed preparation, seedling Tailwater. The water directly downstream of a emergence, and root penetration. structure. Toeslope. The outermost inclined surface at the base Talus. Rock fragments of any size or shape, of a hill. Toeslopes are commonly gentle and commonly coarse and angular, derived from and linear in profile. lying at the base of a cliff or very steep rock Too arid (in tables). The soil is dry most of the time, slope. The accumulated mass of such loose, and vegetation is difficult to establish. broken rock formed chiefly by falling, rolling, or Topsoil. The upper part of the soil, which is the most sliding. favorable material for plant growth. It is ordinarily Taxadjuncts. Soils that cannot be classified in a rich in organic matter and is used to topdress series recognized in the classification system. roadbanks, lawns, and land affected by mining. Such soils are named for a series they strongly Trace elements. Chemical elements, for example, resemble and are designated as taxadjuncts to zinc, cobalt, manganese, copper, and iron, in that series because they differ in ways too small soils in extremely small amounts. They are to be of consequence in interpreting their use essential to plant growth. and behavior. Trafficability. The degree to which a soil is capable Terminal moraine. A belt of thick glacial drift that of supporting vehicular traffic across a wide generally marks the termination of important range in soil moisture conditions. glacial advances. Tread. The relatively flat terrace surface that was cut Terrace. An embankment, or ridge, constructed or built by stream or wave action. across sloping soils on the contour or at a slight Tuff. A compacted deposit that is 50 percent or more angle to the contour. The terrace intercepts volcanic ash and dust. surface runoff so that water soaks into the soil or Understory. Any plants in a forest community that flows slowly to a prepared outlet. A terrace in a grow to a height of less than 5 feet. field generally is built so that the field can be Upland. Land at a higher elevation, in general, than farmed. A terrace intended mainly for drainage the alluvial plain or stream terrace; land above has a deep channel that is maintained in the lowlands along streams. permanent sod. Valley. An elongated depressional area primarily Terrace (geologic). An old alluvial plain, ordinarily flat developed by stream action. or undulating, bordering a river, a lake, or the Valley fill. In glaciated regions, material deposited in sea. stream valleys by glacial meltwater. In Terracette. Small, irregular step-like forms on steep nonglaciated regions, alluvium deposited by hillslopes, especially in pasture, formed by creep heavily loaded streams. or erosion of surficial materials that may or may Variegation. Refers to patterns of contrasting colors not be induced by trampling of livestock such as assumed to be inherited from the parent material sheep or cattle. rather than to be the result of poor drainage. Texture, soil. The relative proportions of sand, silt, Varve. A sedimentary layer or a lamina or sequence and clay particles in a mass of soil. The basic of laminae deposited in a body of still water within textural classes, in order of increasing proportion a year. Specifically, a thin pair of graded of fine particles, are sand, loamy sand, sandy glaciolacustrine layers seasonally deposited, loam, loam, silt loam, silt, sandy clay loam, clay usually by meltwater streams, in a glacial lake or loam, silty clay loam, sandy clay, silty clay, and other body of still water in front of a glacier. clay. The sand, loamy sand, and sandy loam Very deep soil. A soil that is more than 60 inches classes may be further divided by specifying deep over bedrock or to other material that “coarse,” “fine,” or “very fine.” restricts the penetration of plant roots. Thin layer (in tables). A layer of otherwise suitable Very shallow soil. A soil that is less than 10 inches soil material that is too thin for the specified use. deep over bedrock or to other material that Till plain. An extensive, nearly level to gently rolling restricts the penetration of plant roots. or moderately sloping area that is underlain by Water bars. Smooth, shallow ditches or depressional or consists of till and that has a slope of 0 to areas that are excavated at an angle across a 8 percent. sloping road. They are used to reduce the Powell County Area, Montana—Part I 269
downward velocity of water and divert it off Well graded. Refers to soil material consisting of and away from the road surface. Water bars coarse-grained particles that are well distributed can easily be driven over if constructed over wide range in size or diameter. Such soil properly. normally can be easily increased in density and Water-spreading. Diverting runoff from natural bearing properties by compaction. Contrasts with channels by means of a system of dams, dikes, poorly graded soil. or ditches and spreading it over relatively flat Wilting point (or permanent wilting point). The surfaces. moisture content of soil, on an ovendry basis, at Weathering. All physical and chemical changes which a plant (specifically a sunflower) wilts so produced in rocks or other deposits at or near the much that it does not recover when placed in a earth’s surface by atmospheric agents. These humid, dark chamber. changes result in disintegration and Windthrow. The action of uprooting and tipping over decomposition of the material. trees by the wind. Accessibility Statement
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