United States In cooperation with Department of United States Department Agriculture of the Interior, Bureau of Soil Survey of Land Management; Natural University of Idaho, Jerome County Resources College of Agriculture; and Conservation Idaho Soil Conservation Service Commission and Part of Twin Falls County, Idaho

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How to Use This Soil Survey

General Soil Map

The general soil map, which is the color map preceding the detailed soil maps, shows the survey area divided into groups of associated soils called general soil map units. This map is useful in planning the use and management of large areas.

To find information about your area of interest, locate that area on the map, identify the name of the map unit in the area on the color-coded map legend, then refer to the section General Soil Map Units for a general description of the soils in your area.

Detailed Soil Maps

The detailed soil maps follow the general soil map. These maps can be useful in planning the use and management of small areas.

To find information about your area of interest, locate that area on the Index to Map Sheets, which precedes the soil maps. Note the number of the map sheet and turn to that sheet.

Locate your area of interest on the map sheet. Note the map units symbols that are in that area. Turn to the Contents, which lists the map units by symbol and name and shows the page where each map unit is described.

The Contents shows which table has data on a specific land use for each detailed soil map unit. Also see the Contents for sections of this publication that may address your specific needs. 4

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 1991. 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 United States Department of the Interior, Bureau of Land Management; the University of Idaho, College of Agriculture; and the Idaho Soil Conservation Commission. The survey is part of the technical assistance furnished to the Balanced Rock, Twin Falls, and North Side Soil Conservation Districts and the Snake River Soil and Water Conservation District. Since the publication of this survey, more information on soil properties may have been collected, new interpretations developed, or existing interpretive criteria modified. The most current soil information and interpretations for this survey are in the Field Office Technical Guide (FOTG) at the local Natural Resources Conservation Service field office. The soil maps in this publication may exist in digital form in a full quadrangle format. The digitizing of the maps is in accordance with the Soil Survey Geographic (SSURGO) database standards. During the digitizing process, changes or corrections to the maps may have occurred. These changes or corrections improve the matching of this survey to adjacent surveys and correct previous errors or omissions of map unit symbols or lines. If digital SSURGO certified maps exist for this survey, they are considered the official maps for the survey area and are part of the FOTG at the local Natural Resources Conservation Service field office. 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 U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, gender, religion, age, disability, political beliefs, sexual orientation, or 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 USDA’s TARGET Center at (202) 720-2600 (voice and 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 and TDD). USDA is an equal opportunity provider and employer.

Cover: Irrigated soils in the survey area. The Snake River Canyon separates Jerome County in foreground and Twin Falls County in background.

Additional information about the Nation’s natural resources is available on the Natural Resources Conservation Service home page on the World Wide Web. The address is http://www.nrcs.usda.gov (click on “Technical Resources”). 5

Contents

Cover ...... 1 8—Arness sandy loam, 2 to 6 percent How to Use This Soil Survey ...... 3 slopes ...... 32 Contents ...... 5 9—Badlands-Kudlac association, 30 to 90 Foreword ...... 11 percent slopes ...... 33 General Nature of the Survey Area ...... 14 10—Bahem silt loam, 1 to 4 percent History and Development ...... 14 slopes ...... 33 Water Supply ...... 14 11—Bahem silt loam, 4 to 8 percent Agriculture ...... 14 slopes ...... 34 Climate ...... 15 12—Bahem silt loam, 8 to 12 percent How This Survey Was Made ...... 16 slopes ...... 35 General Soil Map Units ...... 19 13—Banbury loam, 2 to 12 percent slopes .... 35 Soil Descriptions ...... 19 14—Banbury loam, 12 to 20 percent 1. Purdam-Rakane-Blacknest ...... 19 slopes ...... 36 2. Portneuf ...... 19 15—Banbury-Rock outcrop complex, 2 to 3. Sluka-Minveno ...... 20 20 percent slopes ...... 37 4. Power-McCain-Paulville ...... 20 16—Bancy-Tanner complex, 2 to 12 5. Kecko-Taunton-Harsan ...... 20 percent slopes ...... 38 6. Rock outcrop-Banbury-Paulville...... 21 17—Barrymore silt loam, 1 to 4 percent 7. Chuska-Colthorp ...... 21 slopes ...... 38 8. Roseworth ...... 21 18—Barrymore-Starbuck complex, 1 to 9. Lud-Elijah-Pigtail ...... 21 4 percent slopes ...... 39 10. Chiara ...... 21 19—Bluegulch gravelly loam, 2 to 12 11. Windypoint-Arbidge ...... 21 percent slopes ...... 40 12. Ackett ...... 22 20—Bluegulch-Rock outcrop complex, 2 13. Rock outcrop-Xerorthents...... 22 to 30 percent slopes ...... 41 14. Tanner-Budlewis-Arness ...... 22 21—Brose-Amboat complex, 2 to 20 15. Oshone-Aninto-Tock ...... 22 percent slopes ...... 41 16. Brose-Amboat-Ragpie ...... 23 22—Budlewis cobbly silt loam, 2 to 17. Keman-Dehana-Rutherford...... 23 6 percent slopes ...... 42 18. Doodlelink-Stricker-Nawt ...... 23 23—Budlewis-Chayson complex, 2 to 19. Eep-Mug-Player ...... 23 6 percent slopes ...... 43 Detailed Soil Map Units ...... 25 24—Budlewis-Tanner complex, 2 to Soil Descriptions ...... 27 6 percent slopes ...... 44 1—Ackett extremely gravelly clay loam, 25—Chiara silt loam, 1 to 8 percent slopes .... 45 2 to 10 percent slopes ...... 27 26—Chuska loam, 1 to 10 percent slopes...... 45 2—Ackett extremely gravelly clay loam, 27—Chuska gravelly loam, 2 to 12 percent 10 to 25 percent slopes ...... 28 slopes ...... 46 3—Aeric Fluvaquents ...... 29 28—Chuska very stony loam, 2 to 12 4—Aninto gravelly loam, 1 to 6 percent slopes ...... 47 percent slopes ...... 29 29—Colthorp cobbly silt loam, 1 to 4 5—Aninto complex, 10 to 30 percent slope .... 30 percent slopes ...... 48 6—Antelope Springs loam, 0 to 4 percent 30—Colthorp very cobbly silt loam, 1 to 15 slopes ...... 31 percent slopes ...... 49 7—Arbidge sandy loam, 1 to 4 percent 31—Congle gravelly loam, 8 to 30 slopes ...... 31 percent slopes ...... 49 6

32—Dehana-Rock outcrop complex, 4 55—Iwica-Budlewis complex, 2 to 6 to 40 percent slopes ...... 50 percent slopes ...... 66 33—Dolman silt loam, 1 to 4 percent 56—Jestrick-Kecko complex, 1 to 8 slopes ...... 50 percent slopes ...... 67 34—Doodlelink very gravelly loam, 8 to 57—Kavon very gravelly loam, 5 to 30 percent slopes ...... 51 35 percent slopes ...... 68 35—Doodlelink very gravelly loam, 30 58—Kecko fine sandy loam, 1 to 4 percent to 75 percent slopes ...... 52 slopes ...... 69 36—Eep very cobbly sandy loam, 6 to 35 59—Kecko fine sandy loam, 4 to 8 percent percent slopes ...... 52 slopes ...... 69 37—Eep-Dehana-Rock outcrop 60—Kecko-Emberton complex, 1 to association, 6 to 40 percent slopes ...... 53 6 percent slopes ...... 70 38—Eep-Dehana-Rock outcrop 61—Keman very gravelly loam, 2 to association, 40 to 75 percent slopes ..... 54 35 percent slopes ...... 71 39—Elhina very gravelly loam, 2 to 6 62—Kudlac silty clay, 4 to 30 percent percent slopes ...... 55 slopes ...... 72 40—Elijah silt loam, 2 to 4 percent 63—Lankbush loamy sand, 2 to 10 slopes ...... 56 percent slopes ...... 72 41—Elijah-Pigtail complex, 1 to 6 percent 64—Lud silt loam, 2 to 10 percent slopes ...... 73 slopes ...... 56 65—Lud very cobbly silt loam, 2 to 42—Fathom loamy fine sand, 0 to 12 10 percent slopes ...... 74 percent slopes ...... 57 66—Mackey very gravelly loam, 8 to 43—Fathom loamy fine sand, 30 to 30 percent slopes ...... 74 60 percent slopes ...... 58 67—Minidoka silt loam, 0 to 2 percent 44—Fathom bouldery loamy fine sand, slopes ...... 75 2 to 20 percent slopes ...... 58 68—Minidoka silt loam, 2 to 4 percent 45—Forvic silty clay loam, 2 to 6 percent slopes ...... 76 slopes ...... 59 69—Minveno silt loam, 0 to 2 percent 46—Gosinta silt loam, 0 to 2 percent slopes ...... 76 slopes ...... 60 70—Minveno silt loam, 2 to 8 percent 47—Harsan fine sandy loam, 1 to 4 slopes ...... 77 percent slopes ...... 60 71—Minveno very stony silt loam, 2 to 20 48—Harsan-Sidlake-Quincy complex, 1 percent slopes ...... 78 to 8 percent slopes ...... 61 72—Mug very cobbly loam, 2 to 10 percent 49—Hogmalat-Rock outcrop complex, slopes ...... 78 3 to 40 percent slopes ...... 62 73—Oshone clay loam, 2 to 8 percent 50—Hoosegow-Sidlake-Rock outcrop slopes ...... 79 complex, 2 to 15 percent slopes ...... 63 74—Oshone complex, 2 to 10 percent 51—Howcree-Ibola complex, 2 to 6 percent slopes ...... 80 slopes ...... 64 75—Owsel silt loam, 0 to 2 percent slopes .... 80 52—Hutton mucky peat, 0 to 2 percent 76—Owsel silt loam, 2 to 4 percent slopes .... 81 slopes ...... 65 77—Owsel silt loam, 4 to 8 percent 53—Isknat loam, 2 to 8 percent slopes ...... 65 slopes ...... 82 54—Isknat gravelly loam, 3 to 15 percent 78—Owsel silt loam, 8 to 12 percent slopes ...... 66 slopes ...... 82 7

79—Owsel silt loam, 12 to 20 percent 105—Rakane-Blacknest complex, 4 to slopes ...... 83 8 percent slopes ...... 101 80—Paniogue loam, 0 to 2 percent slopes ..... 84 106—Rakane-Blacknest complex, 8 81—Paniogue loam, 2 to 4 percent slopes ..... 84 to 15 percent slopes ...... 102 82—Paulville silt loam, 0 to 2 percent 107—Rock outcrop-Banbury-Paulville slopes ...... 85 complex, 2 to 6 percent slopes ...... 103 83—Paulville-Idow complex, 1 to 4 108—Rock outcrop-Xerorthents complex, percent slopes ...... 85 very steep...... 104 84—Pits, gravel ...... 86 109—Roseworth silt loam, 1 to 8 percent 85—Player-Rock outcrop complex, 30 slopes ...... 105 to 75 percent slopes ...... 86 110—Roseworth cobbly silt loam, 1 to 86—Portneuf silt loam, 0 to 2 percent 8 percent slopes ...... 106 slopes ...... 88 111—Roza loam, 0 to 1 percent slopes ...... 106 87—Portneuf silt loam, 2 to 4 percent 112—Ruclick very gravelly loam, 5 to slopes ...... 88 30 percent slopes ...... 107 88—Portneuf silt loam, 4 to 8 percent 113—Rutherford extremely gravelly loam, slopes ...... 89 2 to 20 percent slopes ...... 108 89—Portneuf silt loam, 8 to 12 percent 114—Schnipper silt loam, 2 to 6 percent slopes ...... 90 slopes ...... 108 90—Power silt loam, 1 to 4 percent slopes .... 91 115—Schnipper silt loam, 6 to 12 91—Power-McCain complex, 1 to 6 percent slopes ...... 109 percent slopes ...... 91 116—Schnipper-Rogerson complex, 2 92—Power-Owinza-Rock outcrop complex, to 12 percent slopes ...... 109 1 to 8 percent slopes ...... 92 117—Scoon fine sandy loam, 1 to 4 93—Purdam silt loam, 1 to 4 percent percent slopes ...... 110 slopes ...... 93 118—Scoon loam, 0 to 2 percent 94—Purdam silt loam, 4 to 8 percent slopes ...... 111 slopes ...... 94 119—Scoon loam, 2 to 4 percent slopes...... 111 95—Purdam silt loam, 8 to 12 percent 120—Shabliss silt loam, 1 to 4 percent slopes ...... 95 slopes ...... 112 96—Quincy loamy fine sand, 2 to 20 121—Shabliss silt loam, 4 to 8 percent percent slopes ...... 95 slopes ...... 113 97—Quincy-Kecko complex, 1 to 6 122—Shano silt loam, 1 to 4 percent percent slopes ...... 96 slopes ...... 114 98—Rad silt loam, 0 to 2 percent slopes ...... 97 123—Sluka silt loam, 1 to 4 percent 99—Rad silt loam, 2 to 4 percent slopes ...... 97 slopes ...... 114 100—Rad silt loam, 4 to 8 percent slopes ...... 98 124—Sluka silt loam, 4 to 8 percent 101—Rad silt loam, 8 to 12 percent slopes ...... 115 slopes ...... 99 125—Sluka silt loam, 8 to 12 percent 102—Rad silt loam, 12 to 20 percent slopes ...... 116 slopes ...... 99 126—Sluka-Purdam association, 15 103—Ragpie-Flatron complex, 2 to 20 to 50 percent slopes ...... 116 percent slopes ...... 100 127—Stricker-Nawt-Rock outcrop 104—Rakane-Blacknest complex, 1 to association, 15 to 30 percent 4 percent slopes ...... 101 slopes ...... 117 8

128—Stricker-Nawt-Rock outcrop Land Capability Classification ...... 137 association, 30 to 75 percent Rangeland ...... 138 slopes ...... 118 Windbreaks and Environmental Plantings ...... 139 129—Suepert-Taunton complex, 1 to Recreation ...... 140 15 percent slopes ...... 119 Wildlife ...... 140 130—Tanner silt loam, 1 to 10 percent Ungulates ...... 140 slopes ...... 120 Avians ...... 141 131—Tanner-Pigtail complex, 1 to 8 Waterfowl ...... 142 percent slopes ...... 121 Raptors ...... 142 132—Taunton sandy loam, 1 to 4 Furbearers ...... 142 percent slopes ...... 122 Fisheries ...... 142 133—Taunton sandy loam, 4 to 8 percent Threatened and Endangered Species ...... 142 slopes ...... 122 Engineering ...... 143 134—Taunton silt loam, 2 to 4 percent Building Site Development ...... 143 slopes ...... 123 Sanitary Facilities ...... 144 135—Tock loam, 1 to 6 percent slopes ...... 123 Construction Materials ...... 145 136—Trevino silt loam, 0 to 2 percent Water Management ...... 147 slopes ...... 124 Soil Properties ...... 149 137—Trevino silt loam, 2 to 8 percent Engineering Index Properties ...... 149 slopes ...... 124 Physical and Chemical Properties ...... 150 138—Trevino-Rock outcrop complex, 2 Soil and Water Features ...... 151 to 20 percent slopes ...... 125 Classification of the Soils ...... 155 139—Tucker silt loam, 0 to 2 percent Soil Series and Their Morphology...... 155 slopes ...... 126 Ackett Series ...... 156 140—Tulch silt loam, 0 to 2 percent Aeric Fluvaquents ...... 157 slopes ...... 126 Amboat Series ...... 157 141—Udaho very gravelly loam, 10 to Aninto Series ...... 158 30 percent slopes ...... 127 Antelope Springs Series ...... 159 142—Udaho very gravelly loam, 30 to Arbidge Series ...... 160 65 percent slopes ...... 128 Arness Series ...... 161 143—Wagonjacket silt loam, 0 to 1 Bahem Series ...... 162 percent slopes ...... 128 Banbury Series ...... 163 144—Weash gravelly sandy loam, 2 to Bancy Series ...... 163 12 percent slopes ...... 129 Barrymore Series ...... 164 145—Windypoint-Arbidge complex, 1 to Blacknest Series ...... 165 4 percent slopes ...... 129 Bluegulch Series ...... 166 146—Yahoo silt loam, 0 to 1 percent Brose Series ...... 166 slopes ...... 131 Budlewis Series ...... 168 147—Yahoo silt loam, 1 to 4 percent Chayson Series...... 169 slopes ...... 131 Chiara Series ...... 170 148—Zola loam, 0 to 2 percent slopes ...... 132 Chuska Series ...... 170 Prime Farmland ...... 133 Colthorp Series ...... 171 Use and Management of the Soils ...... 135 Congle Series ...... 172 Crops and Pasture ...... 135 Dehana Series ...... 173 Yields per Acre ...... 137 Dolman Series ...... 174 9

Doodlelink Series ...... 175 Rogerson Series ...... 212 Eep Series ...... 175 Roseworth Series ...... 213 Elhina Series ...... 176 Roza Series ...... 214 Elijah Series ...... 177 Ruclick Series ...... 215 Emberton Series ...... 178 Rutherford Series ...... 215 Fathom Series ...... 179 Schnipper Series...... 216 Flatron Series ...... 179 Scoon Series ...... 217 Forvic Series ...... 180 Shabliss Series ...... 218 Gosinta Series ...... 181 Shano Series ...... 219 Harsan Series ...... 182 Sidlake Series ...... 219 Hogmalat Series ...... 183 Sluka Series ...... 220 Hoosegow Series ...... 184 Starbuck Series...... 221 Howcree Series ...... 184 Stricker Series ...... 222 Hutton Series ...... 185 Suepert Series ...... 222 Ibola Series ...... 186 Tanner Series ...... 223 Idow Series ...... 187 Taunton Series ...... 224 Isknat Series ...... 188 Tock Series ...... 225 Iwica Series ...... 189 Trevino Series ...... 226 Jestrick Series ...... 190 Tucker Series ...... 226 Kavon Series ...... 190 Tulch Series ...... 227 Kecko Series ...... 191 Udaho Series ...... 228 Keman Series ...... 192 Wagonjacket Series ...... 229 Kudlac Series ...... 193 Weash Series...... 230 Lankbush Series ...... 194 Windypoint Series ...... 230 Lud Series ...... 195 Xerorthents ...... 231 Mackey Series ...... 196 Yahoo Series ...... 232 McCain Series ...... 197 Zola Series ...... 233 Minidoka Series ...... 197 Formation of the Soils ...... 235 Minveno Series ...... 198 Climate ...... 235 Mug Series ...... 199 Living Organisms ...... 236 Nawt Series ...... 199 Topography...... 236 Oshone Series ...... 200 Time ...... 237 Owinza Series ...... 202 Parent Material ...... 237 Owsel Series ...... 203 Recent and Pleistocene Deposits ...... 237 Paniogue Series ...... 203 Pliocene Deposits ...... 238 Paulville Series ...... 204 References ...... 241 Pigtail Series ...... 205 Glossary ...... 243 Player Series ...... 206 Tables ...... 255 Portneuf Series ...... 207 Table 1.--Temperature and Precipitation ...... 256 Power Series ...... 207 Table 2.--Freeze Dates in Spring and Fall ...... 259 Purdam Series ...... 208 Table 3.--Growing Season ...... 261 Quincy Series ...... 209 Table 4.--Acreage and Proportionate Extent Rad Series ...... 210 of the Soils ...... 262 Ragpie Series ...... 211 Table 5.--Yields Per Acre of Crops and Rakane Series ...... 211 Pasture ...... 265 10

Table 6.--Rangeland Productivity and Table 11.--Water Management ...... 330 Characteristic Plant Communities ...... 271 Table 12.--Engineering Index Properties ...... 342 Table 7.--Windbreaks and Environmental Table 13.--Physical and Chemical Plantings ...... 290 Properties of the Soils ...... 376 Table 8.--Building Site Development ...... 294 Table 14.--Water Features ...... 392 Table 9.--Sanitary Facilities...... 306 Table 15.--Soil Features ...... 399 Table 10.--Construction Materials ...... 318 Table 16.--Classification of the Soils ...... 406

Issued 1998 11

Foreword

This soil survey contains information that can be used in land-planning programs in Jerome County and part of Twin Falls County, Idaho. It contains predictions of soil behavior for selected land uses. The survey also highlights limitations and hazards inherent in the soil, improvements needed to overcome the limitations, and the impact of selected land uses on the environment. 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. 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. Broad areas of soils are shown on the general soil map. 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 the local office of the Natural Resources Conservation Service or the Cooperative Extension Service.

Luana E. Kiger State Conservationist Natural Resources Conservation Service

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Soil Survey of Jerome County and Part of Twin Falls County, Idaho

By Dal Ames, Natural Resources Conservation Service

Fieldwork by Dal Ames, Daryl Lund, Donnie Holbrook, and Kimberly Blake, Natural Resources Conservation Service

United States Department of Agriculture, Natural Resources Conservation Service in cooperation with United States Department of the Interior, Bureau of Land Management; University of Idaho, College of Agriculture; and Idaho Soil Conservation Commission

Older surveys of Jerome Area, Idaho, and Twin Falls Area, Idaho, were published in 1927 (13) and 1921 (12), respectively. These earlier surveys cover a part of the present survey. The present survey, however, updates the earlier surveys and provides additional information and larger maps that show the soils in greater detail. Descriptions, names, and delineations of soils in this soil survey do not fully agree with those on soil maps for adjacent surveys, including Minidoka Area, Idaho; Cassia County, Idaho, Western Part; Elko County, Northeast Part, Nevada; and Elmore County, Idaho. Jerome County and Part of Twin Falls County is in south-central Idaho (fig. 1). It includes private, State, and Federal land. The portion of the Sawtooth National Forest in Twin Falls County was excluded from the survey area. Figure 1.—Location of Jerome County and Part of Twin Federal land in the area is administrated by the Falls County in Idaho. Bureau of Land Management. The survey area comprises about 2,396 square miles, of which 387,300 acres is in Jerome County and deep and about 30 miles long. It was created 1,161,600 acres is in Twin Falls County. In 1991 partially by the Bonneville Flood. The overflow of the population of the county seats was about ancient Lake Bonneville also scoured an area 7,000 in Jerome and 27,000 in Twin Falls. about 6 miles wide and 30 miles long in Jerome The northern two-thirds of the survey area is County. The overflow emptied back into the generally flat, but it is marked by shield canyon at the Blue Lakes Alcove. Fifteen miles volcanoes and volcanic vents. It is drained by further downstream the flood created Mellon the Snake River, which flows from east to west Valley, which is north and west of Buhl, Idaho. through a canyon that is as much as 500 feet This is an area characterized by basaltic “melons” 14 Soil Survey

that are one foot to more than 20 feet in diameter establishment of Jerome and Twin Falls Counties. (8). The southern one-third of the survey area is The city of Twin Falls was platted in 1904, and an upland composed of terraces, basins, ridges, Twin Falls County was formed from the western and summits incised south to north by canyon part of Cassia County in 1907. In 1919 Jerome drainageways. Salmon Falls Creek drains this County was created from parts of Minidoka, area through a canyon as much as 400 feet deep. Lincoln, and Gooding Counties. The city of The creek empties into the Snake River in the Jerome was founded the same year. The towns of northwestern part of the survey area. Buhl, Jerome, and Twin Falls became the main The lowest point in the survey area, about shopping and industrial centers. Other smaller 2,700 feet in elevation, is along the Snake River, towns served as secondary shopping centers for in the northwestern corner of the area. The their immediate areas. towns of Jerome and Twin Falls, which are in the north-central part of the survey area, are about Water Supply 3,700 feet in elevation. Hollister, which is centrally located in the area, is about 4,500 feet Seasonal runoff and the Snake Plain aquifer in elevation. The highest point, about 7,700 feet supply the water used for irrigation in the area. in elevation, is in the extreme southwestern Irrigation water is available from reservoirs and corner of Twin Falls County. small stream storage areas and is pumped from creeks, rivers, and wells. Milner Dam on the General Nature of the Survey Snake River, Salmon Falls Dam on Salmon Falls Creek, and Cedar Creek Dam on Cedar Creek, Area which were constructed shortly after the turn of the century, are the main reservoirs. Stored This section gives general information water from these dams irrigates about 85 concerning Jerome County and part of Twin percent of the cropland in the survey area. The Falls County. It discusses history and remaining cropland is irrigated by water pumped development, water supply, agriculture, and from the Snake River, Salmon Falls Creek, and climate. the Snake River aquifer. Stockwater for the rangeland in the area is obtained from streams, History and Development springs, and wells. Wells, which are supplied by the Snake River The first known inhabitants in the survey area aquifer, provide the water for domestic, were Shoshone and Northern Paiute Indians, municipal, and industrial use. Average well depth who seasonally migrated between the Snake is about 200 to 320 feet, but depth ranges from River and the southern uplands. In 1811 the artesian to more than 600 feet (5). Wells north of Pacific Fur Company explored the area. Beaver the Snake River generally are deeper than those trappers frequented the local streams in the on the southern side of the survey area. Hot 1820's and 1830's. The Oregon Trail, which water wells are used for heat and recreation. generally followed the Snake River, was established in 1843. Emigrants passed through the area until 1863, when the Halliday Stage Agriculture Line built Home Station on Rock Creek. Two years later Rock Creek Station, the area's first Cattle ranches were the dominant agricultural store, was erected next to Home Station. About industry in the survey area before the 1865 gold was discovered along the Snake development of irrigated farmland. Livestock still River. The placer mining camps of Dry Town, provide almost one-half of the agricultural Mudbarville, Springtown, and Waterbug boomed, income, and about 65 percent of the land in the but they were busted by 1875. area is used for livestock. Irrigation projects Cattle ranching, an important industry in the reduced the acreage of rangeland by about 30 late 1870's, remained the main industry in the percent, but many farms still have small cow-calf survey area until the availability of irrigation or beef operations. Dairies, which furnish water for farming. In 1903 Milner Dam on the products statewide, and stock operations are Snake River was completed. Farmers then settled increasing. Sheep and hogs are raised on a few the central part of the area, which resulted in the farms (6). Jerome-Twin Falls, Idaho 15

Sparse rainfall makes irrigation essential for temperature on record at Hollister was -27 successful farming. The Reclamation Act of degrees recorded on December 22, 1990; at 1902 provided funds for construction of Jerome, -24 degrees recorded on December 22, reservoirs, canals, and irrigation control 1990; and at Twin Falls, -21 degrees recorded on structures that began operating in 1904. The December 23, 1990. In summer, the average main crops grown in the area are spring wheat, daily temperature is 67.2 degrees at Hollister, alfalfa hay, barley, winter wheat, dry beans, 69.9 degrees at Jerome, and 66.2 degrees at Twin potatoes, sugar beets, and corn silage. The total Falls and the average daily maximum acreage used for each crop varies as crop temperature is 82.9 degrees at Hollister, 87.1 prices fluctuate. Irrigation water is applied mainly degrees at Jerome, and 81.5 degrees at Twin by surface methods, but some sprinkler systems Falls. The highest temperature on record at are used. Use of commercial fertilizers and Hollister was 101 degrees on August 7, 1983; at improved varieties of crops has increased Jerome, 106 degrees on August 9, 1990; and at overall average yields. Twin Falls, 101 degrees on July 11, 1973. Three soil conservation districts and one soil Growing degree days, shown in table 1, are and water conservation district serve the area. equivalent to “heat units.” During the month, The North Side Soil Conservation District was growing degree days accumulate by the amount founded in 1946, the Twin Falls Soil that the average temperature each day exceeds Conservation District in 1951, the Balanced a base temperature (40 degrees). The normal Rock Soil Conservation District in 1961, and the monthly accumulation is used to schedule single Snake River Soil and Water Conservation or successive plantings of a crop between the District in 1966. These districts work to control last freeze in spring and the first freeze in fall. water and wind erosion by encouraging The total annual precipitation is about 10.14 minimum tillage and efficient use of irrigation inches at Hollister, 10.23 inches at Jerome, and water while promoting agricultural research to 10.60 inches at Twin Falls. Of this, about 3 improve crop yields and rangeland conditions. inches, or 30 percent, usually falls in June These districts have started numerous clean through September. The growing season for water projects that have reduced soil erosion on most crops falls within this period. The heaviest cropland and sedimentation of perennial 1-day rainfall recorded was 1.91 inches on May streams. 8, 1995, at Hollister; 1.63 inches on April 21, 1981, at Jerome; and 1.55 inches on May 8, Climate 1995, at Twin Falls. Thunderstorms occur on about 15 days each year, and most occur during Prepared by the Natural Resources Conservation Service, the period May through August. Water and Climate Center, Portland, Oregon. The average seasonal snowfall is 23 inches at Hollister, 19.1 inches at Jerome, and 28.7 inches The climate tables were created from data at Twin Falls. The greatest snow depth at any one recorded at Hollister, Jerome, and Twin Falls, time on record at Hollister was 12 inches on Idaho, during the period 1961 to 1990. December 29, 1992; at Jerome, 13.7 inches on Thunderstorm days, relative humidity, percent January 19, 1964; and at Twin Falls, 14 inches on sunshine, and wind information were estimated November 30, 1985. from data recorded at the first order station at The average relative humidity in midafternoon Boise, Idaho. is about 40 percent. Humidity is higher at night, Table 1 gives data on temperature and and the average at dawn is about 65 percent. precipitation for the survey area as recorded at The sun shines 83 percent of the time in Hollister, Jerome, and Twin Falls. Table 2 shows summer and 45 percent of the time in winter. probable dates of the first freeze in fall and the The prevailing wind is from the west. Average last freeze in spring. Table 3 provides data on the windspeed is highest, 10 miles per hour, in length of the growing season. March. In winter, the average daily temperature is 29.9 degrees F at Hollister, 29.3 degrees at Jerome, How This Survey Was Made and 29.1 degrees at Twin Falls and the average daily minimum temperature is 20.5, 20.1, and This survey was made to provide information 20.5 degrees, respectively. The lowest about the soils and miscellaneous areas in the 16 Soil Survey

survey area. The information includes a soil characteristics with precisely defined limits. description of the soils and miscellaneous areas The classes are used as a basis for comparison and their location and a discussion of their to classify soils systematically. Soil taxonomy, suitability, limitations, and management for the system of taxonomic classification used in specified uses. Soil scientists observed the the United States, is based mainly on the kind steepness, length, and shape of the slopes; the and character of soil properties and the general pattern of drainage; the kinds of crops arrangement of horizons within the profile. After and native plants; and the kinds of bedrock. the soil scientists classified and named the They dug many holes to study the soil profile, soils in the survey area, they compared the which is the sequence of natural layers, or individual soils with similar soils in the same horizons, in a soil. The profile extends from the taxonomic class in other areas so that they surface down into the unconsolidated material in could confirm data and assemble additional data which the soil formed. The unconsolidated based on experience and research. material is devoid of roots and other living While a soil survey is in progress, samples of organisms and has not been changed by other some of the soils in the area generally are biological activity. collected for laboratory analyses and for The soils and miscellaneous areas in the engineering tests. Soil scientists interpret the survey area are in an orderly pattern that is data from these analyses and tests as well as related to the geology, landforms, relief, climate, the field-observed characteristics and the soil and natural vegetation of the area. Each kind properties to determine the expected behavior of soil and miscellaneous area is associated of the soils under different uses. Interpretations with a particular kind of landform or with a for all of the soils are field tested through segment of the landform. By observing the observation of the soils in different uses and soils and miscellaneous areas in the survey under different levels of management. Some area and relating their position to specific interpretations are modified to fit local segments of the landform, a soil scientist conditions, and some new interpretations are develops a concept or model of how they were developed to meet local needs. Data are formed. Thus, during mapping, this model assembled from other sources, such as enables the soil scientist to predict with a research information, production records, and considerable degree of accuracy the kind of soil field experience of specialists. For example, or miscellaneous area at a specific location on data on crop yields under defined levels of the landscape. management are assembled from farm records Commonly, individual soils on the landscape and from field or plot experiments on the same merge into one another as their characteristics kinds of soil. gradually change. To construct an accurate soil Predictions about soil behavior are based map, however, soil scientists must determine the not only on soil properties but also on such boundaries between the soils. They can observe variables as climate and biological activity. Soil only a limited number of soil profiles. conditions are predictable over long periods of Nevertheless, these observations, supplemented time, but they are not predictable from year to by an understanding of the soil-vegetation- year. For example, soil scientists can predict landscape relationship, are sufficient to verify with a fairly high degree of accuracy that a predictions of the kinds of soil in an area and to given soil will have a high water table within determine the boundaries. certain depths in most years, but they cannot Soil scientists recorded the characteristics of predict that a high water table will always be at a the soil profiles that they studied. They noted specific level in the soil on a specific date. color, texture, size and shape of soil aggregates, After soil scientists located and identified kind and amount of rock fragments, distribution of the significant natural bodies of soil in the plant roots, reaction, and other features that survey area, they drew the boundaries of these enable them to identify soils. After describing the bodies on aerial photographs and identified soils in the survey area and determining their each as a specific map unit. Aerial photographs properties, the soil scientists assigned the soils show trees, buildings, fields, roads, and rivers, to taxonomic classes (units). Taxonomic classes all of which help in locating boundaries are concepts. Each taxonomic class has a set of accurately. Jerome-Twin Falls, Idaho 17

This survey area was mapped at two levels units were designed to meet the needs for that of detail. At the more detailed level, map units use. are narrowly defined. Map unit boundaries were The descriptions, names, and delineations plotted and verified at closely spaced intervals. of the soils in this survey area do not fully agree At the less detailed level, map units are with those of the soils in adjacent survey areas. broadly defined. Boundaries were plotted and Differences are the result of a better knowledge verified at wider intervals. The detail of of soils, modifications in series concepts, or mapping was selected to meet the anticipated variations in the intensity of mapping or in the long-term use of the survey, and the map extent of the soils in the survey areas.

19

General Soil Map Units

The general soil map at the back of this Soil Descriptions publication shows broad areas that have a distinctive pattern of soils, relief, and drainage. Dominantly nearly level to moderately Each map unit on the general soil map is a sloping, mesic soils that are shallow to unique natural landscape. Typically, it consists very deep over a duripan, moderately of one or more major soils or miscellaneous deep over bedrock, and very deep and areas and some minor soils or miscellaneous formed in alluvium; on terraces areas. It is named for the major soils or miscellaneous areas. The components of one Number of map units: 5 map unit can occur in another but in a different Percentage of survey area: 44 percent pattern. The general soil map can be used to compare 1. Purdam-Rakane-Blacknest the suitability of large areas for general land uses. Areas of suitable soils can be identified on Well drained soils that are moderately deep the map. Likewise, areas where the soils are not over a duripan and very deep and have slopes suitable can be identified. of dominantly 1 to 15 percent Because of its small scale, the map is not suitable for planning the management of a farm Percentage of survey area: 6 percent or field or for selecting a site for a road or Elevation: 3,000 to 4,000 feet building or other structure. The soils in any one Frost-free period: 120 to 140 days map unit differ from place to place in slope, Average annual precipitation: 8 to 10 inches depth, drainage, and other characteristics that Position on landscape: Terraces affect management. Minor components: Bahem, Chuska, Dolman, Some soil boundaries and soil names on the Kudlac, Owsel, Roseworth, Scoon, Sluka, general soil map for this survey area do not Tulch, and Yahoo soils match those on the general soil maps for the Percentage of unit: Minor components—25 adjacent survey areas, including Minidoka Area, percent Idaho; Cassia County, Idaho, Western Part; Elko Present uses: Irrigated cropland and County, Northeast Part, Nevada; and Elmore rangeland County Area, Idaho. Differences are the result of changes in series concepts, variations in slope 2. Portneuf groupings, and the application of the latest soil classification system. The differences are Well drained soils that are very deep and have explained in detail in the final field review report slopes of dominantly 0 to 8 percent (available in the State office of the Natural Resources Conservation Service in Boise, Percentage of survey area: 15 percent Idaho). Elevation: 3,000 to 4,000 feet 20 Soil Survey

Frost-free period: 120 to 140 days 4. Power-McCain-Paulville Average annual precipitation: 8 to 10 inches Position on landscape: Terraces Well drained soils that are very deep and Minor components: Bahem, Dolman, Minidoka, moderately deep over basalt and have slopes of Minveno, Rad, Shano, Sluka, Trevino, and dominantly 1 to 8 percent Tulch soils Percentage of unit: Minor components—30 Percentage of survey area: 10 percent percent Elevation: 3,500 to 4,500 feet Present use: Irrigated cropland (fig. 2) Frost-free period: 120 to 140 days Average annual precipitation: 9 to 11 inches Position on landscape: Terraces Minor components: Barrymore, Hoosegow, Idow, and Owinza soils, Rock outcrop, Sidlake and Starbuck soils Percentage of unit: Minor components—30 percent Present uses: Rangeland and irrigated cropland

5. Kecko-Taunton-Harsan

Well drained soils that are very deep to moderately deep over a duripan and have slopes of dominantly 1 to 8 percent

Percentage of survey area: 3 percent Elevation: 2,900 to 4,400 feet Frost-free period: 120 to 140 days Figure 2.—Sugar beets in an area of general soil map Average annual precipitation: 8 to 10 unit 2 in foreground. inches Position on landscape: Terraces Minor components: Emberton, Jestrick, Quincy, 3. Sluka-Minveno and Sidlake soils Percentage of unit: Minor components—30 Well drained soils that are moderately deep and percent shallow over a duripan and have slopes of Present uses: Irrigated cropland and dominantly 0 to 8 percent rangeland

Percentage of survey area: 10 percent Rock outcrop, and dominantly nearly Elevation: 3,000 to 4,500 feet level to moderately sloping, mesic soils Frost-free period: 120 to 140 days that are shallow, moderately deep, and Average annual precipitation: 8 to 10 inches very deep over a duripan and shallow to Position on landscape: Terraces very deep over bedrock and formed in Minor components: Chiara, Minidoka, Portneuf, alluvium; on terraces, dip slopes, and Rad, and Trevino soils ridges Percentage of unit: Minor components—30 percent Number of map units: 7 Present use: Irrigated cropland Percentage of survey area: 34 percent Jerome-Twin Falls, Idaho 21

6. Rock outcrop-Banbury-Paulville Percentage of unit: Minor components—30 percent Rock outcrop, and well drained soils that are Present uses: Rangeland and irrigated cropland shallow and very deep over bedrock and have slopes of dominantly 2 to 6 percent 9. Lud-Elijah-Pigtail Percentage of survey area: 5 percent Well drained soils that are shallow and Elevation: 3,500 to 4,500 feet moderately deep over a duripan and have slopes Frost-free period: 120 to 140 days of dominantly 2 to 10 percent Average annual precipitation: 9 to 10 inches Position on landscape: Banbury and Paulville Percentage of survey area: 3 percent soils—terraces Elevation: 4,500 to 5,300 feet Minor components: Emberton, Kecko, Shano, Frost-free period: 100 to 120 days Suepert, and Taunton soils Average annual precipitation: 9 to 11 inches Percentage of unit: Minor components—15 Position on landscape: Terraces percent Minor components: Ackett, Owsel, and Tanner Present use: Rangeland soils Percentage of unit: Minor components-—10 7. Chuska-Colthorp percent Present use: Rangeland Well drained soils that are shallow over a duripan and have slopes of dominantly 2 to 12 percent 10. Chiara Well drained soils that are shallow over a duripan Percentage of survey area: 11 percent and have slopes of dominantly 1 to 8 percent Elevation: 4,200 to 5,500 feet Frost-free period: 100 to 120 days Percentage of survey area: 4 percent Average annual precipitation: 9 to 12 inches Elevation: 4,000 to 4,500 feet Position on landscape: Chuska soil—dip Frost-free period: 120 to 140 days slopes, ridges, and terraces; Colthorp Average annual precipitation: 8 to 10 inches soil—terraces Position on landscape: Terraces Minor components: Ackett, Lankbush, Owsel, Minor components: Bahem, Colthorp, Owsel, Purdam, Roseworth, Rogerson, Purdam, Shabliss, and Sluka soils Schnipper, Shabliss, Sluka, Udaho, and Percentage of unit: Minor components—20 Weash soils percent Percentage of unit: Minor components—30 Present uses: Rangeland and irrigated cropland percent Present uses: Rangeland and irrigated cropland 11. Windypoint-Arbidge

8. Roseworth Well drained soils that are moderately deep over a duripan or very deep over bedrock and have Well drained soils that are shallow over a slopes of dominantly 1 to 4 percent duripan and have slopes of dominantly 1 to 8 Percentage of survey area: 3 percent percent Elevation: 4,000 to 5,500 feet Percentage of survey area: 6 percent Frost-free period: 100 to 130 days Elevation: 4,000 to 4,600 feet Average annual precipitation: 8 to 12 inches Frost-free period: 100 to 120 days Position on landscape: Terraces Average annual precipitation: 8 to 10 inches Minor components: Antelope Springs, Blacknest, Position on landscape: Terraces Chuska, Owsel, Paulville, Purdam, Roza, Minor components: Blacknest, Bluegulch, and Scoon soils Chuska, Elijah, Lud, Owsel, Purdam, Percentage of unit: Minor components—20 Rakane, and Yahoo soils percent 22 Soil Survey

Present uses: Irrigated cropland and rangeland Number of map units: 6 Percentage of survey area: 18 percent

12. Ackett

Well drained soils that are shallow over a duripan 14. Tanner-Budlewis-Arness and have slopes of dominantly 2 to 10 percent Well drained soils that are shallow and moderately deep over a duripan and have slopes Percentage of survey area: 2 percent of dominantly 2 to 6 percent Elevation: 4,900 to 5,600 feet Frost-free period: 90 to 120 days Percentage of survey area: 2 percent Average annual precipitation: 10 to 12 inches Elevation: 5,100 to 6,000 feet Position on landscape: Stream terraces Frost-free period: 90 to 100 days Minor components: Aeric Fluvaquents; Chuska, Average annual precipitation: 11 to 15 Gosinta, Lankbush, Nawt, and Oshone soils; inches Rock outcrop; Stricker and Udaho soils; Position on landscape: Terraces Xerorthents Minor components: Aninto, Chayson, Chuska, Percentage of unit: Minor components—25 Eep, Howcree, Hutton, Iwica, and Pigtail percent soils; Rock outcrop; Xerorthents; and Udaho Present use: Rangeland soils Percentage of unit: Minor components—30 Rock outcrop, and dominantly steep to percent very steep, mesic soils that are shallow Present use: Rangeland to very deep over bedrock and formed in colluvium; on breaks Number of map units: 1 Percentage of survey area: 4 percent

13. Rock outcrop-Xerorthents

Rock outcrop, and well drained soils that are shallow to very deep over bedrock and have slopes of dominantly 40 to 75 percent

Percentage of survey area: 4 percent (fig. 3) Elevation: 2,800 to 5,500 feet Frost-free period: 100 to 140 days Average annual precipitation: 8 to 12 inches Position on landscape: Breaks Minor components: Ackett and Antelope Springs soils; areas of Badlands; Banbury, Chuska, Fathom, Kudlac, Roseworth, Trevino, and Figure 3.—Rock outcrop on upper slopes and Udaho soils Xerorthents on lower slopes in an area of general Percentage of unit: Minor components—35 soil map unit 13. Salmon Falls Creek flows through percent the area. Present use: Rangeland 15. Oshone-Aninto-Tock Dominantly gently sloping to steep, frigid and cryic soils that are shallow to Well drained soils that are moderately deep over very deep over bedrock and shallow and a duripan and very deep over bedrock and have moderately deep over a duripan and slopes of dominantly 1 to 12 percent formed in alluvium, colluvium, and residuum; on breaks, dip slopes, hill Percentage of survey area: 5 percent slopes, ridges, summits, and terraces Elevation: 5,200 to 6,100 feet Jerome-Twin Falls, Idaho 23

Frost-free period: 90 to 100 days deep over bedrock and have slopes of Average annual precipitation: 12 to 16 inches dominantly 15 to 60 percent Position on landscape: Terraces Percentage of survey area: 3 percent Minor components: Bancy, Doodlelink, Eep, Elevation: 4,300 to 6,400 feet Elhina, Forvic, Isknat, Nawt, Ruclick, Frost-free period: 80 to 110 days Stricker, Tanner, Tucker, Wagonjacket, and Average annual precipitation: 12 to 18 inches Zola soils Position on landscape: Breaks Percentage of unit: Minor components—40 Minor components: Congle, Gosinta, Mackey, percent Ruclick, and Udaho soils Present use: Rangeland Percentage of unit: Minor components—40 percent 16. Brose-Amboat-Ragpie Present use: Rangeland

Well drained soils that are shallow and very deep 19. Eep-Mug-Player over bedrock and have slopes of dominantly 2 to 20 percent Well drained soils that are very deep and moderately deep over bedrock and have slopes Percentage of survey area: 3 percent of dominantly 2 to 65 percent Elevation: 5,000 to 6,600 feet Percentage of survey area: 2 percent Frost-free period: 70 to 110 days Elevation: 5,400 to 6,500 feet Average annual precipitation: 12 to 16 inches Frost-free period: 60 to 100 days Position on landscape: Brose and Amboat Average annual precipitation: 12 to 20 inches soils—summits; Ragpie soils—ridges and Position on landscape: dip slopes Eep soils—hill slopes and breaks; Minor components: Congle, Doodlelink, Flatron, Mug soils—terraces; Player soils— and Ruclick soils breaks Percentage of unit: Minor components—25 Minor components: Dehana, Keman, Hogmalat, percent and Rutherford soils Present use: Rangeland Percentage of unit: Minor components—15 percent Present use: Rangeland 17. Keman-Dehana-Rutherford

Well drained soils that are very deep and moderately deep over bedrock and have slopes of dominantly 2 to 25 percent Percentage of survey area: 3 percent (fig. 4) Elevation: 5,800 to 7,700 feet Frost-free period: 20 to 60 days Average annual precipitation: 15 to 25 inches Position on landscape: Keman soils—summits; Dehana soils—hill slopes and breaks; Rutherford soils—ridges and dip slopes Minor components: Eep, Hogmalat, and Kavon soils Percentage of unit: Minor components—25 percent Present use: Rangeland

18. Doodlelink-Stricker-Nawt Figure 4.—Area of general soil map unit 17. Keman soils in foreground, Dehana soils on wooded hillsides, Well drained soils that are very deep and and Rutherford soils on ridgetops.

25

Detailed Soil Map Units

The map units delineated on the detailed mapped separately because of the scale used. maps at the back of this survey represent the Some small areas of strongly contrasting soils or soils or miscellaneous areas in the survey area. miscellaneous areas are identified by a special The map unit descriptions in this section, along symbol on the maps. The included areas of with the maps, can be used to determine the contrasting soils or miscellaneous areas are suitability and potential of a unit for specific uses. mentioned in the map unit descriptions. A few They also can be used to plan the management included areas may not have been observed, needed for those uses. More information about and consequently they are not mentioned in the each map unit is given under the heading “Use descriptions, especially where the pattern was so and Management of the Soils.” complex that it was impractical to make enough A map unit delineation on a map represents observations to identify all the soils and an area dominated by one or more major kinds miscellaneous areas on the landscape. of soil or miscellaneous areas. A map unit is The presence of included areas in a map unit identified and named according to the taxonomic in no way diminishes the usefulness or accuracy classification of the dominant soils or of the data. The objective of mapping is not to miscellaneous areas. Within a taxonomic class delineate pure taxonomic classes but rather to there are precisely defined limits for the separate the landscape into landforms or properties of the soils. On the landscape, landform segments that have similar use and however, the soils and miscellaneous areas are management requirements. The delineation of natural phenomena, and they have the such segments on the map provides sufficient characteristic variability of all natural information for the development of resource phenomena. Thus, the range of some observed plans, but if intensive use of small areas is properties may extend beyond the limits defined planned, onsite investigation is needed to define for a taxonomic class. Areas of soils of a single and locate the soils and miscellaneous areas. taxonomic class rarely, if ever, can be mapped An identifying symbol precedes the map unit without including areas of other taxonomic name in the map unit descriptions. Each classes. Consequently, every map unit is made description includes general facts about the unit up of the soils or miscellaneous areas for which it and gives the principal hazards and limitations to is named and some “included” areas that belong be considered in planning for specific uses. to other taxonomic classes. Soils that have profiles that are almost alike Most included soils have properties similar to make up a soil series. Except for differences in those of the dominant soil or soils in the map texture of the surface layer, all the soils of a unit, and thus they do not affect use and series have major horizons that are similar in management. These are called noncontrasting, composition, thickness, and arrangement. or similar, inclusions. They may or may not be Soils of one series can differ in texture of the mentioned in the map unit description. Other surface layer, slope, stoniness, salinity, degree of included soils and miscellaneous areas, erosion, and other characteristics that affect their however, have properties and behavioral use. On the basis of such differences, a soil characteristics divergent enough to affect use or series is divided into soil phases. Most of the to require different management. These are areas shown on the detailed soil maps are called contrasting, or dissimilar, inclusions. They phases of soil series. The name of a soil phase generally are in small areas and could not be commonly indicates a feature that affects use or 26 Soil Survey

management. For example, Taunton sandy loam, In the map unit descriptions that follow, a 1 to 4 percent slopes, is a phase of the Taunton semitabular format is used. In this format a series. boldface heading (for example, Composition) is Some map units are made up of two or more used to identify the kind of information grouped major soils or miscellaneous areas. These map directly below it. Introducing each item of units are complexes, associations, or information under the heading is an italicized undifferentiated groups. term or phrase (for example, Position on A complex consists of two or more soils or landscape:) that identifies or describes the miscellaneous areas in such an intricate pattern information. Many of the boldface headings and or in such small areas that they cannot be introductory terms or phrases are self- shown separately on the maps. The pattern explanatory; however, some of them need further and proportion of the soils or miscellaneous explanation. These explanations are provided in areas are somewhat similar in all areas. Brose- the following paragraphs, generally in the order in Amboat complex, 2 to 20 percent slopes, is an which they are used in the map unit descriptions. example. Composition is given for the components An association is made up of two or more identified in the name of the map unit as well as geographically associated soils or miscellaneous for the contrasting inclusions. areas that are shown as one unit on the maps. Inclusions are areas of components (soils or Because of present or anticipated uses of the miscellaneous areas) that differ from the map units in the survey area, it was not components for which the unit is named. considered practical or necessary to map the Inclusions can be either similar or contrasting. soils or miscellaneous areas separately. The Similar inclusions are components that differ pattern and relative proportion of the soils or from the components for which the unit is named miscellaneous areas are somewhat similar. but that for purposes of use and management Stricker-Nawt-Rock outcrop association, 15 to 30 can be considered to be the same as the named percent slopes, is an example. components. Note that in the “Composition” This survey includes miscellaneous areas. paragraph a single percentage is provided for a Such areas have little or no soil material and named soil and the similar inclusions because support little or no vegetation. Rock outcrop- their use and management are similar. Xerorthents complex, very steep, is an example. Contrasting inclusions are components that Some of the boundaries on the detailed soil differ sufficiently from the components for which maps of the Jerome County and Part of Twin the unit is named that they would have different Falls County, Idaho, soil survey do not match use and management if they were extensive those on the soil maps of adjacent soil surveys enough to be managed separately. For most of Minidoka Area, Idaho; Cassia County, Idaho, uses, contrasting inclusions have limited effect Western Part; Elko County, Northeast Part, on use and management. Inclusions generally Nevada; and Elmore County Area, Idaho. Some are in small areas, and they could not be of the soil names and descriptions do not fully mapped separately because of the scale used. agree. Differences are the result of modifications Some small areas of strongly contrasting or refinements in soil series concepts, variations inclusions are identified by a special symbol on in the intensity of mapping, or the extent of the the detailed soil maps. A few inclusions may not soils in the survey area. The differences are have been observed, and consequently they explained in detail in the final field review report are not mentioned in the descriptions, especially (on file in the Natural Resources Conservation where the pattern was so complex that it was Service State office in Boise, Idaho). impractical to make enough observations to Table 4 gives the acreage and proportionate identify all the inclusions on the landscape. extent of each map unit. Other tables (see “Table Position on landscape refers to the dominant of Contents”) give properties of the soils and the position or positions on which the component limitations, capabilities, and potentials for many is located. In naming landscape positions, an uses. The Glossary defines many of the terms effort has been made to give the specific position used in describing the soils or miscellaneous of the component rather than a general position areas. that could encompass other components. In Jerome-Twin Falls, Idaho 27

some instances, however, the component is distributed over a larger landscape to such a degree that it is more nearly accurate to name the larger landscape positions rather than the local ones. Typical profile is a vertical, two-dimensional section of the soil extending from the surface to a restrictive layer or to a depth of 60 inches or more. Depth class is an adjective term (for example, moderately deep) for the depth of the soil. Permeability is the quality of the soil that enables water to move downward through the profile. Permeability is measured as the number of inches per hour that water moves downward through the saturated soil. Available water capacity is the capacity of the soil to hold water available for use by most plants. It commonly is expressed as inches of water per inch of soil (see “Glossary”). Hazard of water erosion refers to the hazard if protective plant cover is removed. The hazard of erosion is constant and cannot be increased or Figure 5.—Area of Ackett extremely gravelly clay loam, 2 reduced. to 10 percent slopes, in foreground. Major uses are the dominant uses at the time the major part of the fieldwork for this survey was Setting completed. Position on landscape: Stream terraces (fig. 5) Major management factors are those factors Elevation: 4,900 to 5,600 feet that affect the use of the soils for the major uses. Average annual precipitation: 10 to 12 inches The soil-related factors are limiting, whereas the Average annual air temperature: 46 to 49 climatic factors can be either limiting or degrees F nonlimiting. The major management factors may Frost-free season: 90 to 120 days apply to the entire unit or to a given component of the unit. Characteristics of the Ackett Soil General management considerations provide additional perspective on the suitability and Typical profile: limitations of the unit for the major uses. They 0 to 1 inch—pale brown extremely gravelly may apply to the entire unit or to a given clay loam component of the unit. 1 inch to 6 inches—light brownish gray and pale brown clay 6 to 8 inches—light gray extremely cobbly clay Soil Descriptions 8 to 14 inches—very pale brown very gravelly clay loam 14 to 28 inches—white lime- and silica- 1—Ackett extremely gravelly clay cemented hardpan loam, 2 to 10 percent slopes 28 to 50 inches—multicolored extremely gravelly sand 50 inches—bedrock Composition Depth class: Shallow to a hardpan Ackett soil and similar inclusions—85 percent Drainage class: Well drained Contrasting inclusions—15 percent Permeability: Very slow 28 Soil Survey

Available water capacity: 1.5 to 3.0 inches Average annual air temperature: 46 to 49 Potential rooting depth: 10 to 20 inches degrees F Runoff: Slow Frost-free season: 90 to 120 days Hazard of water erosion: Slight Shrink-swell potential: High Characteristics of the Ackett Soil Salinity throughout profile: Low or moderate Typical profile: 0 to 4 inches—light brownish gray extremely Contrasting Inclusions gravelly clay loam 4 to 6 inches—pale brown clay Arbidge soils on lower lying terraces; Chuska 6 to 11 inches—light brownish gray and Roseworth soils on higher lying terraces; extremely cobbly clay Lankbush soils on foot slopes; soils that are 11 to 22 inches—white lime- and silica- deep to a hardpan, are loam over clay loam, cemented hardpan and are on mounds; barren areas that are 10 22 to 42 inches—multicolored extremely to 20 feet in diameter and are saline, are gravelly sand shallow and clayey, or are subject to ant 42 inches—bedrock activity Depth class: Shallow to a hardpan Use and Management Drainage class: Well drained Permeability: Very slow Major use: Rangeland Available water capacity: 1 inch to 2 inches Major management factors: Precipitation, Potential rooting depth: 10 to 20 inches available water capacity, depth to the Runoff: Medium hardpan, rock fragments in the surface l Hazard of water erosion: Moderate ayer Shrink-swell potential: High Dominant vegetation in natural potential plant Salinity throughout profile: Low or moderate community: Thurber needlegrass, black sagebrush Contrasting Inclusions General management considerations: Soils that are deep to a hardpan, are loam over • Forage production is limited by low clay loam, and are on mounds; Udaho soils precipitation, low available water capacity, and in lower lying areas of hillsides shallow rooting depth. • Seeding is limited by low precipitation and rock Use and Management fragments in the surface layer. Major use: Rangeland Interpretive Groups Major management factors: Precipitation, available water capacity, depth to the Land capability classification: VIIs, nonirrigated hardpan, rock fragments in the surface layer, Range site: Shallow stony, 8 to 12 inch hazard of water erosion precipitation zone Dominant vegetation in natural potential plant community: Thurber needlegrass, black 2—Ackett extremely gravelly clay sagebrush loam, 10 to 25 percent slopes General management considerations: • Forage production is limited by low precipitation, low available water capacity, and Composition the shallow rooting depth. • Seeding is limited by low precipitation, rock Ackett soil and similar inclusions—85 percent fragments in the surface layer, and the moderate Contrasting inclusions—15 percent hazard of water erosion. Setting Interpretive Groups Position on landscape: Stream terraces Elevation: 4,900 to 5,600 feet Land capability classification: VIIe, nonirrigated Average annual precipitation: 10 to 12 Range site: Shallow stony, 8 to 12 inch inches precipitation zone Jerome-Twin Falls, Idaho 29

3—Aeric Fluvaquents • Forage production and seeding are limited by wetness. • Grazing should be delayed until the soil is Composition adequately drained and is firm enough to Aeric Fluvaquents and similar inclusions—70 withstand trampling by livestock. percent Interpretive Groups Contrasting inclusions—30 percent Land capability classification: IVw, nonirrigated Setting Range site: Because of the variability of these Position on landscape: Flood plains soils, onsite evaluation is necessary to Elevation: 5,000 to 5,500 feet determine the range site in specific areas. Average annual precipitation: 8 to 12 inches Average annual air temperature: 47 to 49 degrees F 4—Aninto gravelly loam, 1 to 6 Frost-free season: 100 to 110 days percent slopes Slope range: 0 to 2 percent Composition Characteristics of the Aeric Aninto soil and similar inclusions—80 percent Fluvaquents Contrasting inclusions—20 percent Example profile: Setting 0 to 13 inches—light brownish gray silty clay loam Position on landscape: Terraces 13 to 18 inches—dark gray silty clay Elevation: 5,700 to 5,850 feet 18 to 60 inches—pale brown loamy sand Average annual precipitation: 12 to 16 inches Depth class: Very deep Average annual air temperature: 42 to 44 Drainage class: Somewhat poorly drained to very degrees F poorly drained Frost-free season: 90 to 100 days Permeability: Slow or moderate Characteristics of the Aninto Soil Available water capacity: 2 to 10 inches Potential rooting depth: 18 to 36 inches Typical profile: Runoff: Slow 0 to 12 inches—grayish brown gravelly loam Hazard of water erosion: Slight 12 to 20 inches—pale brown very gravelly Depth to water table: 6 to 36 inches clay Frequency of flooding: Frequent 20 to 40 inches—light yellowish brown Shrink-swell potential: High extremely gravelly silty clay 40 to 53 inches—light yellowish brown very Contrasting Inclusions gravelly clay Lankbush soils on foot slopes; soils that are 53 to 69 inches—light yellowish brown moderately deep to sand and gravel, are silty extremely gravelly silty clay clay loam, and are on flood plains; soils that Depth class: Very deep are moderately well drained and very deep, Drainage class: Well drained are silty clay loam over silty clay, and are on Permeability: Very slow flood plains Available water capacity: 4 to 6 inches Potential rooting depth: 60 inches or more Use and Management Runoff: Slow Hazard of water erosion: Slight Major use: Rangeland Shrink-swell potential: Moderate Major management factor: Wetness Contrasting Inclusions Dominant vegetation in natural potential plant community: Slender wheatgrass, foxtail Brose soils on summits; Howcree and Oshone barley, basin wildrye, sedge, willow soils on higher lying terraces; Tucker soils on General management considerations: flood plains; soils that are very deep, are 30 Soil Survey

gravelly loam over gravelly clay, and are on Permeability: Very slow fans and mounds; soils that are poorly Available water capacity: 6 to 8 inches drained and very deep, are silt loam over Potential rooting depth: 60 inches or more silty clay, and are in depressions of flood Runoff: Rapid plains Hazard of water erosion: Severe Shrink-swell potential: High Use and Management Characteristics of the Aninto Soil, Thick Major use: Rangeland Surface Major management factors: None Dominant vegetation in natural potential plant Slope range: 10 to 20 percent community: Idaho fescue, mountain big Typical profile: sagebrush 0 to 12 inches—grayish brown very gravelly silty clay loam Interpretive Groups 12 to 33 inches—yellowish brown very Land capability classification: IVe, nonirrigated gravelly clay Range site: Loamy, 13 to 16 inch precipitation 33 to 57 inches—brown extremely gravelly zone silty clay 57 to 65 inches—brown clay loam Depth class: Very deep 5—Aninto complex, 10 to 30 percent Drainage class: Well drained slope Permeability: Very slow Available water capacity: 5 to 7 inches Composition Potential rooting depth: 60 inches or more Runoff: Medium Aninto soil and similar inclusions—45 percent Hazard of water erosion: Moderate Aninto soil, thick surface, and similar Shrink-swell potential: Moderate inclusions—40 percent Contrasting inclusions—15 percent Contrasting Inclusions Setting Bancy, Chayson, Forvic, and Oshone soils on terraces Position on landscape: Aninto soil—convex areas of terraces; Aninto soil, thick surface— Use and Management concave areas and foot slopes of terraces Major use: Rangeland Elevation: 5,500 to 6,000 feet Major management factors: Depth to the clayey Average annual precipitation: 12 to 16 inches subsoil, hazard of water erosion Average annual air temperature: 42 to 44 Dominant vegetation in natural potential plant degrees F community: Aninto soil—Idaho fescue, low Frost-free season: 90 to 100 days sagebrush; Aninto soil, thick surface—Idaho Characteristics of the Aninto Soil fescue, mountain big sagebrush General management considerations: Slope range: 10 to 30 percent • Forage production and rooting depth are Typical profile: limited by the shallow depth to the clayey subsoil 0 to 6 inches—brown very gravelly silty clay in the Aninto soil. loam • Seeding is limited by the hazard of water 6 to 13 inches—brown very gravelly clay erosion. 13 to 26 inches—brown very gravelly silty clay Interpretive Groups 26 to 41 inches—yellowish brown extremely gravelly silty clay Land capability classification: IVe, nonirrigated 41 to 56 inches—dark yellowish brown clay Range site: Aninto soil—Shallow claypan, 12 to 56 to 70 inches—brown clay loam 16 inch precipitation zone; Aninto soil, thick Depth class: Very deep surface—Loamy, 13 to 16 inch precipitation Drainage class: Well drained zone Jerome-Twin Falls, Idaho 31

6—Antelope Springs loam, 0 to 4 • Forage production is limited by low percent slopes precipitation and soil salinity. • Seeding is limited by low precipitation, soil salinity, and the moderate hazard of wind Composition erosion. Antelope Springs soil and similar inclusions—85 • Plants that can tolerate the soil salinity should percent be seeded. Contrasting inclusions—15 percent • Seeding generally is most successful late in fall; however, it may not be successful in years Setting when precipitation is below average during the Position on landscape: Alluvial fans and terraces growing season. Elevation: 3,000 to 4,500 feet Interpretive Groups Average annual precipitation: 8 to 10 inches Average annual air temperature: 49 to 51 Land capability classification: VIs, nonirrigated degrees F Range site: Saline upland, 7 to 12 inch Frost-free season: 110 to 140 days precipitation zone Characteristics of the Antelope Springs Soil 7—Arbidge sandy loam, 1 to 4 Typical profile: percent slopes 0 to 4 inches—pale brown loam 4 to 13 inches—brown clay loam Composition 13 to 60 inches—pale brown loam Arbidge soil and similar inclusions—90 percent Depth class: Very deep Contrasting inclusions—10 percent Drainage class: Well drained Permeability: Slow Setting Available water capacity: 7 to 8 inches Position on landscape: Terraces Potential rooting depth: 60 inches or more Elevation: 4,500 to 5,500 feet Runoff: Slow Average annual precipitation: 10 to 12 inches Hazard of water erosion: Slight Average annual air temperature: 45 to 48 Hazard of wind erosion: Moderate degrees F Shrink-swell potential: Moderate Frost-free season: 100 to 120 days Salinity throughout profile: Moderate Characteristics of the Arbidge Soil Contrasting Inclusions Typical profile: Chiara soils on higher lying terraces; Gosinta 0 to 4 inches—brown sandy loam soils on alluvial terraces; soils that are poorly 4 to 15 inches—yellowish brown and light drained or somewhat poorly drained, are yellowish brown sandy clay loam very deep, are loam over clay loam over 15 to 26 inches—very pale brown sandy loam, and are in depressions of terraces; loam barren areas that are 10 to 20 feet in 26 to 40 inches—intermixed layers of diameter and are saline, are shallow and hardpan and very pale brown sandy loam clayey, or are subject to ant activity 40 to 65 inches—multicolored extremely gravelly sand Use and Management Depth class: Moderately deep to a hardpan Major use: Rangeland Drainage class: Well drained Major management factors: Precipitation, salinity, Permeability: Moderately slow hazard of wind erosion Available water capacity: 2.5 to 5.0 inches Dominant vegetation in natural potential plant Potential rooting depth: 20 to 40 inches community: Basin wildrye, black greasewood Runoff: Slow General management considerations: Hazard of water erosion: Slight 32 Soil Survey

Hazard of wind erosion: Moderate Range site: Loamy, 8 to 12 inch precipitation Shrink-swell potential: Moderate zone Contrasting Inclusions Blacknest, Kecko, and Scoon soils on lower lying 8—Arness sandy loam, 2 to 6 percent terraces; Chuska soils on higher lying slopes terraces; Lankbush soils on foot slopes; Udaho soils on hillsides; soils that are Composition moderately deep to a hardpan, are sandy Arness soil and similar inclusions—80 percent loam over sandy clay, and are on terraces; Contrasting inclusions—20 percent barren areas that are 10 to 20 feet in diameter and are saline, are shallow and Setting clayey, or are subject to ant activity Position on landscape: Terraces Use and Management Elevation: 5,100 to 5,900 feet Average annual precipitation: 11 to 13 inches Major uses: Irrigated cropland, rangeland Average annual air temperature: 43 to 46 Major management factors: Precipitation, degrees F permeability, hazard of wind erosion Frost-free season: 90 to 100 days Irrigated Cropland Characteristics of the Arness Soil General management considerations: Typical profile: • Most climatically suited crops can be grown if 0 to 2 inches—grayish brown sandy loam irrigation water is provided. 2 to 6 inches—brown loam • Surface and sprinkler irrigation systems are 6 to 12 inches—brown sandy clay loam suited to this soil. 12 to 19 inches—pale brown sandy clay • Production of irrigated crops is limited by the loam moderately slow permeability and moderate 19 to 32 inches—white fractured lime- and hazard of wind erosion. silica-cemented hardpan • The application of irrigation water should be 32 inches—bedrock adjusted to the intake rate of the soil. Depth class: Shallow to a hardpan • The risk of wind erosion is reduced by Drainage class: Well drained maintaining crop residue on the surface, keeping Permeability: Moderately slow tillage at a minimum, and keeping the surface of Available water capacity: 2.5 to 3.0 inches the soil rough. Potential rooting depth: 14 to 20 inches Rangeland Runoff: Slow Hazard of water erosion: Slight Dominant vegetation in natural potential plant Hazard of wind erosion: Moderate community: Bluebunch wheatgrass, Shrink-swell potential: Moderate Wyoming big sagebrush General management considerations: Contrasting Inclusions • Forage production is limited by low Chuska and Zola soils on lower lying terraces; precipitation. Lud and Mug soils on higher lying terraces; • Seeding is limited by low precipitation and the Tock soils on terraces; soils that are very moderate hazard of wind erosion. shallow to a hardpan, are sandy loam over • Seeding generally is most successful late in sandy clay loam, and are in elevated eroded fall; however, it may not be successful in years areas; areas of Rock outcrop; areas of when precipitation is below average during the blowout growing season. Interpretive Groups Use and Management Land capability classification: IIIe, irrigated, and Major use: Rangeland VIs, nonirrigated Major management factors: Precipitation, depth Jerome-Twin Falls, Idaho 33

to the hardpan, available water capacity, 0 to 6 inches—light gray silty clay hazard of wind erosion 6 to 24 inches—pale brown silty clay loam Dominant vegetation in natural potential plant 24 to 40 inches—brown silt loam community: Bluebunch wheatgrass, basin big 40 to 60 inches—pale brown silty clay loam sagebrush Depth class: Very deep General management considerations: Drainage class: Well drained • Forage production is limited by the low Permeability: Very slow precipitation, shallow rooting depth, and low Available water capacity: 8 to 10 inches available water capacity. Potential rooting depth: 60 inches or more • Seeding is limited by the low precipitation and Runoff: Very rapid moderate hazard of wind erosion. Hazard of water erosion: Very severe • Seeding generally is most successful late in Hazard of wind erosion: Moderate fall; however, it may not be successful in years Shrink-swell potential: High when precipitation is below average during the Salinity throughout profile: Low or moderate growing season. Contrasting Inclusions Interpretive Groups Fathom soils in areas of breaks that have slopes Land capability classification: VIs, nonirrigated of less than 60 percent; Quincy and Rad Range site: Loamy, 11 to 13 inch precipitation soils on terraces; areas of very deep gravelly zone loam on breaks; areas of Rock outcrop Use and Management 9—Badlands-Kudlac association, 30 Major use: Rangeland to 90 percent slopes Major management factors: Precipitation, slope, hazard of water erosion, hazard of wind Composition erosion Dominant vegetation in natural potential plant Badlands and similar inclusions—65 percent community: Kudlac soil—Thurber Kudlac soil and similar inclusions—20 percent needlegrass, Wyoming big sagebrush Contrasting inclusions—15 percent General management considerations: Setting • Most of the available forage is in areas of included soils in and along drainageways. Position on landscape: Badlands—slump areas • Forage production on the Kudlac soil is limited of breaks and areas of breaks that have mainly by low precipitation. slopes of more than 60 percent; Kudlac • The use of forage by livestock is limited by soil—areas of breaks that have slopes of slope. less than 60 percent • Seeding is limited by the low precipitation, Elevation: 2,900 to 3,500 feet slope, very severe hazard of water erosion, and Average annual precipitation: 8 to 10 inches moderate hazard of wind erosion. Average annual air temperature: 49 to 51 degrees F Interpretive Groups Frost-free season: 130 to 140 days Land capability classification: VIIe, nonirrigated Characteristics of Badlands Range site: Loamy, 8 to 10 inch precipitation zone Slope range: 30 to 90 percent Texture: Sandy loam to silty clay Depth to consolidated lake sediment: 0 to 60 10—Bahem silt loam, 1 to 4 percent inches or more slopes Vegetation: None Characteristics of the Kudlac Soil Composition Slope range: 30 to 60 percent Bahem soil and similar inclusions—90 percent Typical profile: Contrasting inclusions—10 percent 34 Soil Survey

Setting 11—Bahem silt loam, 4 to 8 percent Position on landscape: Terraces slopes Elevation: 3,500 to 4,500 feet Average annual precipitation: 8 to 10 inches Composition Average annual air temperature: 48 to 50 Bahem soil and similar inclusions—90 percent degrees F Contrasting inclusions—10 percent Frost-free season: 120 to 140 days Setting Characteristics of the Bahem Soil Position on landscape: Terraces Typical profile: Elevation: 3,500 to 4,500 feet 0 to 8 inches—light brownish gray silt loam Average annual precipitation: 8 to 10 inches 8 to 18 inches—pale brown silt loam Average annual air temperature: 48 to 50 18 to 65 inches—very pale brown silt loam degrees F Depth class: Very deep Frost-free season: 120 to 140 days Drainage class: Well drained Permeability: Moderate Characteristics of the Bahem Soil Available water capacity: 10 to 11 inches Typical profile: Potential rooting depth: 60 inches or more 0 to 9 inches—pale brown silt loam Runoff: Slow 9 to 22 inches—very pale brown silt loam Hazard of water erosion: Slight 22 to 70 inches—pale brown silt loam Hazard of wind erosion: Moderate Depth class: Very deep Contrasting Inclusions Drainage class: Well drained Permeability: Moderate Barrymore, Rad, and Shano soils on lower lying Available water capacity: 10 to 11 inches terraces; Dolman, Sluka, and Taunton soils Potential rooting depth: 60 inches or more on higher lying terraces; Power and Purdam Runoff: Medium soils on terraces; Tulch soils on stream Hazard of water erosion: Moderate terraces; areas of Rock outcrop Hazard of wind erosion: Moderate Use and Management Contrasting Inclusions Major use: Irrigated cropland Kecko, Rad, Shano, and Sluka soils on lower Major management factor: Hazard of wind lying terraces erosion General management considerations: Use and Management • Most climatically suited crops can be grown if Major uses: Rangeland, irrigated cropland irrigation water is provided. Major management factors: Precipitation, slope, • Surface and sprinkler irrigation systems are hazard of water erosion, hazard of wind suited to this soil. erosion • Production of irrigated crops is limited by the moderate hazard of wind erosion. Rangeland • The risk of wind erosion is reduced by Dominant vegetation in natural potential plant maintaining crop residue on the surface, keeping community: Thurber needlegrass, Wyoming tillage at a minimum, and keeping the surface of big sagebrush the soil rough. General management considerations: • Forage production is limited by low Interpretive Groups precipitation. Land capability classification: IIe, irrigated, and • Seeding is limited by low precipitation and the VIc, nonirrigated moderate hazards of water and wind erosion. Jerome-Twin Falls, Idaho 35

• Seeding generally is most successful late in Depth class: Very deep fall; however, it may not be successful in years Drainage class: Well drained when precipitation is below average during the Permeability: Moderate growing season. Available water capacity: 8.5 to 10.0 inches Potential rooting depth: 60 inches or more Irrigated Cropland Runoff: Medium General management considerations: Hazard of water erosion: Moderate • Most climatically suited crops can be grown if Hazard of wind erosion: Moderate irrigation water is provided. Contrasting Inclusions • Sprinkler irrigation is best suited to this soil, but surface irrigation can be used if the water is Sluka soils on lower lying terraces regulated to control erosion. Use and Management • Production of irrigated crops is limited by slope and the moderate hazards of water and wind Major uses: Rangeland, irrigated cropland erosion. Major management factors: Precipitation, slope, • Regulating the application of irrigation water hazard of water erosion, hazard of wind helps to control runoff and erosion. erosion • The risk of wind erosion is reduced by Rangeland maintaining crop residue on the surface, keeping tillage at a minimum, and keeping the surface of Dominant vegetation in natural potential plant the soil rough. community: Thurber needlegrass, Wyoming big sagebrush Interpretive Groups General management considerations: Land capability classification: IIIe, irrigated, and • Forage production is limited by low VIe, nonirrigated precipitation. Range site: Loamy, 8 to 10 inch precipitation • Seeding is limited by low precipitation and the zone moderate hazards of water and wind erosion. • Seeding generally is most successful late in fall; however, it may not be successful in years 12—Bahem silt loam, 8 to 12 percent when precipitation is below average during the slopes growing season. Irrigated Cropland Composition General management considerations: Bahem soil and similar inclusions—95 percent • Because areas of this soil are long and narrow, Contrasting inclusions—5 percent management is dependent on the major uses of Setting the less sloping, wider surrounding areas. Position on landscape: Terraces Interpretive Groups Elevation: 3,500 to 4,500 feet Land capability classification: IVe, irrigated, and Average annual precipitation: 8 to 10 inches VIe, nonirrigated Average annual air temperature: 48 to 50 Range site: Loamy, 8 to 10 inch precipitation degrees F zone Frost-free season: 120 to 140 days

Characteristics of the Bahem Soil 13—Banbury loam, 2 to 12 percent slopes Typical profile: 0 to 10 inches—pale brown silt loam Composition 10 to 28 inches—light gray silt loam 28 to 60 inches—very pale brown very fine Banbury soil and similar inclusions—90 percent sandy loam Contrasting inclusions—10 percent 36 Soil Survey

Setting Rangeland Position on landscape: Terraces Dominant vegetation in natural potential plant Elevation: 3,000 to 4,500 feet community: Bluebunch wheatgrass, Average annual precipitation: 8 to 10 inches Wyoming big sagebrush Average annual air temperature: 49 to 51 General management considerations: degrees F • Forage production is limited by low Frost-free season: 120 to 140 days precipitation, low available water capacity, and shallow rooting depth. Characteristics of the Banbury Soil • Seeding is limited by the low precipitation and Typical profile: moderate hazard of water erosion. 0 to 5 inches—dark grayish brown and • Seeding generally is most successful late in brown loam fall; however, it may not be successful in years 5 to 17 inches—brown loam when precipitation is below average during the 17 to 19 inches—fractured bedrock growing season. 19 inches—bedrock Interpretive Groups Depth class: Shallow to bedrock Drainage class: Well drained Land capability classification: IVe, irrigated, and Permeability: Moderate VIe, nonirrigated Available water capacity: 2.0 to 3.5 inches Range site: Shallow loamy, 8 to 12 inch Potential rooting depth: 10 to 20 inches precipitation zone Runoff: Medium Hazard of water erosion: Moderate Shrink-swell potential: Moderate 14—Banbury loam, 12 to 20 percent slopes Contrasting Inclusions Kecko, Paulville, and Taunton soils on lower lying Composition terraces and on the sides of terraces; soils Banbury soil and similar inclusions—90 percent that are poorly drained, are shallow to Contrasting inclusions—10 percent bedrock, are loam over clay loam, and are in depressional areas of terraces; barren areas Setting that are 10 to 20 feet in diameter and are Position on landscape: Terraces saline, are shallow and clayey, or are subject Elevation: 3,000 to 3,500 feet to ant activity Average annual precipitation: 8 to 10 inches Use and Management Average annual air temperature: 49 to 51 degrees F Major uses: Hayland and pastureland, rangeland Frost-free season: 130 to 140 days Major management factors: Precipitation, slope, depth to bedrock, available water capacity, Characteristics of the Banbury Soil hazard of water erosion Typical profile: Hayland and Pastureland 0 to 2 inches—light brownish gray loam General management considerations: 2 to 4 inches—light brownish gray clay loam • Most climatically suited grasses and legumes 4 to 12 inches—light brownish gray loam can be grown if irrigation water is provided. 12 inches—bedrock • Sprinkler irrigation is best suited to this soil, but Depth class: Shallow to bedrock surface irrigation can be used if the water is Drainage class: Well drained regulated to control erosion. Permeability: Moderate • Production of forage is limited by slope, Available water capacity: 2.0 to 3.5 inches shallow rooting depth, and low available water Potential rooting depth: 10 to 20 inches capacity. Runoff: Medium • Regulating the application of irrigation water Hazard of water erosion: Moderate helps to control runoff and erosion. Shrink-swell potential: Moderate Jerome-Twin Falls, Idaho 37

Contrasting Inclusions Characteristics of the Banbury Soil Bluegulch soils on ridges and dip slopes; Kecko Typical profile: soils on lower lying terraces; areas of loam 0 to 4 inches—pale brown loam that are shallow to bedrock, are poorly 4 to 12 inches—pale brown loam drained, and are in slumps; areas of Rock 12 inches—bedrock outcrop Depth class: Shallow to bedrock Drainage class: Well drained Use and Management Permeability: Moderate Major use: Rangeland Available water capacity: 2.0 to 3.5 inches Major management factors: Precipitation, depth Potential rooting depth: 10 to 20 inches to bedrock, available water capacity, hazard Runoff: Medium of water erosion Hazard of water erosion: Moderate Dominant vegetation in natural potential plant Shrink-swell potential: Moderate community: Bluebunch wheatgrass, Characteristics of the Rock Outcrop Wyoming big sagebrush General management considerations: Kind of rock: Exposed basalt • Forage production is limited by low Description of areas: Sharp, angular to precipitation, shallow rooting depth, and low semirounded, long, narrow lava flow available water capacity. pressure ridges ranging to a semirounded • Seeding is limited by low precipitation and the area that extends 1 foot to 10 feet above the moderate hazard of water erosion. adjacent landscape. • Seeding generally is most successful late in fall; however, it may not be successful in years Contrasting Inclusions when precipitation is below average during the Barrymore soils on terraces; Kecko, Paulville, growing season. Suepert, and Taunton soils on lower lying Interpretive Groups terraces; saline, somewhat poorly drained loam that is shallow to bedrock and is in Land capability classification: VIe, nonirrigated depressional areas of terraces Range site: Shallow loamy, 8 to 12 inch precipitation zone Use and Management

15—Banbury-Rock outcrop complex, Major use: Rangeland 2 to 20 percent slopes Major management factors: Precipitation, depth to bedrock, available water capacity, areas of Rock outcrop, hazard of water erosion Composition Dominant vegetation in natural potential plant Banbury soil and similar inclusions—55 percent community: Banbury soil—bluebunch Rock outcrop—35 percent wheatgrass, Wyoming big sagebrush Contrasting inclusions—10 percent General management considerations: • Forage production is limited by low Setting precipitation, shallow rooting depth, and low Position on landscape: Terraces available water capacity. Elevation: 3,000 to 4,500 feet • Seeding is limited by the low precipitation, Average annual precipitation: 8 to 10 inches areas of Rock outcrop, and moderate hazard of Average annual air temperature: 49 to 51 water erosion. degrees F • The use of equipment is limited by the areas of Frost-free season: 120 to 140 days Rock outcrop. 38 Soil Survey

Interpretive Groups silica-cemented hardpan 51 inches—bedrock Land capability classification: VIIs, nonirrigated Depth class: Moderately deep to a hardpan Range site: Banbury soil—Shallow loamy, 8 to 12 Drainage class: Well drained inch precipitation zone Permeability: Slow Available water capacity: 3.5 to 6.5 inches 16—Bancy-Tanner complex, 2 to 12 Potential rooting depth: 20 to 40 inches percent slopes Runoff: Medium Hazard of water erosion: Moderate Shrink-swell potential: High Composition Contrasting Inclusions Bancy soil and similar inclusions—60 percent Tanner soil and similar inclusions—30 percent Aninto, Chayson, and Oshone soils in convex Contrasting inclusions—10 percent areas of terraces Setting Use and Management Position on landscape: Bancy soil—concave to Major use: Rangeland plane areas of terraces; Tanner soil—convex Major management factors: Depth to clayey areas of terraces subsoil, available water capacity, hazard of Elevation: 5,500 to 6,000 feet water erosion Average annual precipitation: 12 to 16 inches Dominant vegetation in natural potential plant Average annual air temperature: 42 to 44 community: Bancy soil—Idaho fescue, low degrees F sagebrush; Tanner soil—bluebunch Frost-free season: 90 to 100 days wheatgrass, basin big sagebrush General management considerations: Characteristics of the Bancy Soil • Forage production is limited by the shallow Slope range: 2 to 12 percent rooting depth and low available water capacity of Typical profile: the Bancy soil. 0 to 3 inches—brown gravelly clay loam • Rooting depth is limited to the upper part of the 3 to 8 inches—brown clay Bancy soil because of the claypan. 8 to 17 inches—yellowish brown clay • Seeding is limited by the moderate hazard of 17 to 31 inches—white lime- and silica- water erosion. cemented hardpan Interpretive Groups 31 inches—fractured bedrock Depth class: Shallow to a hardpan Land capability classification: VIIs, nonirrigated Drainage class: Well drained Range site: Bancy soil—Shallow claypan, 12 to Permeability: Slow 16 inch precipitation zone; Tanner soil— Available water capacity: 2 to 3 inches Loamy, 11 to 13 inch precipitation zone Potential rooting depth: 14 to 20 inches Runoff: Medium Hazard of water erosion: Moderate 17—Barrymore silt loam, 1 to 4 Shrink-swell potential: High percent slopes

Characteristics of the Tanner Soil Composition Slope range: 2 to 10 percent Barrymore soil and similar inclusions—85 Typical profile: percent 0 to 3 inches—brown silt loam Contrasting inclusions—15 percent 3 to 16 inches—brown silty clay loam Setting 16 to 22 inches—brown silty clay 22 to 35 inches—pale brown gravelly loam Position on landscape: Terraces 35 to 51 inches—white fractured lime- and Elevation: 3,500 to 4,000 feet Jerome-Twin Falls, Idaho 39

Average annual precipitation: 9 to 11 inches Average annual precipitation: 9 to 11 inches Average annual air temperature: 47 to 49 Average annual air temperature: 47 to 49 degrees F degrees F Frost-free season: 130 to 140 days Frost-free season: 130 to 140 days Characteristics of the Barrymore Soil Characteristics of the Barrymore Soil Typical profile: Typical profile: 0 to 8 inches—pale brown silt loam 0 to 5 inches—yellowish brown silt loam 8 to 16 inches—pale brown silt loam 5 to 17 inches—yellowish brown silt loam 16 to 26 inches—very pale brown silt loam 17 to 25 inches—very pale brown silt loam 26 inches—bedrock 25 inches—fractured bedrock Depth class: Moderately deep to bedrock Depth class: Moderately deep to bedrock Drainage class: Well drained Drainage class: Well drained Permeability: Moderate Permeability: Moderate Available water capacity: 5.0 to 7.5 inches Available water capacity: 5.0 to 8.5 inches Potential rooting depth: 20 to 40 inches Potential rooting depth: 20 to 40 inches Runoff: Slow Runoff: Slow Hazard of water erosion: Slight Hazard of water erosion: Slight Contrasting Inclusions Characteristics of the Starbuck Soil Dolman and McCain soils on higher lying Typical profile: terraces; Shano soils on lower lying terraces; 0 to 5 inches—yellowish brown silt loam Starbuck soils on terraces; areas of Rock 5 to 18 inches—yellowish brown and light outcrop yellowish brown silt loam 18 inches—fractured bedrock Use and Management Depth class: Shallow to bedrock Major use: Irrigated cropland Drainage class: Well drained Major management factors: None Permeability: Moderate General management considerations: Available water capacity: 2.5 to 3.5 inches • Most climatically suited crops can be grown if Potential rooting depth: 12 to 20 inches irrigation water is provided. Runoff: Slow • Surface and sprinkler irrigation systems are Hazard of water erosion: Slight suited to this soil. Contrasting Inclusions Interpretive Groups Hoosegow, McCain, Minveno, Power, and Land capability classification: IIIe, irrigated, and Taunton soils on higher lying terraces; VIs, nonirrigated Owinza soils in depressional areas of terraces; Rad soils on lower lying terraces; areas of Rock outcrop 18—Barrymore-Starbuck complex, 1 to 4 percent slopes Use and Management Major uses: Rangeland, irrigated cropland Major management factors: Precipitation of both Composition soils, depth to bedrock and available water Barrymore soil and similar inclusions—50 capacity of the Starbuck soil percent Starbuck soil and similar inclusions—30 percent Rangeland Contrasting inclusions—20 percent Dominant vegetation in natural potential plant community: Barrymore soil—Thurber Setting needlegrass, Wyoming big sagebrush; Position on landscape: Terraces Starbuck soil—bluebunch wheatgrass, Elevation: 3,500 to 4,000 feet Wyoming big sagebrush 40 Soil Survey

General management considerations: Depth class: Deep to bedrock • Forage production is mainly limited by low Drainage class: Well drained precipitation and by the shallow rooting depth Permeability: Moderate and low available water capacity of the Starbuck Available water capacity: 3.5 to 5.0 inches soil. Potential rooting depth: 40 to 60 inches • Seeding is limited by the low precipitation. Runoff: Medium • Seeding generally is most successful late in Hazard of water erosion: Moderate fall; however, it may not be successful in years Contrasting Inclusions when precipitation is below average during the growing season. Bahem, Rakane, and Trevino soils on lower lying terraces; soils that are moderately deep to Irrigated Cropland bedrock, are gravelly loam over very gravelly General management considerations: loam, and are on dip slopes and ridges; • Most climatically suited crops can be grown if areas of Rock outcrop irrigation water is provided. Use and Management • Surface and sprinkler irrigation systems are suited to the soils in this unit. Major uses: Rangeland, irrigated cropland • Production of irrigated crops is limited by the Major management factors: Precipitation, slope, shallow rooting depth and low available water hazard of water erosion capacity of the Starbuck soil. Rangeland Interpretive Groups Dominant vegetation in natural potential plant Land capability classification: IIIe, irrigated, and community: Thurber needlegrass, Wyoming VIc, nonirrigated big sagebrush Range site: Barrymore soil—Loamy, 8 to 10 inch General management considerations: precipitation zone; Starbuck soil—Shallow • Forage production is limited by low loamy, 8 to 12 inch precipitation zone precipitation. • Seeding is limited by low precipitation, slope, 19—Bluegulch gravelly loam, 2 to 12 and the moderate hazard of water erosion. percent slopes • Seeding generally is most successful late in fall; however, it may not be successful in years Composition when precipitation is below average during the growing season. Bluegulch soil and similar inclusions—80 percent Contrasting inclusions—20 percent Irrigated Cropland Setting General management considerations: Position on landscape: Dip slopes, ridges • Most climatically suited crops can be grown if Elevation: 3,500 to 4,000 feet irrigation water is provided. Average annual precipitation: 8 to 10 inches • Sprinkler irrigation is best suited to this soil, but Average annual air temperature: 49 to 51 surface irrigation can be used if the water is degrees F regulated to control erosion. Frost-free season: 120 to 140 days • Production of irrigated crops is limited by slope and the moderate hazard of water erosion. Characteristics of the Bluegulch Soil • Regulating irrigation water helps to control Typical profile: runoff and erosion. 0 to 4 inches—brown gravelly loam 4 to 12 inches—pale brown gravelly loam Interpretive Groups 12 to 20 inches—pale brown very gravelly loam Land capability classification: IVe, irrigated, and 20 to 44 inches—light gray extremely VIe, nonirrigated gravelly sandy loam Range site: Loamy, 8 to 10 inch precipitation 44 inches—bedrock zone Jerome-Twin Falls, Idaho 41

20—Bluegulch-Rock outcrop Dominant vegetation in natural potential plant complex, 2 to 30 percent slopes community: Bluegulch soil—Thurber needlegrass, Wyoming big sagebrush General management considerations: Composition • Forage production is limited by low Bluegulch soil and similar inclusions—60 percent precipitation. Rock outcrop—25 percent • Seeding is limited by low precipitation, the Contrasting inclusions—15 percent moderate hazard of water erosion, and the areas of Rock outcrop. Setting • The use of equipment is limited by the areas of Position on landscape: Dip slopes, ridges Rock outcrop. Elevation: 3,500 to 4,000 feet Interpretive Groups Average annual precipitation: 8 to 10 inches Average annual air temperature: 49 to 51 Land capability classification: VIIe, nonirrigated degrees F Range site: Bluegulch soil—Loamy, 8 to 10 inch Frost-free season: 120 to 140 days precipitation zone Characteristics of the Bluegulch Soil Typical profile: 21—Brose-Amboat complex, 2 to 20 0 to 6 inches—light brownish gray gravelly percent slopes loam 6 to 13 inches—pale brown gravelly loam Composition 13 to 19 inches—pale brown very gravelly Brose soil and similar inclusions—55 percent loam Amboat soil and similar inclusions—35 percent 19 to 48 inches—very pale brown extremely Contrasting inclusions—10 percent gravelly sandy loam 48 inches—bedrock Setting Depth class: Deep to bedrock Position on landscape: Summits (fig. 6) Drainage class: Well drained Permeability: Moderate Available water capacity: 3.5 to 5.0 inches Potential rooting depth: 40 to 60 inches Runoff: Medium Hazard of water erosion: Moderate Characteristics of the Rock Outcrop Kind of rock: Exposed welded tuff Description of areas: Sharp, angular to semirounded, long, narrow ridges ranging to a semirounded area that extends 1 foot to 10 feet above the adjacent landscape Contrasting Inclusions Banbury and Bahem soils on lower lying terraces; soils that are moderately deep to bedrock, are gravelly loam over very gravelly loam, and are on ridges and dip slopes Figure 6.—Area of Brose-Amboat complex, 2 to 20 Use and Management percent slopes. Brose soil in foreground and Amboat soil in background. Major use: Rangeland Major management factors: Precipitation, hazard Elevation: 5,800 to 6,600 feet of water erosion, areas of Rock outcrop Average annual precipitation: 12 to 16 inches 42 Soil Survey

Average annual air temperature: 40 to 44 Dominant vegetation in natural potential plant degrees F community: Brose soil—Idaho fescue, low Frost-free season: 70 to 90 days sagebrush; Amboat soil—Idaho fescue, mountain big sagebrush Characteristics of the Brose Soil General management considerations: Typical profile: • Forage production is limited by the shallow 0 to 1 inch—brown extremely cobbly loam rooting depth and low available water capacity of 1 inch to 3 inches—brown gravelly loam the Brose soil. 3 to 9 inches—brown gravelly clay loam • Seeding is limited by the rock fragments in the 9 to 18 inches—brown and reddish brown surface layer of the Brose soil and by the gravelly clay moderate hazard of water erosion on the Amboat 18 inches—bedrock and Brose soils. Depth class: Shallow to bedrock Interpretive Groups Drainage class: Well drained Permeability: Very slow Land capability classification: VIIs, nonirrigated Available water capacity: 1.5 to 3.0 inches Range site: Brose soil—Shallow claypan, 12 to Potential rooting depth: 10 to 20 inches 16 inch precipitation zone; Amboat soil— Runoff: Medium Stony loam, 12 to 16 inch precipitation zone Hazard of water erosion: Moderate Shrink-swell potential: High 22—Budlewis cobbly silt loam, 2 to 6 Characteristics of the Amboat Soil percent slopes Typical profile: 0 to 8 inches—dark brown gravelly loam Composition 8 to 17 inches—dark brown gravelly clay Budlewis soil and similar inclusions—85 percent 17 to 60 inches—brown extremely stony clay Contrasting inclusions—15 percent Depth class: Very deep Drainage class: Well drained Setting Permeability: Very slow Position on landscape: Terraces Available water capacity: 3.0 to 4.5 inches Elevation: 5,300 to 6,000 feet Potential rooting depth: 60 inches or more Average annual precipitation: 12 to 15 inches Runoff: Medium Average annual air temperature: 43 to 46 Hazard of water erosion: Moderate degrees F Shrink-swell potential: High Frost-free season: 90 to 100 days Contrasting Inclusions Characteristics of the Budlewis Soil Congle soils on foot slopes; Doodlelink and Eep soils on hill slopes and breaks; Oshone soils Typical profile: on lower lying terraces; soils that are very 0 to 5 inches—grayish brown cobbly silt loam shallow to bedrock, are extremely cobbly 5 to 11 inches—brown silty clay loam loam over gravelly clay, and are on ledges 11 to 21 inches—pale brown clay bordering scarp faces; areas of Rock outcrop 21 to 22 inches—white lime- and silica- cemented hardpan Use and Management 22 inches—fractured bedrock Major use: Rangeland Depth class: Moderately deep to a hardpan Major management factors: Brose soil—depth to Drainage class: Well drained bedrock, available water capacity, rock Permeability: Slow fragments in the surface layer, hazard of Available water capacity: 5 to 7 inches water erosion; Amboat soil—hazard of water Potential rooting depth: 20 to 39 inches erosion Runoff: Medium Jerome-Twin Falls, Idaho 43

Hazard of water erosion: Moderate 3 to 10 inches—brown silty clay loam Shrink-swell potential: High 10 to 21 inches—pale brown clay 21 to 26 inches—light yellowish brown clay Contrasting Inclusions loam Chayson, Howcree, and Tanner soils on higher 26 to 38 inches—white lime- and silica- lying terraces; soils that are very shallow to a cemented hardpan hardpan, are very cobbly silt loam over clay, 38 inches—bedrock and are on lower lying terraces Depth class: Moderately deep to a hardpan Drainage class: Well drained Use and Management Permeability: Slow Major use: Rangeland Available water capacity: 5 to 7 inches Major management factors: Depth to the clayey Potential rooting depth: 20 to 39 inches subsoil, hazard of water erosion Runoff: Medium Dominant vegetation in natural potential plant Hazard of water erosion: Moderate community: Idaho fescue, low sagebrush Shrink-swell potential: High General management considerations: Characteristics of the Chayson Soil • Forage production is limited by the shallow rooting depth. Typical profile: • Plant rooting depth is limited to the upper part 0 to 4 inches—dark grayish brown loam of the soil because of the claypan. 4 to 22 inches—grayish brown and brown • Seeding is limited by the moderate hazard of clay loam water erosion. 22 to 29 inches—very pale brown gravelly loam Interpretive Groups 29 to 60 inches—white lime- and silica- Land capability classification: IVs, nonirrigated cemented hardpan Range site: Shallow claypan, 12 to 16 inch Depth class: Moderately deep to a hardpan precipitation zone Drainage class: Well drained Permeability: Moderately slow Available water capacity: 4 to 6 inches 23—Budlewis-Chayson complex, 2 to Potential rooting depth: 20 to 40 inches 6 percent slopes Runoff: Medium Hazard of water erosion: Moderate Composition Shrink-swell potential: Moderate Budlewis soil and similar inclusions—60 percent Contrasting Inclusions Chayson soil and similar inclusions—30 percent Brose soils on summits; Howcree soils in Contrasting inclusions—10 percent concave to plane areas of terraces, Tanner Setting soils on lower lying terraces; soils that are shallow to a hardpan, are very cobbly silt Position on landscape: Budlewis soil—concave loam over silty clay, and are on lower lying to plane areas of terraces; Chayson soil— terraces; soils that are shallow to bedrock, convex areas of terraces are silt loam over silty clay, and are on higher Elevation: 5,300 to 6,000 feet lying terraces Average annual precipitation: 12 to 16 inches Average annual air temperature: 41 to 46 Use and Management degrees F Frost-free season: 90 to 100 days Major use: Rangeland Major management factors: Budlewis soil—depth Characteristics of the Budlewis Soil to the clayey subsoil, hazard of water Typical profile: erosion; Chayson soil—hazard of water 0 to 3 inches—grayish brown silt loam erosion 44 Soil Survey

Dominant vegetation in natural potential plant Permeability: Slow community: Budlewis soil—Idaho fescue, low Available water capacity: 5 to 7 inches sagebrush; Chayson soil—Idaho fescue, Potential rooting depth: 20 to 39 inches mountain big sagebrush Runoff: Medium General management considerations: Hazard of water erosion: Moderate • Forage production is limited by the shallow Shrink-swell potential: High rooting depth of the Budlewis soil. Characteristics of the Tanner Soil • Plant rooting depth is limited to the upper part of the Budlewis soil because of the claypan. Typical profile: • Seeding is limited by the moderate hazard of 0 to 3 inches—brown silt loam water erosion. 3 to 16 inches—grayish brown or brown silty clay loam Interpretive Groups 16 to 22 inches—pale brown silty clay Land capability classification: IVs, nonirrigated 22 to 35 inches—very pale brown gravelly Range site: Budlewis soil—Shallow claypan, 12 loam to 16 inch precipitation zone; Chayson soil— 35 to 51 inches—white fractured lime- and Loamy, 13 to 16 inch precipitation zone silica-cemented hardpan 51 inches—bedrock Depth class: Moderately deep to a hardpan 24—Budlewis-Tanner complex, 2 to 6 Drainage class: Well drained percent slopes Permeability: Slow Available water capacity: 3.5 to 6.5 inches Composition Potential rooting depth: 20 to 40 inches Runoff: Medium Budlewis soil and similar inclusions—60 percent Hazard of water erosion: Moderate Tanner soil and similar inclusions—30 percent Shrink-swell potential: High Contrasting inclusions—10 percent Contrasting Inclusions Setting Chayson, Howcree, and Iwica soils on higher Position on landscape: Budlewis soil—concave lying terraces; soils that are shallow to a areas of terraces; Tanner soil—convex areas duripan, are very cobbly sandy loam over of terraces very gravelly sandy clay loam, and are on Elevation: 5,300 to 6,000 feet higher lying terraces; soils that are shallow to Average annual precipitation: 12 to 14 inches bedrock, are very gravelly loam over Average annual air temperature: 43 to 46 extremely gravelly clay, and are in concave degrees F areas of terraces; soils that are moderately Frost-free season: 90 to 100 days deep to a hardpan, are silt loam over silty clay loam, and are in convex areas of Characteristics of the Budlewis Soil terraces Typical profile: Use and Management 0 to 4 inches—brown silt loam 4 to 11 inches—grayish brown silty clay loam Major use: Rangeland 11 to 19 inches—pale brown silty clay Major management factors: Budlewis soil—depth 19 to 27 inches—very pale brown silty clay to the clayey subsoil, hazard of water loam erosion; Tanner soil—hazard of water 27 to 31 inches—pale brown silty clay loam erosion 31 to 36 inches—white lime- and silica- Dominant vegetation in natural potential plant cemented hardpan community: Budlewis soil—Idaho fescue, low 36 inches—bedrock sagebrush; Tanner soil—bluebunch Depth class: Moderately deep to a hardpan wheatgrass, basin big sagebrush Drainage class: Well drained General management considerations: Jerome-Twin Falls, Idaho 45

• Forage production is limited by the shallow Use and Management rooting depth of the Budlewis soil. Major uses: Rangeland, irrigated cropland • Plant rooting depth is limited to the upper part Major management factors: Precipitation, depth of the Budlewis soil because of the claypan. to the hardpan, available water capacity, • Seeding is limited by the moderate hazard of hazard of water erosion, slope water erosion. Rangeland Interpretive Groups Dominant vegetation in natural potential plant Land capability classification: IVs, nonirrigated community: Thurber needlegrass, Wyoming Range site: Budlewis soil—Shallow claypan, 12 big sagebrush to 16 inch precipitation zone; Tanner soil— General management considerations: Loamy, 11 to 13 inch precipitation zone • Forage production is limited by the low precipitation, shallow rooting depth, and low 25—Chiara silt loam, 1 to 8 percent available water capacity. slopes • Seeding is limited by the low precipitation and moderate hazard of water erosion. • Seeding generally is most successful late in Composition fall; however, it may not be successful in years Chiara soil and similar inclusions—85 percent when precipitation is below average during the Contrasting inclusions—15 percent growing season. Setting Irrigated Cropland Position on landscape: Terraces General management considerations: Elevation: 3,600 to 4,500 feet • Most climatically suited crops can be grown if Average annual precipitation: 8 to 10 inches irrigation water is provided. Average annual air temperature: 47 to 49 • Sprinkler irrigation is best suited to this soil, but degrees F surface irrigation can be used if the water is Frost-free season: 120 to 130 days regulated to control erosion. • Production of irrigated crops is limited by the Characteristics of the Chiara Soil shallow rooting depth, low available water Typical profile: capacity, and moderate hazard of water erosion. 0 to 3 inches—pale brown silt loam Interpretive Groups 3 to 9 inches—light yellowish brown silt loam 9 to 17 inches—white silt loam Land capability classification: IVe, irrigated, and 17 to 49 inches—white lime- and silica- VIs, nonirrigated cemented hardpan Range site: Loamy, 8 to 10 inch precipitation Depth class: Shallow to a hardpan zone Drainage class: Well drained Permeability: Moderate Available water capacity: 2 to 4 inches 26—Chuska loam, 1 to 10 percent Potential rooting depth: 10 to 20 inches slopes Runoff: Medium Hazard of water erosion: Moderate Composition Chuska soil and similar inclusions—85 percent Contrasting Inclusions Contrasting inclusions—15 percent Bahem and Rad soils on lower lying terraces; Setting Chuska, Colthorp, and Roseworth soils on higher lying terraces; Dolman, Portneuf, and Position on landscape: Terraces Sluka soils on terraces; Tulch soils on stream Elevation: 3,500 to 5,000 feet terraces; areas of Rock outcrop Average annual precipitation: 9 to 10 inches 46 Soil Survey

Average annual air temperature: 49 to 51 • Sprinkler irrigation is best suited to this soil, but degrees F surface irrigation can be used if the water is Frost-free season: 110 to 140 days regulated to control erosion. • Because of the moderately slow permeability, Characteristics of the Chuska Soil the application of irrigation water should be Typical profile: adjusted to the water intake rate. 0 to 3 inches—pale brown loam • Production of irrigated crops is limited by the 3 to 10 inches—very pale brown gravelly shallow rooting depth, low available water loam capacity, slope, and moderate hazard of water 10 to 16 inches—very pale brown very erosion. gravelly loam Interpretive Groups 16 to 60 inches—white lime- and silica- cemented hardpan Land capability classification: IVe, irrigated, and Depth class: Shallow to a hardpan VIs, nonirrigated Drainage class: Well drained Range site: Loamy, 8 to 10 inch precipitation Permeability: Moderately slow zone Available water capacity: 2 to 3 inches Potential rooting depth: 12 to 20 inches 27—Chuska gravelly loam, 2 to 12 Runoff: Medium percent slopes Hazard of water erosion: Moderate Shrink-swell potential: Moderate Composition Contrasting Inclusions Chuska soil and similar inclusions—85 percent Contrasting inclusions—15 percent Blacknest soils on higher lying terraces, Bluegulch soils on dip slopes and ridges, Setting Dolman soils on terraces Position on landscape: Terraces, dip slopes, ridges Use and Management Elevation: 4,500 to 5,700 feet Major uses: Rangeland, irrigated cropland Average annual precipitation: 9 to 12 inches Major management factors: Precipitation, depth Average annual air temperature: 46 to 49 to the hardpan, available water capacity, degrees F permeability, slope, hazard of water erosion Frost-free season: 100 to 120 days Rangeland Characteristics of the Chuska Soil Dominant vegetation in natural potential plant Typical profile: community: Thurber needlegrass, Wyoming 0 to 3 inches—pale brown gravelly loam big sagebrush 3 to 10 inches—pale brown clay loam General management considerations: 10 to 14 inches—very pale brown gravelly • Forage production is limited by the low clay loam precipitation, shallow rooting depth, and low 14 to 18 inches—white lime- and silica- available water capacity. cemented hardpan • Seeding is limited by low precipitation and the 18 to 51 inches—very pale brown extremely moderate hazard of water erosion. gravelly sandy loam • Seeding generally is most successful late in 51 inches—bedrock fall; however, it may not be successful in years Depth class: Shallow to a hardpan when precipitation is below average during the Drainage class: Well drained growing season. Permeability: Moderately slow Available water capacity: 2 to 3 inches Irrigated Cropland Potential rooting depth: 12 to 20 inches General management considerations: Runoff: Medium • Most climatically suited crops can be grown if Hazard of water erosion: Moderate irrigation water is provided. Shrink-swell potential: Moderate Jerome-Twin Falls, Idaho 47

Contrasting Inclusions Interpretive Groups Ackett soils on stream terraces; Arbidge, Land capability classification: VIs, nonirrigated, Lankbush, and Rogerson soils on lower lying and IVe, irrigated terraces; Nawt and Stricker soils on breaks; Range site: Loamy, 8 to 12 inch precipitation soils that are shallow to a hardpan, are loam zone underlain by sand and gravel, and are on terraces; soils that are moderately deep to a 28—Chuska very stony loam, 2 to 12 hardpan, are gravelly loam over gravelly clay percent slopes loam, and are on terraces; areas of Rock outcrop; barren areas that are 10 to 20 feet Composition in diameter and are saline, are shallow and clayey, or are subject to ant activity Chuska soil and similar inclusions—85 percent Contrasting inclusions—15 percent Use and Management Setting Major uses: Rangeland, irrigated cropland Major management factors: Precipitation, depth Position on landscape: Terraces and ridges to the hardpan, available water capacity, Elevation: 4,500 to 5,400 feet permeability, slope, hazard of water erosion Average annual precipitation: 9 to 12 inches Average annual air temperature: 46 to 49 Rangeland degrees F Dominant vegetation in natural potential plant Frost-free season: 110 to 120 days community: Bluebunch wheatgrass, Characteristics of the Chuska Soil Wyoming big sagebrush General management considerations: Typical profile: • Forage production is limited by low 0 to 3 inches—pale brown very stony loam precipitation, shallow rooting depth, and low 3 to 10 inches—brown clay loam available water capacity. 10 to 16 inches—very pale brown sandy clay • Seeding is limited by low precipitation and the loam moderate hazard of water erosion. 16 to 28 inches—white lime- and silica- • Seeding generally is most successful late in cemented hardpan fall; however, it may not be successful in years 28 to 45 inches—very pale brown extremely when precipitation is below average during the stony sandy loam growing season. 45 inches—bedrock Depth class: Shallow to a hardpan Irrigated Cropland Drainage class: Well drained General management considerations: Permeability: Moderately slow • Most climatically suited crops can be grown if Available water capacity: 2 to 3 inches irrigation water is provided. Potential rooting depth: 12 to 20 inches • Sprinkler irrigation is best suited to this soil, but Runoff: Medium surface irrigation can be used if the water is Hazard of water erosion: Moderate regulated to control erosion. Shrink-swell potential: Moderate • Because of the moderately slow permeability, Contrasting Inclusions the application of irrigation water should be adjusted to the water intake rate. Ackett soils on stream terraces; Chiara soils on • Production of irrigated crops is limited by the lower lying terraces; soils that are very shallow rooting depth, low available water shallow to a hardpan, are very stony loam capacity, slope, and moderate hazard of water over clay loam, and are on ridges; soils that erosion. are moderately deep to a hardpan, are 48 Soil Survey

gravelly loam over gravelly clay loam, and 24 inches—bedrock are on terraces; barren areas that are 10 to Depth class: Shallow to a hardpan 20 feet in diameter and are saline, are Drainage class: Well drained shallow and clayey, or are subject to ant Permeability: Moderately slow activity Available water capacity: 2.0 to 3.5 inches Potential rooting depth: 10 to 20 inches Use and Management Runoff: Slow Major use: Rangeland Hazard of water erosion: Slight Major management factors: Precipitation, depth Contrasting Inclusions to the hardpan, available water capacity, rock fragments in the surface layer, hazard of Chiara and Scoon soils on lower lying terraces, water erosion Chuska soils on higher lying terraces, areas Dominant vegetation in natural potential plant of Rock outcrop community: Bluebunch wheatgrass, Use and Management Wyoming big sagebrush General management considerations: Major uses: Rangeland, irrigated cropland • Forage production is limited by the low Major management factors: Precipitation, depth precipitation, shallow rooting depth, and low to the hardpan, available water capacity, available water capacity. permeability • Seeding is limited by the low precipitation, rock Rangeland fragments in the surface layer, and moderate hazard of water erosion. Dominant vegetation in natural potential plant community: Thurber needlegrass, Wyoming Interpretive Groups big sagebrush Land capability classification: VIIs, nonirrigated General management considerations: Range site: Loamy, 8 to 12 inch precipitation • Forage production is limited by the low zone precipitation, shallow rooting depth, and low available water capacity. • Seeding is limited by low precipitation. 29—Colthorp cobbly silt loam, 1 to 4 • Seeding generally is most successful late in percent slopes fall; however, it may not be successful in years of below average precipitation during the growing Composition season. Colthorp soil and similar inclusions—85 percent Irrigated Cropland Contrasting inclusions—15 percent General management considerations: Setting • Most climatically suited crops can be grown if irrigation water is provided. Position on landscape: Terraces • Surface and sprinkler irrigation systems are Elevation: 4,200 to 4,700 feet suited to this soil. Average annual precipitation: 9 to 10 inches • Because of the moderately slow permeability, Average annual air temperature: 49 to 51 the application of irrigation water should be degrees F adjusted to the water intake rate. Frost-free season: 110 to 120 days • Production of irrigated crops is limited by the Characteristics of the Colthorp Soil shallow rooting depth and low available water capacity. Typical profile: 0 to 3 inches—pale brown cobbly silt loam Interpretive Groups 3 to 11 inches—very pale brown silt loam 11 to 18 inches—very pale brown gravelly Land capability classification: IVs, irrigated, and silt loam VIs, nonirrigated 18 to 24 inches—white lime- and silica- Range site: Loamy, 8 to 10 inch precipitation cemented hardpan zone Jerome-Twin Falls, Idaho 49

30—Colthorp very cobbly silt loam, 1 precipitation, shallow rooting depth, and low to 15 percent slopes available water capacity. • Seeding is limited by the low precipitation and rock fragments in the surface layer. Composition Interpretive Groups Colthorp soil and similar inclusions—90 percent Contrasting inclusions—10 percent Land capability classification: VIIs, nonirrigated Range site: Loamy, 8 to 10 inch precipitation Setting zone Position on landscape: Terraces Elevation: 4,200 to 4,700 feet Average annual precipitation: 9 to 10 inches 31—Congle gravelly loam, 8 to 30 Average annual air temperature: 49 to 51 percent slopes degrees F Frost-free season: 110 to 120 days Composition Characteristics of the Colthorp Soil Congle soil and similar inclusions—85 percent Contrasting inclusions—15 percent Typical profile: 0 to 4 inches—light brownish gray very Setting cobbly silt loam Position on landscape: Back slopes and foot 4 to 9 inches—pale brown silt loam slopes 9 to 19 inches—light brownish gray gravelly Elevation: 4,800 to 6,400 feet silt loam Average annual precipitation: 13 to 20 inches 19 to 28 inches—white lime- and silica- Average annual air temperature: 42 to 45 cemented hardpan degrees F 28 inches—bedrock Frost-free season: 80 to 100 days Depth class: Shallow to a hardpan Drainage class: Well drained Characteristics of the Congle Soil Permeability: Moderately slow Typical profile: Available water capacity: 2.0 to 3.5 inches 0 to 4 inches—dark brown gravelly loam Potential rooting depth: 10 to 20 inches 4 to 11 inches—dark brown gravelly loam Runoff: Slow 11 to 42 inches—dark brown gravelly clay Hazard of water erosion: Slight loam Contrasting Inclusions 42 to 62 inches—light yellowish brown gravelly clay loam Chiara soils on lower lying terraces, Chuska soils Depth class: Very deep on higher lying terraces, areas of Rock Drainage class: Well drained outcrop Permeability: Moderately slow Available water capacity: 8 to 9 inches Use and Management Potential rooting depth: 60 inches or more Major use: Rangeland Runoff: Medium Major management factors: Precipitation, depth Hazard of water erosion: Moderate to the hardpan, available water capacity, rock Shrink-swell potential: Moderate fragments in the surface layer Dominant vegetation in natural potential plant Contrasting Inclusions community: Thurber needlegrass, Wyoming big sagebrush Amboat and Brose soils on summits, Doodlelink General management considerations: and Eep soils on breaks, Isknat soils on fan • Forage production is limited by the low terraces, Oshone soils on lower lying 50 Soil Survey

terraces, areas of Rock outcrop, Hazard of water erosion: Moderate outcroppings of volcanic ash Shrink-swell potential: Moderate Use and Management Characteristics of the Rock Outcrop Major use: Rangeland Kind of rock: Exposed welded tuff Major management factor: Hazard of water Description of areas: Semirounded, weathered erosion cliffs and rimrock that border narrow, lower Dominant vegetation in natural potential plant lying valley terraces; large semirounded community: Idaho fescue, mountain big fragments randomly deposited downslope; sagebrush and climatically sculptured areas along foot General management consideration: slopes • Seeding is limited by the moderate hazard of Contrasting Inclusions water erosion. Eep and Kavon soils on breaks and hill slopes, Interpretive Groups Hogmalat soils on shoulders and summits, Land capability classification: IIIe, nonirrigated Keman soils on summits, Rutherford soils on Range site: Loamy, 13 to 16 inch precipitation ridges and dip slopes zone Use and Management Major use: Rangeland 32—Dehana-Rock outcrop complex, 4 Major management factors: Growing season, to 40 percent slopes slope, areas of Rock outcrop, hazard of water erosion Composition Dominant vegetation in natural potential plant community: Dehana soil—needlegrass, Dehana soil and similar inclusions—60 percent quaking aspen Rock outcrop—20 percent General management considerations: Contrasting inclusions—20 percent • Forage production is limited by the short Setting growing season. • Seeding is limited by slope, the areas of Rock Position on landscape: Breaks and hill slopes outcrop, and the moderate hazard of water Elevation: 5,800 to 7,600 feet erosion. Average annual precipitation: 20 to 25 inches • The use of equipment is limited by slope and Average annual air temperature: 40 to 42 the areas of Rock outcrop. degrees F • Because cold soil temperatures limit plant Frost-free season: 20 to 60 days growth, grazing should be delayed until the soil Characteristics of the Dehana Soil has warmed up and the forage plants have achieved sufficient growth. Typical profile: 0 to 6 inches—very dark grayish brown Interpretive Groups gravelly loam 6 to 15 inches—dark grayish brown gravelly Land capability classification: VIe, nonirrigated loam Range site: Dehana soil—Aspen woodland, 16+ 15 to 30 inches—brown gravelly loam inch precipitation zone 30 to 65 inches—brown gravelly clay loam 65 to 70 inches—yellowish brown silty clay loam 33—Dolman silt loam, 1 to 4 percent Depth class: Very deep slopes Drainage class: Well drained Permeability: Moderately slow Composition Available water capacity: 7.0 to 8.5 inches Potential rooting depth: 60 inches or more Dolman soil and similar inclusions—90 percent Runoff: Medium Contrasting inclusions—10 percent Jerome-Twin Falls, Idaho 51

Setting Interpretive Groups Position on landscape: Terraces Land capability classification: IIIs, irrigated, and Elevation: 3,000 to 4,000 feet VIs, nonirrigated Average annual precipitation: 8 to 10 inches Range site: Loamy, 8 to 10 inch precipitation Average annual air temperature: 47 to 49 zone degrees F Frost-free season: 120 to 140 days 34—Doodlelink very gravelly loam, 8 Characteristics of the Dolman Soil to 30 percent slopes Typical profile: 0 to 21 inches—pale brown silt loam Composition 21 to 27 inches—light gray loam Doodlelink soil and similar inclusions—85 27 to 45 inches—white lime- and silica- percent cemented hardpan Contrasting inclusions—15 percent 45 to 61 inches—sand and gravel Depth class: Moderately deep to a hardpan Setting Drainage class: Well drained Position on landscape: Breaks Permeability: Moderate Elevation: 4,800 to 6,400 feet Available water capacity: 4.0 to 6.5 inches Average annual precipitation: 14 to 18 inches Potential rooting depth: 20 to 40 inches Average annual air temperature: 42 to 45 Runoff: Slow degrees F Hazard of water erosion: Slight Frost-free season: 80 to 100 days Contrasting Inclusions Characteristics of the Doodlelink Soil Chiara soils on higher lying terraces; Paulville, Purdam, and Shano soils on lower lying Typical profile: terraces; Scoon soils adjacent to breaks 0 to 15 inches—dark grayish brown very gravelly loam Use and Management 15 to 26 inches—brown very gravelly loam Major uses: Irrigated cropland, rangeland 26 to 60 inches—pale brown very gravelly Major management factor: Precipitation sandy loam Depth class: Very deep Irrigated Cropland Drainage class: Well drained General management considerations: Permeability: Moderately slow • Most climatically suited crops can be grown if Available water capacity: 5 to 6 inches irrigation water is provided. Potential rooting depth: 60 inches or more • Surface and sprinkler irrigation systems are Runoff: Medium suited to this soil. Hazard of water erosion: Moderate Rangeland Contrasting Inclusions Dominant vegetation in natural potential plant community: Thurber needlegrass, Wyoming Congle soils on foot slopes; Gosinta and Tucker big sagebrush soils on alluvial terraces; Stricker soils on General management considerations: south- and west-facing breaks; soils that are • Forage production and seeding are limited by very deep, are very gravelly loam over very low precipitation. gravelly clay, and are in slump areas; soils • Seeding generally is most successful late in that are moderately deep to bedrock, are fall; however, it may not be successful in years very gravelly loam, and are on breaks; areas when precipitation is below average during the of Rock outcrop; outcroppings of volcanic growing season. ash 52 Soil Survey

Use and Management Contrasting Inclusions Major use: Rangeland Congle soils on foot slopes; Gosinta and Tucker Major management factors: Hazard of water soils on alluvial terraces; Nawt and Stricker erosion soils on west- and south-facing breaks; soils Dominant vegetation in natural potential plant that are very deep, are very gravelly loam community: Idaho fescue, mountain big over very gravelly clay, and are in slump sagebrush areas; soils that are moderately deep to General management consideration: bedrock, are very gravelly loam, and are on • Seeding is limited by the moderate hazard of breaks; areas of Rock outcrop; outcroppings water erosion. of volcanic ash Interpretive Groups Use and Management Land capability classification: VIIs, nonirrigated Major use: Rangeland Range site: Stony loam, 12 to 16 inch Major management factors: Slope, hazard of precipitation zone water erosion Dominant vegetation in natural potential plant community: Idaho fescue, mountain big 35—Doodlelink very gravelly loam, 30 sagebrush to 75 percent slopes General management considerations: • The use of forage by livestock is limited by Composition slope. • Seeding is limited by slope and the severe Doodlelink soil and similar inclusions—85 hazard of water erosion. percent • The use of equipment is limited by slope. Contrasting inclusions—15 percent Interpretive Groups Setting Land capability classification: VIIe, nonirrigated Position on landscape: Breaks Range site: North slope stony, 12 to 16 inch Elevation: 4,800 to 6,400 feet precipitation zone Average annual precipitation: 14 to 18 inches Average annual air temperature: 42 to 45 degrees F 36—Eep very cobbly sandy loam, 6 to Frost-free season: 80 to 100 days 35 percent slopes Composition Characteristics of the Doodlelink Soil Eep soil and similar inclusions—80 percent Typical profile: Contrasting inclusions—20 percent 0 to 6 inches—dark grayish brown very Setting gravelly loam 6 to 21 inches—dark brown and brown very Position on landscape: Breaks and hill slopes gravelly loam Elevation: 5,800 to 6,500 feet 21 to 65 inches—yellowish brown and brown Average annual precipitation: 16 to 20 inches extremely gravelly clay loam Average annual air temperature: 40 to 44 Depth class: Very deep degrees F Drainage class: Well drained Frost-free season: 60 to 100 days Permeability: Moderately slow Characteristics of the Eep Soil Available water capacity: 5 to 6 inches Potential rooting depth: 60 inches or more Typical profile: Runoff: Rapid 0 to 9 inches—dark grayish brown very Hazard of water erosion: Severe cobbly sandy loam Jerome-Twin Falls, Idaho 53

9 to 17 inches—brown very gravelly clay Rock outcrop—20 percent loam Contrasting inclusions—20 percent 17 to 26 inches—brown very gravelly loam Setting 26 to 38 inches—pale brown very cobbly sandy loam Position on landscape: Eep soil—west and south 38 to 76 inches—white unconsolidated aspects of breaks and hill slopes, Dehana loamy sand volcanic ash soil—north and east aspects of breaks and 76 to 78 inches—very pale brown hill slopes consolidated volcanic ash Elevation: 6,200 to 7,000 feet Depth class: Very deep Average annual precipitation: 18 to 25 inches Drainage class: Well drained Average annual air temperature: 40 to 44 Permeability: Moderate degrees F Available water capacity: 6 to 8 inches Frost-free season: 30 to 80 days Potential rooting depth: 60 inches or more Characteristics of the Eep Soil Runoff: Medium Hazard of water erosion: Moderate Typical profile: Hazard of wind erosion: Moderate 0 to 5 inches—dark grayish brown very cobbly sandy loam Contrasting Inclusions 5 to 26 inches—grayish brown and dark Congle soils on foot slopes, Dehana soils on grayish brown very cobbly loam breaks and hill slopes, Mug soils on higher 26 to 38 inches—brown very cobbly sandy lying terraces, very deep sandy loam on loam breaks and hill slopes, areas of Rock outcrop 38 to 65 inches—light gray unconsolidated loamy sand volcanic ash Use and Management Depth class: Very deep Major use: Rangeland Drainage class: Well drained Major management factors: Rock fragments in Permeability: Moderate the surface layer, hazard of water erosion, Available water capacity: 6 to 8 inches hazard of wind erosion Potential rooting depth: 60 inches or more Dominant vegetation in natural potential plant Runoff: Medium community: Idaho fescue, mountain big Hazard of water erosion: Moderate sagebrush, antelope bitterbrush Hazard of wind erosion: Moderate General management considerations: Characteristics of the Dehana Soil • Seeding is limited by the rock fragments in the surface layer and the moderate hazards of water Typical profile: and wind erosion. 0 to 6 inches—very dark grayish brown • The use of equipment is limited by the rock gravelly loam fragments in the surface layer. 6 to 17 inches—dark grayish brown gravelly loam Interpretive Groups 17 to 32 inches—brown gravelly loam Land capability classification: VIs, nonirrigated 32 to 60 inches—pale brown cobbly loam Range site: Loamy slope, 12 to 16 inch Depth class: Very deep precipitation zone Drainage class: Well drained Permeability: Moderately slow Available water capacity: 7.0 to 8.5 inches 37—Eep-Dehana-Rock outcrop Potential rooting depth: 60 inches or more association, 6 to 40 percent Runoff: Medium slopes Hazard of water erosion: Moderate

Composition Characteristics of the Rock Outcrop Eep soil and similar inclusions—35 percent Kind of rock: Exposed welded tuff Dehana soil and similar inclusions—25 percent Description of areas: Semirounded, weathered 54 Soil Survey

cliffs and rimrock that border narrow, lower Rock outcrop—15 percent lying valley terraces; large semirounded Contrasting inclusions—20 percent fragments randomly deposited downslope; Setting and climatically sculptured areas along foot slopes Position on landscape: Breaks Elevation: 6,200 to 7,000 feet Contrasting Inclusions Average annual precipitation: 18 to 25 inches Kavon soils on hill slopes, Keman and Hogmalat Average annual air temperature: 40 to 44 soils on summits, Rutherford soils on ridges degrees F and dip slopes Frost-free season: 30 to 80 days Use and Management Characteristics of the Eep Soil Major use: Rangeland Typical profile: Major management factors: Dehana soil— 0 to 10 inches—dark grayish brown very growing season, slope, hazard of water cobbly sandy loam erosion, areas of Rock outcrop; Eep soil— 10 to 23 inches—dark grayish brown very rock fragments in the surface layer, slope, gravelly clay loam hazards of wind and water erosion; areas of 23 to 29 inches—yellowish brown very Rock outcrop gravelly sandy loam Dominant vegetation in natural potential plant 29 to 34 inches—yellowish brown extremely community: Eep soil—Idaho fescue, gravelly sandy loam mountain big sagebrush, antelope 34 to 60 inches—unconsolidated loamy sand bitterbrush; Dehana soil—needlegrass, volcanic ash quaking aspen Depth class: Very deep General management considerations: Drainage class: Well drained • Forage production is limited by the short Permeability: Moderate growing season of the Dehana soil. Available water capacity: 6 to 8 inches • Because cold soil temperatures limit plant Potential rooting depth: 60 inches or more growth, grazing should be delayed until the Runoff: Rapid Dehana soil has warmed and the forage plants Hazard of water erosion: Severe have achieved sufficient growth. Hazard of wind erosion: Moderate • Seeding is limited by the rock fragments in the Characteristics of the Dehana Soil surface layer of the Eep soil, the moderate hazard of wind erosion on the Eep soil, slope, Typical profile: areas of Rock outcrop, and moderate hazard of 0 to 4 inches—very dark grayish brown water erosion. gravelly loam • The use of equipment is limited by slope and 4 to 25 inches—very dark grayish brown the areas of Rock outcrop. cobbly loam 25 to 40 inches—brown cobbly loam Interpretive Groups 40 to 50 inches—brown gravelly clay loam Land capability classification: VIs, nonirrigated 50 to 60 inches—pale brown gravelly loam Range site: Eep soil—Loamy slope, 12 to 16 inch Depth class: Very deep precipitation zone; Dehana soil—Aspen Drainage class: Well drained woodland, 16+ inch precipitation zone Permeability: Moderately slow Available water capacity: 7.0 to 8.5 inches 38—Eep-Dehana-Rock outcrop Potential rooting depth: 60 inches or more association, 40 to 75 percent Runoff: Rapid slopes Hazard of water erosion: Severe Composition Characteristics of the Rock Outcrop Eep soil and similar inclusions—40 percent Kind of rock: Exposed welded tuff Dehana soil and similar inclusions—25 percent Description of areas: Semirounded, weathered Jerome-Twin Falls, Idaho 55

cliffs and rimrock that border narrow, lower Setting lying valley terraces; large semirounded Position on landscape: Terraces fragments randomly deposited downslope; Elevation: 5,200 to 5,800 feet and climatically sculptured areas along foot Average annual precipitation: 9 to 11 inches slopes Average annual air temperature: 43 to 45 Contrasting Inclusions degrees F Frost-free season: 85 to 95 days Kavon soils on hill slopes, Keman soils on summits, Hogmalat soils on summits and Characteristics of the Elhina Soil shoulders, Rutherford soils on ridges and dip Typical profile: slopes 0 to 1 inch—grayish brown very gravelly Use and Management loam 1 inch to 3 inches—light brownish gray Major use: Rangeland gravelly clay loam Major management factors: Dehana soil— 3 to 8 inches—brown clay growing season; slope, hazard of water 8 to 12 inches—light yellowish brown clay erosion, areas of Rock outcrop; Eep soil— 12 to 21 inches—pale brown extremely rock fragments in the surface layer, hazards gravelly loam of wind and water erosion, slope, areas of 21 to 32 inches—white fractured lime- and Rock outcrop silica-cemented hardpan Dominant vegetation in natural potential plant 32 to 60 inches—brownish yellow weakly community: Eep soil—Idaho fescue, cemented extremely gravelly sand mountain big sagebrush, antelope Depth class: Moderately deep to a hardpan bitterbrush; Dehana soil—needlegrass, Drainage class: Well drained quaking aspen Permeability: Slow General management considerations: Available water capacity: 2.0 to 3.5 inches • Forage production is limited by the short Potential rooting depth: 20 to 40 inches growing season of the Dehana soil. Runoff: Slow • The use of forage by livestock is limited by Hazard of water erosion: Slight slope, rock fragments in the surface layer of the Shrink-swell potential: High Eep soil, and areas of Rock outcrop. • Seeding is limited by the areas of Rock Contrasting Inclusions outcrop, rock fragments in the surface layer of Ackett soils on stream terraces; Aninto soils on the Eep soil, slope, the moderate hazard of wind the sides of terraces; Howcree and Oshone erosion on the Eep soil, and the severe hazard of soils on higher lying terraces and fans; Isknat water erosion on the Dehana and Eep soils. soils on fan terraces; Tucker soils on lower • The use of equipment is limited by the areas of lying terraces; very deep, poorly drained Rock outcrop and slope. soils that are silt loam over silty clay and are Interpretive Groups in depressional areas of alluvial fans and in drainageways Land capability classification: VIIe, nonirrigated Range site: Eep soil—Loamy slope, 12 to 16 inch Use and Management precipitation zone; Dehana soil—Aspen Major use: Rangeland woodland, 16+ inch precipitation zone Major management factors: Precipitation, rock fragments in the surface layer, depth to the 39—Elhina very gravelly loam, 2 to 6 clayey subsoil percent slopes Dominant vegetation in natural potential plant community: Bluebunch wheatgrass, black sagebrush Composition General management considerations: Elhina soil and similar inclusions—80 percent • Forage production is limited by the low Contrasting inclusions—20 percent precipitation and shallow rooting depth. 56 Soil Survey

• Plant rooting depth is limited to the upper part Contrasting Inclusions of the soil because of the claypan. Owsel, Minidoka, and Sluka soils on terraces • Seeding is limited by the low precipitation and rock fragments in the surface layer. Use and Management • Seeding generally is most successful late in Major uses: Rangeland, irrigated cropland fall; however, it may not be successful in years Major management factors: Precipitation, when precipitation is below average during the permeability, hazard of water erosion growing season. Rangeland Interpretive Groups Dominant vegetation in natural potential plant Land capability classification: VIs, nonirrigated community: Bluebunch wheatgrass, Range site: Shallow calcareous loam, 10 to 16 Wyoming big sagebrush inch precipitation zone General management considerations: • Forage production is limited by low 40—Elijah silt loam, 2 to 4 percent precipitation. slopes • Seeding is limited by low precipitation and the moderate hazard of water erosion. • Seeding generally is most successful late in Composition fall; however, it may not be successful in years Elijah soil and similar inclusions—95 percent when precipitation is below average during the Contrasting inclusions—5 percent growing season. Irrigated Cropland Setting General management considerations: Position on landscape: Terraces • Most climatically suited crops can be grown if Elevation: 4,600 to 5,200 feet irrigation water is provided. Average annual precipitation: 8 to 10 inches • Sprinkler irrigation is best suited to this soil, but Average annual air temperature: 46 to 48 surface irrigation can be used if the water is degrees F regulated to control erosion. Frost-free season: 110 to 120 days • Because of the moderately slow permeability, the application of irrigation water should be Characteristics of the Elijah Soil adjusted to the water intake rate. • Production of irrigated crops is limited by the Typical profile: moderate hazard of water erosion. 0 to 3 inches—pale brown silt loam • Regulating irrigation water helps to control 3 to 10 inches—pale brown silty clay loam runoff and erosion. 10 to 23 inches—very pale brown silt loam 23 to 27 inches—white lime- and silica- Interpretive Groups cemented hardpan Land capability classification: IIIs, irrigated, and 27 to 32 inches—light yellowish brown sandy VIs, nonirrigated loam Range site: Loamy, 8 to 12 inch precipitation 32 to 60 inches—white lime- and silica- zone cemented hardpan Depth class: Moderately deep to a hardpan Drainage class: Well drained 41—Elijah-Pigtail complex, 1 to 6 Permeability: Moderately slow percent slopes Available water capacity: 5 to 8 inches Composition Potential rooting depth: 20 to 40 inches Runoff: Medium Elijah soil and similar inclusions—60 percent Hazard of water erosion: Moderate Pigtail soil and similar inclusions—25 percent Shrink-swell potential: Moderate Contrasting inclusions—15 percent Jerome-Twin Falls, Idaho 57

Setting Use and Management Position on landscape: Elijah soil—convex areas Major use: Rangeland of terraces, Pigtail soils—concave areas of Major management factors: Elijah soil—hazard of terraces water erosion, precipitation; Pigtail soil— Elevation: 4,600 to 5,200 feet depth to the clayey subsoil, precipitation Average annual precipitation: 9 to 12 inches Dominant vegetation in natural potential plant Average annual air temperature: 46 to 48 community: Elijah soil—bluebunch degrees F wheatgrass, Wyoming big sagebrush; Pigtail Frost-free season: 100 to 110 days soil—Thurber needlegrass, Wyoming big sagebrush Characteristics of the Elijah Soil General management considerations: Slope range: 1 to 6 percent • Forage production is limited by low Typical profile: precipitation and the shallow rooting depth of the 0 to 3 inches—pale brown silt loam Pigtail soil. 3 to 14 inches—pale brown silty clay loam • Plant rooting depth is limited to the upper part 14 to 38 inches—very pale brown loam of the Pigtail soil because of the claypan. 38 to 60 inches—white fractured lime- and • Seeding is limited by low precipitation and the silica-cemented hardpan moderate hazard of water erosion on the Elijah Depth class: Moderately deep to a hardpan soil. Drainage class: Well drained • Seeding generally is most successful late in Permeability: Moderately slow fall; however, it may not be successful in years Available water capacity: 5 to 8 inches when precipitation is below average during the Potential rooting depth: 20 to 40 inches growing season. Runoff: Medium Interpretive Groups Hazard of water erosion: Moderate Shrink-swell potential: Moderate Land capability classification: VIs, nonirrigated Range site: Elijah soil—Loamy, 8 to 12 inch Characteristics of the Pigtail Soil precipitation zone; Pigtail soil—Slick spot Slope range: 1 to 3 percent sodic, 8 to 14 inch precipitation zone Typical profile: 0 to 3 inches—pale brown silt loam 3 to 7 inches—pale brown silty clay loam 42—Fathom loamy fine sand, 0 to 12 7 to 15 inches—pale brown silty clay percent slopes 15 to 31 inches—very pale brown silt loam 31 to 60 inches—white fractured lime- and Composition silica-cemented hardpan Fathom soil and similar inclusions—90 percent Depth class: Moderately deep to a hardpan Contrasting inclusions—10 percent Drainage class: Well drained Permeability: Very slow Setting Available water capacity: 5.5 to 7.0 inches Position on landscape: Alluvial fans and terraces Potential rooting depth: 20 to 40 inches Elevation: 3,000 to 3,700 feet Runoff: Slow Average annual precipitation: 8 to 10 inches Hazard of water erosion: Slight Average annual air temperature: 49 to 51 Shrink-swell potential: High degrees F Contrasting Inclusions Frost-free season: 130 to 140 days Owsel, Power, Roseworth, and Tanner soils in Characteristics of the Fathom Soil concave areas of terraces; soils that are moderately deep to a hardpan, are silt loam Typical profile: over silty clay, and are in depressional areas 0 to 9 inches—brown loamy fine sand of terraces 9 to 60 inches—pale brown loamy fine sand 58 Soil Survey

Depth class: Very deep Average annual air temperature: 49 to 51 Drainage class: Somewhat excessively drained degrees F Permeability: Rapid Frost-free season: 130 to 140 days Available water capacity: 5.5 to 6.0 inches Characteristics of the Fathom Soil Potential rooting depth: 60 inches or more Runoff: Slow Typical profile: Hazard of water erosion: Slight 0 to 14 inches—brown loamy fine sand Hazard of wind erosion: Severe 14 to 24 inches—pale brown loamy fine sand 24 to 60 inches—light gray loamy fine sand Contrasting Inclusions Depth class: Very deep Banbury and Kecko soils on higher lying Drainage class: Somewhat excessively drained terraces; very deep, poorly drained soils that Permeability: Rapid are loamy fine sand and are in depressional Available water capacity: 5.5 to 6.0 inches areas of foot slopes; undulating sand dunes Potential rooting depth: 60 inches or more along the Snake River Runoff: Rapid Hazard of water erosion: Severe Use and Management Hazard of wind erosion: Severe Major use: Rangeland Contrasting Inclusions Major management factors: Precipitation, hazard of wind erosion Kudlac soils on breaks, very deep soils that are Dominant vegetation in natural potential plant loamy sand over clay and are on breaks community: Indian ricegrass, Use and Management needleandthread, basin big sagebrush General management considerations: Major use: Rangeland • Forage production is limited by low Major management factors: Precipitation, slope, precipitation. hazard of water erosion, hazard of wind • Seeding is limited by low precipitation and the erosion severe hazard of wind erosion. Dominant vegetation in natural potential plant • Seeding generally is most successful late in community: Indian ricegrass, fall; however, it may not be successful in years needleandthread, basin big sagebrush when precipitation is below average during the General management considerations: growing season. • Forage production is limited by low • Seeding burned or disturbed areas helps to precipitation. control blowing and drifting sand. • The use of forage by livestock is limited by slope. Interpretive Groups • Seeding is limited by low precipitation, slope, and the severe hazards of water and wind Land capability classification: VIe, nonirrigated erosion. Range site: Sand, 8 to 12 inch precipitation zone • The use of equipment is limited by slope.

Interpretive Groups 43—Fathom loamy fine sand, 30 to 60 percent slopes Land capability classification: VIIe, nonirrigated Range site: Sand, 8 to 12 inch precipitation zone Composition Fathom soil and similar inclusions—90 percent 44—Fathom bouldery loamy fine Contrasting inclusions—10 percent sand, 2 to 20 percent slopes Setting Composition Position on landscape: Breaks Elevation: 3,000 to 3,700 feet Fathom soil and similar inclusions—90 percent Average annual precipitation: 8 to 10 inches Contrasting inclusions—10 percent Jerome-Twin Falls, Idaho 59

Setting 45—Forvic silty clay loam, 2 to 6 Position on landscape: Alluvial fans and terraces percent slopes Elevation: 3,000 to 3,700 feet Average annual precipitation: 8 to 10 inches Composition Average annual air temperature: 49 to 51 Forvic soil and similar inclusions—85 percent degrees F Contrasting inclusions—15 percent Frost-free season: 130 to 140 days Setting Characteristics of the Fathom Soil Position on landscape: Terraces Typical profile: Elevation: 5,800 to 6,200 feet 0 to 12 inches—brown bouldery loamy fine Average annual precipitation: 16 to 18 inches sand Average annual air temperature: 41 to 43 12 to 60 inches—pale brown loamy fine sand degrees F Depth class: Very deep Frost-free season: 80 to 90 days Drainage class: Somewhat excessively drained Characteristics of the Forvic Soil Permeability: Rapid Available water capacity: 5.5 to 6.0 inches Typical profile: Potential rooting depth: 60 inches or more 0 to 7 inches—dark grayish brown silty clay Runoff: Slow loam Hazard of water erosion: Slight 7 to 12 inches—brown clay Hazard of wind erosion: Severe 12 to 21 inches—dark brown gravelly clay 21 to 30 inches—light brown very gravelly Contrasting Inclusions sandy clay 30 to 35 inches—white lime- and silica- Banbury and Kecko soils on higher lying cemented hardpan terraces; very deep, poorly drained loamy 35 inches—very pale brown welded volcanic sand, in depressional areas of alluvial fans ash and terraces Depth class: Moderately deep to a hardpan Drainage class: Well drained Use and Management Permeability: Slow Major use: Rangeland Available water capacity: 4 to 6 inches Major management factors: Precipitation, rock Potential rooting depth: 20 to 40 inches fragments in the surface layer, hazard of Runoff: Medium wind erosion Hazard of water erosion: Moderate Dominant vegetation in natural potential plant Shrink-swell potential: High community: Indian ricegrass, Contrasting Inclusions needleandthread, basin big sagebrush General management considerations: Aninto soils on lower lying terraces; Brose soils • Forage production is limited by low on summits; Eep soils on hill slopes; precipitation. Howcree soils on higher lying terraces; • Seeding is limited by low precipitation, rock soils that are very deep, are very gravelly fragments in the surface layer, and the severe silty clay loam over very gravelly silty clay, hazard of wind erosion. and are on the sides of terraces; soils that • The use of equipment is limited by rock are deep to a hardpan, are silty clay loam fragments in the surface layer. over gravelly clay, and are on terraces Use and Management Interpretive Groups Major use: Rangeland Land capability classification: VIIs, nonirrigated Major management factor: Hazard of water Range site: Sand, 8 to 12 inch precipitation zone erosion 60 Soil Survey

Dominant vegetation in natural potential plant deep sandy loam on alluvial terraces; soils community: Idaho fescue, mountain big that are very deep, are clay loam over clay, sagebrush and are on alluvial terraces General management considerations: Use and Management • Seeding is limited by the moderate hazard of water erosion. Major uses: Irrigated cropland, rangeland Major management factors: Precipitation, Interpretive Groups permeability Land capability classification: IVe, nonirrigated Irrigated Cropland Range site: Loamy, 13 to 16 inch precipitation zone General management considerations: • Most climatically suited crops can be grown if irrigation water is provided. 46—Gosinta silt loam, 0 to 2 percent • Surface and sprinkler irrigation systems are slopes suited to this soil. • Because of the moderately slow permeability, Composition the application of irrigation water should be adjusted to the water intake rate. Gosinta soil and similar inclusions—90 percent Contrasting inclusions—10 percent Rangeland Setting Dominant vegetation in natural potential plant community: Basin wildrye, basin big Position on landscape: Alluvial terraces sagebrush Elevation: 3,000 to 5,000 feet General management considerations: Average annual precipitation: 10 to 12 inches • Forage production and seeding are limited by Average annual air temperature: 47 to 50 low precipitation. degrees F • Seeding generally is most successful late in Frost-free season: 110 to 140 days fall; however, it may not be successful in years Characteristics of the Gosinta Soil when precipitation is below average during the growing season. Typical profile: 0 to 2 inches—dark grayish brown silt loam Interpretive Groups 2 to 24 inches—grayish brown silt loam Land capability classification: IIc, irrigated, and 24 to 38 inches—light brownish gray loam VIc, nonirrigated 38 to 50 inches—pale brown sandy loam Range site: Loamy bottom, 8 to 14 inch 50 to 65 inches—grayish brown very gravelly precipitation zone sandy loam Depth class: Very deep Drainage class: Moderately well drained 47—Harsan fine sandy loam, 1 to 4 Permeability: Moderately slow percent slopes Available water capacity: 8.5 to 10.0 inches Potential rooting depth: 60 inches or more Composition Runoff: Slow Hazard of water erosion: Slight Harsan soil and similar inclusions—80 percent Depth to water table: 24 to 48 inches Contrasting inclusions—20 percent Frequency of flooding: Rare Setting Shrink-swell potential: Moderate Position on landscape: Terraces Contrasting Inclusions Elevation: 3,500 to 4,000 feet Antelope Springs, Bahem, and Paniogue soils on Average annual precipitation: 9 to 10 inches higher lying terraces; soils that are very deep Average annual air temperature: 48 to 50 and poorly drained, are loam over clay loam degrees F over loam, and are on alluvial terraces; very Frost-free season: 130 to 140 days Jerome-Twin Falls, Idaho 61

Characteristics of the Harsan Soil 48—Harsan-Sidlake-Quincy complex, Typical profile: 1 to 8 percent slopes 0 to 11 inches—pale brown fine sandy loam 11 to 23 inches—pale brown sandy loam Composition 23 to 29 inches—pale brown sandy clay Harsan soil and similar inclusions—35 percent loam Sidlake soil and similar inclusions—25 percent 29 to 37 inches—very pale brown sandy clay Quincy soil and similar inclusions—20 percent loam Contrasting inclusions—20 percent 37 to 52 inches—very pale brown silt loam 52 to 60 inches—very pale brown lime- and Setting silica-cemented hardpan Position on landscape: Harsan soil—plane areas Depth class: Deep to a hardpan of terraces, Sidlake and Quincy soils— Drainage class: Well drained concave areas of terraces Permeability: Moderately slow Elevation: 3,500 to 4,000 feet Available water capacity: 7 to 8 inches Average annual precipitation: 8 to 10 inches Potential rooting depth: 40 to 60 inches Average annual air temperature: 48 to 50 Runoff: Slow degrees F Hazard of water erosion: Slight Frost-free season: 130 to 140 days Hazard of wind erosion: Moderate Shrink-swell potential: Moderate Characteristics of the Harsan Soil Contrasting Inclusions Typical profile: 0 to 4 inches—brown loamy sand Arbidge, Emberton, Jestrick, Sidlake, and 4 to 9 inches—brown loamy fine sand Taunton soils on terraces; Shano soils on 9 to 19 inches—yellowish brown sandy loam higher lying terraces; soils that are shallow to 19 to 34 inches—light yellowish brown sandy bedrock, are loamy fine sand over fine sandy clay loam loam, and are on terraces; areas of Rock 34 to 54 inches—very pale brown clay loam outcrop 54 to 60 inches—very pale brown lime- and Use and Management silica-cemented hardpan Depth class: Deep to a hardpan Major use: Irrigated cropland Drainage class: Well drained Major management factors: Permeability, hazard Permeability: Moderately slow of wind erosion Available water capacity: 5.5 to 8.5 inches General management considerations: Potential rooting depth: 40 to 60 inches • Most climatically suited crops can be grown if Runoff: Slow irrigation water is provided. Hazard of water erosion: Slight • Surface and sprinkler irrigation systems are Hazard of wind erosion: Severe suited to this soil. Shrink-swell potential: Moderate • Because of the moderately slow permeability, the application of irrigation water should be Characteristics of the Sidlake Soil adjusted to the water intake rate. Typical profile: • Production of irrigated crops is limited by the 0 to 12 inches—brown and yellowish brown moderate hazard of wind erosion. loamy fine sand 12 to 32 inches—yellowish brown sandy clay Interpretive Groups loam Land capability classification: IIe, irrigated, and 32 inches—bedrock VIe, nonirrigated Depth class: Moderately deep to bedrock 62 Soil Survey

Drainage class: Well drained when precipitation is below average during the Permeability: Moderately slow growing season. Available water capacity: 3.5 to 6.0 inches • Seeding burned or disturbed areas helps to Potential rooting depth: 20 to 40 inches control blowing and drifting sand. Runoff: Slow Irrigated Cropland Hazard of water erosion: Slight Hazard of wind erosion: Severe General management considerations: Shrink-swell potential: Moderate • Most climatically suited crops can be grown if irrigation water is provided. Characteristics of the Quincy Soil • Sprinkler irrigation is suited to this unit. Typical profile: • Because the permeability of the Harsan and 0 to 6 inches—pale brown loamy sand Sidlake soils is moderately slow, the application 6 to 42 inches—pale brown loamy sand of irrigation water should be adjusted to the 42 to 48 inches—pale brown clay loam water intake rate. 48 to 52 inches—very pale brown clay loam • The production of irrigated crops is limited by 52 to 65 inches—white lime- and silica- slope and the severe hazard of wind erosion. cemented hardpan • The risk of wind erosion is reduced by Depth class: Deep to a hardpan maintaining crop residue on the surface, keeping Drainage class: Excessively drained tillage at a minimum, and keeping the surface of Permeability: Rapid in the upper 42 inches, the soil rough. moderately slow below Interpretive Groups Available water capacity: 6 to 7 inches Potential rooting depth: 40 to 60 inches Land capability classification: IIIe, irrigated, and Runoff: Slow VIe, nonirrigated Hazard of water erosion: Slight Range site: Sand, 8 to 12 inch precipitation zone Hazard of wind erosion: Severe Contrasting Inclusions 49—Hogmalat-Rock outcrop complex, Kecko and Emberton soils in plane areas of 3 to 40 percent slopes terraces; very deep soils that are sandy loam over sandy clay loam over clay loam and are Composition in concave areas of terraces; areas of Rock Hogmalat soil and similar inclusions—50 percent outcrop Rock outcrop—30 percent Use and Management Contrasting inclusions—20 percent Major uses: Rangeland, irrigated cropland Setting Major management factors: Harsan and Sidlake Position on landscape: Summits and shoulders soils—permeability; Harsan, Quincy, and Elevation: 6,800 to 7,600 feet Sidlake soils—slope, precipitation, hazard of Average annual precipitation: 20 to 25 inches wind erosion Average annual air temperature: 36 to 39 Rangeland degrees F Frost-free season: 20 to 50 days Dominant vegetation in natural potential plant community: Indian ricegrass, Characteristics of the Hogmalat Soil needleandthread, basin big sagebrush Typical profile: General management considerations: 0 to 3 inches—brown extremely gravelly • Forage production is limited by low loam precipitation. 3 to 15 inches—brown very gravelly clay • Seeding is limited by low precipitation and the loam severe hazard of wind erosion. 15 inches—bedrock • Seeding generally is most successful late in Depth class: Shallow to bedrock fall; however, it may not be successful in years Drainage class: Well drained Jerome-Twin Falls, Idaho 63

Permeability: Moderately slow 50—Hoosegow-Sidlake-Rock outcrop Available water capacity: 1.0 to 2.5 inches complex, 2 to 15 percent slopes Potential rooting depth: 9 to 20 inches Runoff: Medium Composition Hazard of water erosion: Moderate Shrink-swell potential: Moderate Hoosegow soil and similar inclusions—45 percent Characteristics of the Rock Outcrop Sidlake soil and similar inclusions—20 percent Kind of rock: Exposed welded tuff Rock outcrop—15 percent Description of areas: Climatically sculptured Contrasting inclusions—20 percent areas ranging from flat, irregularly shaped plates that are level with the surrounding Setting landscape to large outcroppings that are 10 to 20 feet high and as much as 30 feet in Position on landscape: Hoosegow soil—concave diameter areas of terraces, Sidlake soil—convex areas of terraces Contrasting Inclusions Elevation: 3,500 to 4,000 feet Kavon soils on hill slopes; Keman soils on Average annual precipitation: 9 to 11 inches summits; Rutherford soils on ridges; barren Average annual air temperature: 47 to 49 areas that are 10 to 20 feet in diameter and degrees F are saline, are shallow and clayey, or are Frost-free season: 130 to 140 days subject to ant activity Characteristics of the Hoosegow Soil Use and Management Major use: Rangeland Typical profile: Major management factors: Growing season, 0 to 6 inches—brown loam depth to bedrock, available water capacity, 6 to 35 inches—yellowish brown loam rock fragments in the surface layer, slope, 35 to 62 inches—light yellowish brown loam hazard of water erosion, areas of Rock 62 to 72 inches—yellowish brown loam outcrop Depth class: Very deep Dominant vegetation in natural potential plant Drainage class: Well drained community: Hogmalat soil—bluegrass, Permeability: Moderate curlleaf mountainmahogany Available water capacity: 9.5 to 11.5 inches General management considerations: Potential rooting depth: 60 inches or more • Forage production is limited by the short Runoff: Medium growing season, shallow rooting depth, and low Hazard of water erosion: Moderate available water capacity. Shrink-swell potential: Moderate • Because cold soil temperatures limit plant growth, grazing should be delayed until the soil Characteristics of the Sidlake Soil has warmed up and the forage plants have achieved sufficient growth. Typical profile: • Seeding is limited by rock fragments in the 0 to 12 inches—yellowish brown loam surface layer, areas of Rock outcrop, slope, and 12 to 32 inches—light yellowish brown loam the moderate hazard of water erosion. 32 inches—fractured bedrock • The use of equipment is limited by the areas of Depth class: Moderately deep to bedrock Rock outcrop, rock fragments in the surface Drainage class: Well drained layer, and slope. Permeability: Moderately slow Available water capacity: 3.5 to 6.0 inches Interpretive Groups Potential rooting depth: 20 to 40 inches Land capability classification: VIe, nonirrigated Runoff: Medium Range site: Mahogany savannah, 16 to 22 inch Hazard of water erosion: Moderate precipitation zone Shrink-swell potential: Moderate 64 Soil Survey

Characteristics of the Rock Outcrop Setting Kind of rock: Exposed basalt Position on landscape: Howcree soil—plane and Description of areas: Sharp, angular to concave areas of terraces; Ibola soil— semirounded, long, narrow ridges ranging to convex areas of terraces semirounded areas that extend 1 foot to 10 Elevation: 5,500 to 6,000 feet feet above the adjacent landscape Average annual precipitation: 12 to 15 inches Average annual air temperature: 41 to 45 Contrasting Inclusions degrees F Banbury, Barrymore, Emberton, and Power soils Frost-free season: 90 to 100 days on higher lying terraces; Harsan, Kecko and Characteristics of the Howcree Soil McCain soils in concave areas of terraces; Owinza soils in depressional areas of Typical profile: terraces 0 to 4 inches—dark grayish brown loam 4 to 11 inches—grayish brown gravelly clay Use and Management loam 11 to 19 inches—brown gravelly clay Major uses: Rangeland 19 to 30 inches—pale brown very gravelly Major management factors: Sidlake soil— clay permeability; Hoosegow and Sidlake soils— 30 to 60 inches—light yellowish brown slope, hazard of water erosion, precipitation, extremely gravelly sandy loam areas of Rock outcrop Depth class: Very deep Dominant vegetation in natural potential plant Drainage class: Well drained community: Hoosegow soil—basin wildrye, Permeability: Slow basin big sagebrush; Sidlake soil— Available water capacity: 4.5 to 6.5 inches bluebunch wheatgrass, Wyoming big Potential rooting depth: 60 inches or more sagebrush Runoff: Slow General management considerations: Hazard of water erosion: Slight • Forage production is limited by low Shrink-swell potential: High precipitation. • Seeding is limited by the low precipitation, Characteristics of the Ibola Soil areas of Rock outcrop, and moderate hazard of Typical profile: water erosion. 0 to 4 inches—brown loam • Seeding generally is most successful late in 4 to 8 inches—dark grayish brown loam fall; however, it may not be successful in years 8 to 18 inches—grayish brown clay loam when precipitation is below average during the 18 to 27 inches—light brown gravelly loam growing season. 27 to 28 inches—white silica-cemented hardpan Interpretive Groups 28 to 64 inches—light brown semiconsolidated volcanic ash Land capability classification: IIIe, irrigated, and Depth class: Moderately deep to a hardpan VIe, nonirrigated Drainage class: Well drained Range site: Hoosegow soil—Loamy bottom, 8 to Permeability: Moderately slow 14 inch precipitation zone; Sidlake soil— Available water capacity: 3.5 to 7.0 inches Loamy, 8 to 12 inch precipitation zone Potential rooting depth: 20 to 40 inches Runoff: Slow 51—Howcree-Ibola complex, 2 to 6 Hazard of water erosion: Slight percent slopes Shrink-swell potential: Moderate Contrasting Inclusions Composition Bancy and Budlewis soils on higher lying Howcree soil and similar inclusions—45 percent terraces; Eep soils on hill slopes; soils that Ibola soil and similar inclusions—40 are shallow to a hardpan, are loam over clay Contrasting inclusions—15 percent loam, and are in convex areas of terraces Jerome-Twin Falls, Idaho 65

Use and Management Use and Management

Major use: Rangeland Major uses: Rangeland Major management factors: None Major management factors: Wetness, flooding Dominant vegetation in natural potential plant Dominant vegetation in natural potential plant community: Idaho fescue, mountain big community: Sedge, slender wheatgrass sagebrush General management considerations: • Plants that tolerate wetness are suitable for Interpretive Groups seeding. • Grazing should be delayed until the soil is Land capability classification: IVs, nonirrigated adequately drained and is firm enough to Range site: Loamy, 13 to 16 inch precipitation withstand tramping by livestock. zone Interpretive Groups

52—Hutton mucky peat, 0 to 2 Land capability classification: IVw, nonirrigated percent slopes Range site: Semi-wet meadow Composition Hutton soil and similar inclusions—90 percent 53—Isknat loam, 2 to 8 percent Contrasting inclusions—10 percent slopes

Setting Composition Position on landscape: Flood plains Isknat soil and similar inclusions—80 percent Elevation: 5,500 to 5,800 feet Contrasting inclusions—20 percent Average annual precipitation: 12 to 16 inches Average annual air temperature: 44 to 46 Setting degrees F Frost-free season: 50 to 90 days Position on landscape: Alluvial fans Elevation: 5,800 to 5,900 feet Characteristics of the Hutton Soil Average annual precipitation: 15 to 16 Typical profile: inches 0 to 2 inches—mucky peat organic mat Average annual air temperature: 42 to 44 2 to 14 inches—very dark gray silty clay degrees F loam Frost-free season: 80 to 90 days 14 to 41 inches—gray silty clay loam 41 to 50 inches—gray clay Characteristics of the Isknat Soil 50 to 62 inches—light gray clay loam Depth class: Very deep Typical profile: Drainage class: Poorly drained 0 to 4 inches—dark grayish brown loam Permeability: Very slow 4 to 16 inches—dark grayish brown gravelly Available water capacity: 9 to 11 inches loam Potential rooting depth: 24 to 36 inches 16 to 25 inches—brown very gravelly Runoff: Slow clay Hazard of water erosion: Slight 25 to 43 inches—brown extremely gravelly Depth to water table: 12 to 24 inches clay Frequency of flooding: Occasional 43 to 60 inches—strong brown clay Shrink-swell potential: High Depth class: Very deep Drainage class: Well drained Contrasting Inclusions Permeability: Very slow Eep soils on hill slopes, Tucker soils on higher Available water capacity: 6 to 8 inches lying terraces Potential rooting depth: 60 inches or more 66 Soil Survey

Runoff: Medium 14 to 23 inches—dark grayish brown very Hazard of water erosion: Moderate gravelly clay Shrink-swell potential: High 23 to 38 inches—pale brown extremely gravelly clay Contrasting Inclusions 38 to 60 inches—pale brown extremely Amboat and Brose soils on summits; Dehana gravelly sandy loam and Eep soils on hill slopes; Howcree soils Depth class: Very deep on higher lying terraces; Oshone and Tucker Drainage class: Well drained soils on lower lying terraces; very deep soils Permeability: Slow that are sandy loam over sandy clay loam Available water capacity: 4 to 6 inches over sandy loam and are on hill slopes; very Potential rooting depth: 60 inches or more deep, poorly drained soils that are silt loam Runoff: Medium over silty clay and are in depressional areas Hazard of water erosion: Moderate of lower lying terraces Shrink-swell potential: High Use and Management Contrasting Inclusions Major use: Rangeland Oshone soils on higher lying terraces; Tucker Major management factor: Hazard of water soils on lower lying terraces; very deep soils erosion that are loam over clay loam over clay and Dominant vegetation in natural potential plant are on fan terraces; very deep, poorly community: Idaho fescue, mountain big drained soils that are silt loam over silty clay sagebrush and are in depressional areas of alluvial General management consideration: terraces • Seeding is limited by the moderate hazard of Use and Management water erosion. Major use: Rangeland Interpretive Groups Major management factor: Hazard of water Land capability classification: IVc, nonirrigated erosion Range site: Loamy, 13 to 16 inch precipitation Dominant vegetation in natural potential plant zone community: Idaho fescue, mountain big sagebrush General management consideration: 54—Isknat gravelly loam, 3 to 15 • Seeding is limited by the moderate hazard of percent slopes water erosion. Interpretive Groups Composition Land capability classification: IVc, nonirrigated Isknat soil and similar inclusions—80 percent Range site: Loamy, 13 to 16 inch precipitation Contrasting inclusions—20 percent zone Setting 55—Iwica-Budlewis complex, 2 to 6 Position on landscape: Fan terraces percent slopes Elevation: 5,200 to 5,900 feet Average annual precipitation: 12 to 16 inches Composition Average annual air temperature: 42 to 44 degrees F Iwica soil and similar inclusions—65 percent Frost-free season: 80 to 90 days Budlewis soil and similar inclusions—25 percent Contrasting inclusions—10 percent Characteristics of the Isknat Soil Setting Typical profile: 0 to 8 inches—gray gravelly loam Position on landscape: Iwica soil—convex areas 8 to 14 inches—dark grayish brown very of terraces; Budlewis soil—plane to concave gravelly clay loam areas of terraces Jerome-Twin Falls, Idaho 67

Elevation: 5,500 to 6,000 feet Use and Management Average annual precipitation: 12 to 15 inches Major use: Rangeland Average annual air temperature: 42 to 44 Major management factors: Budlewis soil—depth degrees F to the clayey subsoil; Iwica soil—none Frost-free season: 90 to 100 days Dominant vegetation in natural potential plant Characteristics of the Iwica Soil community: Iwica soil—Idaho fescue, mountain big sagebrush; Budlewis soil— Typical profile: Idaho fescue, low sagebrush 0 to 5 inches—dark grayish brown silt loam General management considerations: 5 to 12 inches—grayish brown silty clay loam • Forage production is limited by the shallow 12 to 30 inches—brown and pale brown clay rooting depth in the Budlewis soil. 30 to 42 inches—very pale brown gravelly • Plant rooting depth is limited to the upper part loam of the Budlewis soil because of the claypan. 42 to 60 inches—white lime- and silica- cemented hardpan over cemented sand Interpretive Groups and gravel Land capability classification: IVs, nonirrigated Depth class: Deep to a hardpan Range site: Iwica soil—Loamy, 13 to 16 inch Drainage class: Well drained precipitation zone; Budlewis soil—Shallow Permeability: Slow claypan, 12 to 16 inch precipitation zone Available water capacity: 5 to 6 inches Potential rooting depth: 40 to 60 inches Runoff: Slow 56—Jestrick-Kecko complex, 1 to 8 Hazard of water erosion: Slight percent slopes Shrink-swell potential: High Characteristics of the Budlewis Soil Composition Typical profile: Jestrick soil and similar inclusions—45 percent 0 to 4 inches—grayish brown silt loam Kecko soil and similar inclusions—40 percent 4 to 19 inches—light brownish gray and Contrasting inclusions—15 percent grayish brown silty clay Setting 19 to 26 inches—pale brown silty clay loam 26 to 27 inches—white lime- and silica- Position on landscape: Terraces cemented hardpan Elevation: 3,500 to 4,000 feet 27 inches—bedrock Average annual precipitation: 8 to 10 inches Depth class: Moderately deep to a hardpan Average annual air temperature: 47 to 49 Drainage class: Well drained degrees F Permeability: Slow Frost-free season: 130 to 140 days Available water capacity: 5 to 7 inches Characteristics of the Jestrick Soil Potential rooting depth: 20 to 40 inches Runoff: Slow Typical profile: Hazard of water erosion: Slight 0 to 12 inches—brown loamy fine sand Shrink-swell potential: High 12 to 31 inches—yellowish brown fine sandy loam Contrasting Inclusions 31 to 35 inches—pale brown cobbly loam Chayson, Howcree, Mug, and Oshone soils on 35 to 39 inches—white lime- and silica- lower lying terraces; very deep soils that are cemented hardpan gravelly loam over gravelly clay and are on 39 inches—fractured bedrock terraces Depth class: Moderately deep to a hardpan 68 Soil Survey

Drainage class: Somewhat excessively drained 57—Kavon very gravelly loam, 5 to 35 Permeability: Moderately rapid percent slopes Available water capacity: 3 to 4 inches Potential rooting depth: 21 to 38 inches Composition Runoff: Slow Hazard of water erosion: Slight Kavon soil and similar inclusions—75 percent Hazard of wind erosion: Severe Contrasting inclusions—25 percent Characteristics of the Kecko Soil Setting Typical profile: Position on landscape: Hill slopes 0 to 6 inches—light brownish gray fine sandy Elevation: 6,800 to 7,700 feet loam Average annual precipitation: 20 to 25 inches 6 to 20 inches—pale brown fine sandy loam Average annual air temperature: 38 to 41 20 to 29 inches—light gray fine sandy loam degrees F 29 to 42 inches—light gray sandy loam Frost-free season: 20 to 50 days 42 to 70 inches—very pale brown loamy fine Characteristics of the Kavon Soil sand Depth class: Very deep Typical profile: Drainage class: Well drained 0 to 4 inches—brown very gravelly loam Permeability: Moderately rapid 4 to 12 inches—dark grayish brown very Available water capacity: 7 to 8 inches gravelly loam Potential rooting depth: 60 inches or more 12 to 39 inches—brown very gravelly loam Runoff: Slow 39 to 62 inches—light yellowish brown Hazard of water erosion: Slight extremely gravelly clay loam Hazard of wind erosion: Severe Depth class: Very deep Drainage class: Well drained Contrasting Inclusions Permeability: Moderately slow Available water capacity: 4 to 6 inches Barrymore, Emberton, Harsan, Quincy, Starbuck, Potential rooting depth: 60 inches or more and Taunton soils on terraces; areas of Rock Runoff: Rapid outcrop Hazard of water erosion: Very severe Shrink-swell potential: Moderate Use and Management Acidity throughout the profile: Very strongly acid or extremely acid Major use: Irrigated cropland Contrasting Inclusions Major management factor: Hazard of wind erosion Dehana soils on breaks and hill slopes, Keman General management considerations: soils on summits, very deep soils that are • Most climatically suited crops can be grown if gravelly loam over gravelly sandy loam and irrigation water is provided. are on hill slopes, areas of Rock outcrop • Sprinkler irrigation is best suited to this unit. Use and Management • Production of irrigated crops is limited by the severe hazard of wind erosion. Major use: Rangeland • The risk of wind erosion is reduced by Major management factors: Acidity, base maintaining crop residue on the surface, planting saturation, short growing season, hazard of field windbreaks, keeping tillage at a minimum, water erosion and keeping the surface of the soil rough. Dominant vegetation in natural potential plant community: Snowbrush ceanothus Interpretive Groups General management considerations: Land capability classification: IIIe, irrigated, and • Forage production is limited by the short VIe, nonirrigated growing season, acidity, and low base saturation. Jerome-Twin Falls, Idaho 69

• Seeding is limited by the severe hazard of Sidlake soils on terraces; Tulch soils on water erosion. stream terraces; soils that are moderately • Plants that can tolerate the acidity of the soil deep to sand and gravel, are sandy loam, should be seeded. and are on lower lying terraces; areas of • These soils are hydrophobic because of the Rock outcrop waxy resin excreted from the snowbrush Use and Management ceanothus. Major uses: Rangeland, irrigated cropland Interpretive Groups Major management factors: Precipitation, hazard Land capability classification: VIIs, nonirrigated of wind erosion Range site: Ceanothus thicket, 16 to 24 inch Rangeland precipitation zone Dominant vegetation in natural potential plant community: Thurber needlegrass, Wyoming 58—Kecko fine sandy loam, 1 to 4 big sagebrush percent slopes General management considerations: • Forage production is limited by low Composition precipitation. • Seeding is limited by low precipitation and the Kecko soil and similar inclusions—85 percent moderate hazard of wind erosion. Contrasting inclusions—15 percent • Seeding generally is most successful late in Setting fall; however, it may not be successful in years when precipitation is below average during the Position on landscape: Terraces growing season. Elevation: 2,900 to 4,400 feet • Seeding burned or disturbed areas helps to Average annual precipitation: 8 to 11 inches control blowing and drifting sand. Average annual air temperature: 48 to 51 degrees F Irrigated Cropland Frost-free season: 120 to 140 days General management considerations: Characteristics of the Kecko Soil • Most climatically suited crops can be grown if irrigation water is provided. Typical profile: • Surface and sprinkler irrigation systems are 0 to 6 inches—light brownish gray fine sandy suited to this soil. loam • The risk of wind erosion is reduced by 6 to 13 inches—pale brown fine sandy loam maintaining crop residue on the surface, keeping 13 to 23 inches—light brownish gray fine tillage at a minimum, and keeping the surface of sandy loam the soil rough. 23 to 33 inches—light gray fine sandy loam 33 to 54 inches—light gray loamy fine sand Interpretive Groups 54 to 67 inches—white sand Land capability classification: IIe, irrigated, and Depth class: Very deep VIc, nonirrigated Drainage class: Well drained Range site: Loamy, 8 to 10 inch precipitation Permeability: Moderately rapid zone Available water capacity: 6 to 7 inches Potential rooting depth: 60 inches or more Runoff: Slow 59—Kecko fine sandy loam, 4 to 8 Hazard of water erosion: Slight percent slopes Hazard of wind erosion: Moderate Contrasting Inclusions Composition Bahem, Rad, Shano, and Sluka soils on higher Kecko soil and similar inclusions—85 percent lying terraces; Harsan, Paulville, Ouincy, and Contrasting inclusions—15 percent 70 Soil Survey

Setting Irrigated Cropland Position on landscape: Terraces General management considerations: Elevation: 2,900 to 4,400 feet • Most climatically suited crops can be grown if Average annual precipitation: 8 to 11 inches irrigation water is provided. Average annual air temperature: 48 to 51 • Sprinkler irrigation is best suited to this soil, but degrees F surface irrigation can be used if the water is Frost-free season: 120 to 140 days regulated to control erosion. • Regulating irrigation water helps to control Characteristics of the Kecko Soil runoff and erosion. Typical profile: • The risk of wind erosion is reduced by 0 to 5 inches—light brownish gray fine sandy maintaining crop residue on the surface, keeping loam tillage at a minimum, and keeping the surface of 5 to 23 inches—light brownish gray fine the soil rough. sandy loam Interpretive Groups 23 to 35 inches—pale brown loamy fine sand 35 to 47 inches—very pale brown loamy fine Land capability classification: IIIe, irrigated, and sand VIe, nonirrigated 47 to 55 inches—very pale brown loamy Range site: Loamy, 8 to 10 inch precipitation sand zone 55 to 72 inches—black and white sand Depth class: Very deep Drainage class: Well drained 60—Kecko-Emberton complex, 1 to 6 Permeability: Moderately rapid percent slopes Available water capacity: 6 to 7 inches Potential rooting depth: 60 inches or more Composition Runoff: Medium Kecko soil and similar inclusions—55 percent Hazard of water erosion: Moderate Emberton soil and similar inclusions—30 percent Hazard of wind erosion: Moderate Contrasting inclusions—15 percent Contrasting Inclusions Setting Bahem, Shano, and Taunton soils on higher lying Position on landscape: Kecko soil—concave terraces; Quincy soils on terraces; areas of areas of terraces, Emberton soil—plane to Rock outcrop convex areas of terraces Use and Management Elevation: 3,500 to 4,000 feet Average annual precipitation: 9 to 10 inches Major uses: Rangeland, irrigated cropland Average annual air temperature: 50 to 52 Major management factors: Precipitation, hazard degrees F of water erosion, hazard of wind erosion Frost-free season: 130 to 140 days Rangeland Characteristics of the Kecko Soil Dominant vegetation in natural potential plant community: Thurber needlegrass, Wyoming Typical profile: big sagebrush 0 to 7 inches—brown loamy fine sand General management considerations: 7 to 25 inches—yellowish brown fine sandy • Forage production is limited by low loam precipitation. 25 to 38 inches—very pale brown fine sandy • Seeding is limited by the low precipitation and loam the moderate hazards of water and wind erosion. 38 to 48 inches—very pale brown sandy • Seeding generally is most successful late in loam fall; however, it may not be successful in years 48 to 74 inches—pale brown fine sand when precipitation is below average during the Depth class: Very deep growing season. Drainage class: Well drained Jerome-Twin Falls, Idaho 71

Permeability: Moderately rapid 61—Keman very gravelly loam, 2 to Available water capacity: 5 to 7 inches 35 percent slopes Potential rooting depth: 60 inches or more Runoff: Slow Composition Hazard of water erosion: Slight Hazard of wind erosion: Severe Keman soil and similar inclusions—80 percent Contrasting inclusions—20 percent Characteristics of the Emberton Soil Setting Typical profile: 0 to 32 inches—yellowish brown loamy fine Position on landscape: Summits sand Elevation: 6,800 to 7,700 feet 32 to 39 inches—pale brown fine sandy loam Average annual precipitation: 20 to 25 inches 39 inches—bedrock Average annual air temperature: 38 to 41 Depth class: Moderately deep to bedrock degrees F Drainage class: Somewhat excessively drained Frost-free season: 20 to 50 days Permeability: Moderately rapid Characteristics of the Keman Soil Available water capacity: 2 to 4 inches Potential rooting depth: 20 to 40 inches Typical profile: Runoff: Slow 0 to 5 inches—very dark gray very gravelly Hazard of water erosion: Slight loam Hazard of wind erosion: Severe 5 to 33 inches—very dark grayish brown and dark grayish brown very gravelly loam Contrasting Inclusions 33 to 60 inches—light brownish gray Bahem, Banbury, and Trevino soils on higher extremely gravelly clay loam lying terraces; Harsan, Suepert, Quincy, and Depth class: Very deep Taunton soils in plane to convex areas of Drainage class: Well drained terraces; soils that are shallow to bedrock, Permeability: Moderate are loamy fine sand, and are on terraces; Available water capacity: 4.5 to 6.5 inches areas of Rock outcrop Potential rooting depth: 60 inches or more Runoff: Medium Use and Management Hazard of water erosion: Moderate Major use: Rangeland Shrink-swell potential: Moderate Major management factors: Precipitation, hazard Contrasting Inclusions of wind erosion Dominant vegetation in natural potential plant Dehana soils on hill slopes and breaks; Kavon community: Indian ricegrass, soils on hill slopes; Rutherford soils on needleandthread, basin big sagebrush ridges; soils that are moderately deep to General management considerations: bedrock, are very gravelly loam over • Forage production is limited by low extremely gravelly clay loam, and are on precipitation. summits; soils that are very deep, are very • Seeding is limited by low precipitation and the gravelly loam over very gravelly clay, and are severe hazard of wind erosion. on summits • Seeding generally is most successful late in Use and Management fall; however, it may not be successful in years when precipitation is below average during the Major use: Rangeland growing season. Major management factors: Growing season, • Seeding burned or disturbed areas helps to hazard of water erosion control blowing and drifting sand. Dominant vegetation in natural potential plant community: Idaho fescue, mountain big Interpretive Groups sagebrush General management considerations: Land capability classification: VIe, nonirrigated • Forage production is limited by the short Range site: Sand, 8 to 12 inch precipitation zone growing season. 72 Soil Survey

• Because cold soil temperatures limit plant breaks; very deep, poorly drained soils that growth, grazing should be delayed until the soil are silty clay over silty clay loam and are in has warmed up and the forage plants have depressional areas of terraces achieved sufficient growth. Use and Management • Seeding is limited by the moderate hazard of water erosion. Major use: Rangeland Major management factors: Precipitation, hazard Interpretive Groups of water erosion, hazard of wind erosion Land capability classification: VIe, nonirrigated Dominant vegetation in natural potential plant Range site: Loamy, 16+ inch precipitation zone community: Thurber needlegrass, Wyoming big sagebrush General management considerations: 62—Kudlac silty clay, 4 to 30 percent • Forage production is limited by low slopes precipitation. • Seeding is limited by low precipitation, the Composition severe hazard of water erosion, and the moderate hazard of wind erosion. Kudlac soil and similar inclusions—85 percent Contrasting inclusions—15 percent Interpretive Groups Setting Land capability classification: VIIe, nonirrigated Range site: Loamy, 8 to 10 inch precipitation Position on landscape: Terraces and breaks zone Elevation: 2,800 to 3,500 feet Average annual precipitation: 8 to 10 inches Average annual air temperature: 49 to 51 63—Lankbush loamy sand, 2 to 10 degrees F percent slopes Frost-free season: 130 to 140 days Characteristics of the Kudlac Soil Composition Typical profile: Lankbush soil and similar inclusions—90 percent 0 to 4 inches—light gray silty clay Contrasting inclusions—10 percent 4 to 7 inches—light gray clay Setting 7 to 11 inches—pale brown loam 11 to 14 inches—brown sandy loam Position on landscape: Terraces and foot slopes 14 to 27 inches—brown silty clay loam Elevation: 3,000 to 5,500 feet 27 to 30 inches—white silty clay loam Average annual precipitation: 9 to 12 inches 30 to 43 inches—brown silty clay loam Average annual air temperature: 46 to 48 43 to 60 inches—grayish brown silty clay degrees F Depth class: Very deep Frost-free season: 100 to 140 days Drainage class: Well drained Characteristics of the Lankbush Soil Permeability: Very slow Available water capacity: 8 to 10 inches Typical profile: Potential rooting depth: 60 inches or more 0 to 6 inches—brown loamy sand Runoff: Rapid 6 to 20 inches—brown sandy clay loam Hazard of water erosion: Severe 20 to 38 inches—light yellowish brown sandy Hazard of wind erosion: Moderate loam Shrink-swell potential: High 38 to 46 inches—light yellowish brown loamy Salinity throughout profile: Low or moderate sand 46 to 60 inches—very pale brown loamy Contrasting Inclusions sand Antelope Springs soils on lower lying terraces; 60 to 65 inches—very pale brown sandy Blacknest and Purdam soils on the sides of loam terraces; Fathom soils on terraces and Depth class: Very deep Jerome-Twin Falls, Idaho 73

Drainage class: Well drained tillage at a minimum, and keeping the surface of Permeability: Moderately slow the soil rough. Available water capacity: 4.0 to 6.5 inches Interpretive Groups Potential rooting depth: 60 inches or more Runoff: Slow Land capability classification: IIIe, irrigated, and Hazard of water erosion: Slight VIe, nonirrigated Hazard of wind erosion: Severe Range site: Sand, 8 to 12 inch precipitation zone Shrink-swell potential: Moderate Contrasting Inclusions 64—Lud silt loam, 2 to 10 percent Arbidge soils on lower lying terraces; Banbury slopes and Chuska soils on dip slopes and higher lying terraces; barren areas that are 10 to 20 Composition feet in diameter and are saline, are shallow Lud soil and similar inclusions—85 percent and clayey, or are subject to ant activity Contrasting inclusions—15 percent Use and Management Setting Major uses: Rangeland, irrigated cropland Position on landscape: Terraces Major management factors: Precipitation, Elevation: 4,500 to 5,300 feet permeability, slope, hazard of wind erosion Average annual precipitation: 9 to 11 inches Rangeland Average annual air temperature: 45 to 47 degrees F Dominant vegetation in natural potential plant Frost-free season: 100 to 120 days community: Indian ricegrass, needleandthread, basin big sagebrush Characteristics of the Lud Soil General management considerations: Typical profile: • Forage production is limited by low 0 to 2 inches—pale brown silt loam precipitation. 2 to 11 inches—pale brown silty clay loam • Seeding is limited by low precipitation and the 11 to 16 inches—very pale brown gravelly severe hazard of wind erosion. loam • Seeding generally is most successful late in 16 to 26 inches—white fractured lime- and fall, however, it may not be successful in years silica-cemented hardpan when precipitation is below average during the 26 inches—fractured bedrock growing season. Depth class: Shallow to a hardpan • Seeding burned or disturbed areas helps to Drainage class: Well drained control blowing and drifting sand. Permeability: Slow Available water capacity: 2.5 to 4.0 inches Irrigated Cropland Potential rooting depth: 10 to 20 inches General management considerations: Runoff: Medium • Most climatically suited crops can be grown if Hazard of water erosion: Moderate irrigation water is provided. Shrink-swell potential: High • Sprinkler irrigation is suited to this soil. Contrasting Inclusions • Because of the moderately slow permeability, the application of irrigation water should be Chuska, Owsel, Power, Roseworth, and Shano adjusted to the water intake rate. soils on lower lying terraces; soils that are • Production of irrigated crops is limited by deep to a hardpan, are silt loam over silty slope. clay loam, and are on terraces • Regulating irrigation water helps to control Use and Management runoff and erosion. • The risk of wind erosion is reduced by Major use: Rangeland maintaining crop residue on the surface, keeping Major management factors: Precipitation, depth 74 Soil Survey

to the hardpan, available water capacity, Available water capacity: 2.5 to 4.0 inches hazard of water erosion Potential rooting depth: 10 to 20 inches Dominant vegetation in natural potential plant Runoff: Medium community: Bluebunch wheatgrass, Hazard of water erosion: Moderate Wyoming big sagebrush Shrink-swell potential: High General management considerations: Contrasting Inclusions • Forage production is limited by low precipitation, shallow rooting depth, and low Chuska, Elijah, Owsel, and Roseworth soils on available water capacity. lower lying terraces; soils that are • Seeding is limited by low precipitation and the moderately deep to a hardpan, are silt loam moderate hazard of water erosion. over silty clay loam, and are on terraces • Seeding generally is most successful late in Use and Management fall; however, it may not be successful in years when precipitation is below average during the Major use: Rangeland growing season. Major management factors: Precipitation, depth to the hardpan, available water capacity, rock Interpretive Groups fragments in the surface layer, hazard of Land capability classification: VIs, nonirrigated water erosion Range site: Loamy, 10 to 13 inch precipitation Dominant vegetation in natural potential plant zone community: Bluebunch wheatgrass, Wyoming big sagebrush General management considerations: 65—Lud very cobbly silt loam, 2 to 10 • Forage production is limited by low percent slopes precipitation, shallow rooting depth, and low available water capacity. Composition • Seeding is limited by low precipitation, the rock fragments in the surface layer, and the moderate Lud soil and similar inclusions—85 percent hazard of water erosion. Contrasting inclusions—15 percent • The use of equipment is limited by the rock Setting fragments in the surface layer. Position on landscape: Terraces Interpretive Groups Elevation: 4,500 to 5,300 feet Land capability classification: VIIs, nonirrigated Average annual precipitation: 9 to 11 inches Range site: Loamy, 10 to 13 inch precipitation Average annual air temperature: 45 to 47 zone degrees F Frost-free season: 100 to 120 days Characteristics of the Lud Soil 66—Mackey very gravelly loam, 8 to 30 percent slopes Typical profile: 0 to 3 inches—pale brown very cobbly silt Composition loam 3 to 9 inches—pale brown cobbly silty clay Mackey soil and similar inclusions—85 percent loam Contrasting inclusions—15 percent 9 to 15 inches—very pale brown cobbly silty Setting clay 15 to 21 inches—white fractured lime- and Position on landscape: Dip slopes silica-cemented hardpan Elevation: 4,300 to 5,500 feet 21 inches—bedrock Average annual precipitation: 10 to 13 inches Depth class: Shallow to a hardpan Average annual air temperature: 47 to 49 Drainage class: Well drained degrees F Permeability: Slow Frost-free season: 100 to 120 days Jerome-Twin Falls, Idaho 75

Characteristics of the Mackey Soil 67—Minidoka silt loam, 0 to 2 percent Typical profile: slopes 0 to 3 inches—pale brown very gravelly loam 3 to 10 inches—pale brown very gravelly Composition clay loam Minidoka soil and similar inclusions—90 percent 10 to 16 inches—very pale brown extremely Contrasting inclusions—10 percent gravelly loam 16 to 36 inches—very pale brown extremely Setting gravelly sandy loam Position on landscape: Terraces 36 inches—bedrock Elevation: 3,500 to 4,500 feet Depth class: Moderately deep to bedrock Average annual precipitation: 8 to 10 inches Drainage class: Well drained Average annual air temperature: 48 to 50 Permeability: Moderate degrees F Available water capacity: 2 to 3 inches Frost-free season: 120 to 140 days Potential rooting depth: 20 to 40 inches Runoff: Medium Characteristics of the Minidoka Soil Hazard of water erosion: Moderate Typical profile: Contrasting Inclusions 0 to 11 inches—light brownish gray silt loam 11 to 17 inches—light gray silt loam Chuska, Lankbush, Owsel, and Schnipper soils 17 to 23 inches—very pale brown silt loam on lower lying terraces; Flatron and Ragpie 23 to 40 inches—white lime- and silica- soils on ridges; soils that are shallow to cemented hardpan bedrock, are very gravelly loam over 40 inches—bedrock extremely gravelly loam, and are on dip Depth class: Moderately deep to a hardpan slopes; areas of Rock outcrop; barren areas Drainage class: Well drained that are 10 to 20 feet in diameter and are Permeability: Moderate saline, are shallow and clayey, or are subject Available water capacity: 3.5 to 8.0 inches to ant activity Potential rooting depth: 20 to 40 inches Use and Management Runoff: Slow Hazard of water erosion: Slight Major use: Rangeland Hazard of wind erosion: Moderate Major management factors: Precipitation, available water capacity, rock fragments in Contrasting Inclusions the surface layer, hazard of water erosion Chiara and Minveno soils on higher lying Dominant vegetation in natural potential plant terraces; Portneuf soils on lower lying community: Bluebunch wheatgrass, antelope terraces bitterbrush General management considerations: Use and Management • Forage production is limited by low Major use: Irrigated cropland precipitation and low available water capacity. Major management factor: Hazard of wind • Seeding is limited by low precipitation, rock erosion fragments in the surface layer, and the moderate General management considerations: hazard of water erosion. • Most climatically suited crops can be grown if irrigation water is provided. Interpretive Groups • Surface and sprinkler irrigation systems are Land capability classification: VIIs, nonirrigated suited to this soil. Range site: Gravelly loam, 10 to 13 inch • Production of irrigated crops is limited by the precipitation zone moderate hazard of wind erosion. 76 Soil Survey

• The risk of wind erosion is reduced by General management considerations: maintaining crop residue on the surface, keeping • Most climatically suited crops can be grown if tillage at a minimum, and keeping the surface of irrigation water is provided. the soil rough. • Surface and sprinkler irrigation systems are suited to this soil. Interpretive Groups • Production of irrigated crops is limited by the Land capability classification: IIIs, irrigated, and moderate hazard of wind erosion. VIs, nonirrigated • The risk of wind erosion is reduced by maintaining crop residue on the surface, keeping tillage at a minimum, and keeping the surface of 68—Minidoka silt loam, 2 to 4 percent the soil rough. slopes Interpretive Groups Composition Land capability classification: IIIe, irrigated, and VIs, nonirrigated Minidoka soil and similar inclusions—90 percent Contrasting inclusions—10 percent Setting 69—Minveno silt loam, 0 to 2 percent slopes Position on landscape: Terraces Elevation: 3,500 to 4,500 feet Composition Average annual precipitation: 8 to 10 inches Average annual air temperature: 48 to 50 Minveno soil and similar inclusions—90 percent degrees F Contrasting inclusions—10 percent Frost-free season: 120 to 140 days Setting Characteristics of the Minidoka Soil Position on landscape: Terraces Typical profile: Elevation: 3,500 to 4,500 feet 0 to 6 inches—pale brown silt loam Average annual precipitation: 8 to 12 inches 6 to 13 inches—pale brown silt loam Average annual air temperature: 48 to 50 13 to 26 inches—light gray silt loam degrees F 26 to 40 inches—white lime- and silica- Frost-free season: 120 to 140 days cemented hardpan Characteristics of the Minidoka Soil 40 inches—bedrock Depth class: Moderately deep to a hardpan Typical profile: Drainage class: Well drained 0 to 8 inches—light brownish gray silt loam Permeability: Moderate 8 to 18 inches—white silt loam Available water capacity: 3.5 to 8.0 inches 18 to 23 inches—white lime- and silica- Potential rooting depth: 20 to 40 inches cemented hardpan Runoff: Slow 23 inches—bedrock Hazard of water erosion: Slight Depth class: Shallow to a hardpan Hazard of wind erosion: Moderate Drainage class: Well drained Permeability: Moderate Contrasting Inclusions Available water capacity: 2 to 4 inches Bahem, Portneuf, and Sluka soils on lower lying Potential rooting depth: 10 to 20 inches terraces; Minveno soils on higher lying Runoff: Slow terraces; areas of Rock outcrop Hazard of water erosion: Slight Hazard of wind erosion: Moderate Use and Management Major use: Irrigated cropland Contrasting Inclusions Major management factor: Hazard of wind erosion Portneuf and Sluka soils on lower lying terraces Jerome-Twin Falls, Idaho 77

Use and Management Average annual precipitation: 8 to 12 inches Average annual air temperature: 48 to 50 Major uses: Irrigated cropland, rangeland degrees F Major management factors: Precipitation, depth Frost-free season: 120 to 140 days to the hardpan, available water capacity, hazard of wind erosion Characteristics of the Minveno Soil Irrigated Cropland Typical profile: 0 to 8 inches—pale brown silt loam General management considerations: 8 to 15 inches—very pale brown silt loam • Most climatically suited crops can be grown if 15 to 30 inches—white lime- and silica- irrigation water is provided. cemented hardpan • Surface and sprinkler irrigation systems are 30 inches—bedrock suited to this soil. Depth class: Shallow to a hardpan • Production of irrigated crops is limited by the Drainage class: Well drained shallow rooting depth, low available water Permeability: Moderate capacity, and moderate hazard of wind erosion. Available water capacity: 2 to 4 inches • The risk of wind erosion is reduced by Potential rooting depth: 10 to 20 inches maintaining crop residue on the surface, keeping Runoff: Medium tillage at a minimum, and keeping the surface of Hazard of water erosion: Moderate the soil rough. Hazard of wind erosion: Moderate Rangeland Contrasting Inclusions Dominant vegetation in natural potential plant Chuska, Dolman, and Minidoka soils on terraces; community: Bluebunch wheatgrass, Portneuf and Sluka soils on lower lying Wyoming big sagebrush terraces; areas of Rock outcrop General management considerations: • Forage production is limited by low Use and Management precipitation, shallow rooting depth, and low Major uses: Rangeland, irrigated cropland available water capacity. Major management factors: Precipitation, depth • Seeding is limited by low precipitation and the to the hardpan, available water capacity, moderate hazard of wind erosion. slope, hazard of water erosion, hazard of • Seeding generally is most successful late in wind erosion fall; however, it may not be successful in years when precipitation is below average during the Rangeland growing season. Dominant vegetation in natural potential plant Interpretive Groups community: Bluebunch wheatgrass, Wyoming big sagebrush Land capability classification: IVs, irrigated, and General management considerations: VIs, nonirrigated • Forage production is limited by low Range site: Shallow loamy, 8 to 12 inch precipitation, shallow rooting depth, and low precipitation zone available water capacity. • Seeding is limited by low precipitation and the 70—Minveno silt loam, 2 to 8 percent moderate hazards of water and wind erosion. slopes • Seeding generally is most successful late in fall; however, it may not be successful in years when precipitation is below average during the Composition growing season. Minveno soil and similar inclusions—90 percent Irrigated Cropland Contrasting inclusions—10 percent General management considerations: Setting • Most climatically suited crops can be grown if Position on landscape: Terraces irrigation water is provided. Elevation: 3,500 to 4,500 feet • Sprinkler irrigation is best suited to this soil, but 78 Soil Survey

surface irrigation can be used if the water is Contrasting Inclusions regulated to control erosion. Minidoka and Trevino soils on lower lying • Production of irrigated crops is limited by the terraces; soils that are very shallow to a shallow rooting depth, low available water hardpan, are silt loam, and are on terraces capacity, slope, and the moderate hazards of wind and water erosion. Use and Management • The risk of wind erosion is reduced by Major use: Rangeland maintaining crop residue on the surface, keeping Major management factors: Precipitation, depth tillage at a minimum, and keeping the surface of to the hardpan, available water capacity, rock the soil rough. fragments in the surface layer, hazard of • Regulating irrigation water helps to control water erosion, hazard of wind erosion runoff and erosion. Dominant vegetation in natural potential plant Interpretive Groups community: Bluebunch wheatgrass, Wyoming big sagebrush Land capability classification: IVe, irrigated, and General management considerations: VIe, nonirrigated • Forage production is limited by low Range site: Shallow loamy, 8 to 12 inch precipitation, shallow rooting depth, and low precipitation zone available water capacity. • Seeding is limited by low precipitation, rock 71—Minveno very stony silt loam, 2 fragments in the surface layer, and the moderate to 20 percent slopes hazards of water and wind erosion. • The use of equipment is limited by the rock fragments in the surface layer. Composition Interpretive Groups Minveno soil and similar inclusions—90 percent Contrasting inclusions—10 percent Land capability classification: VIIs, nonirrigated Range site: Shallow loamy, 8 to 12 inch Setting precipitation zone Position on landscape: Terraces Elevation: 3,500 to 4,500 feet Average annual precipitation: 8 to 12 inches 72—Mug very cobbly loam, 2 to 10 Average annual air temperature: 48 to 50 percent slopes degrees F Frost-free season: 120 to 140 days Composition Characteristics of the Minveno Soil Mug soil and similar inclusions—80 percent Contrasting inclusions—20 percent Typical profile: 0 to 2 inches—pale brown very stony silt Setting loam Position on landscape: Terraces 2 to 12 inches—pale brown silt loam Elevation: 5,600 to 6,300 feet 12 to 18 inches—light gray silt loam Average annual precipitation: 12 to 15 inches 18 to 26 inches—white lime- and silica- Average annual air temperature: 43 to 45 cemented hardpan degrees F 26 inches—bedrock Frost-free season: 90 to 100 days Depth class: Shallow to a hardpan Drainage class: Well drained Characteristics of the Mug Soil Permeability: Moderate Available water capacity: 1.5 to 3.5 inches Typical profile: Potential rooting depth: 10 to 20 inches 0 to 5 inches—grayish brown very cobbly Runoff: Medium loam Hazard of water erosion: Moderate 5 to 14 inches—grayish brown extremely Hazard of wind erosion: Moderate gravelly clay loam Jerome-Twin Falls, Idaho 79

14 to 25 inches—brown gravelly clay Setting 25 inches—bedrock Position on landscape: Terraces Depth class: Moderately deep to bedrock Elevation: 5,500 to 6,100 feet Drainage class: Well drained Average annual precipitation: 12 to 16 inches Permeability: Very slow Average annual air temperature: 42 to 45 Available water capacity: 2.5 to 4.0 inches degrees F Potential rooting depth: 20 to 30 inches Frost-free season: 90 to 105 days Runoff: Medium Hazard of water erosion: Moderate Characteristics of the Oshone Soil Shrink-swell potential: High Typical profile: Contrasting Inclusions 0 to 5 inches—grayish brown clay loam 5 to 16 inches—brown clay Budlewis, Howcree, and Tanner soils on lower 16 to 22 inches—dark yellowish brown very lying terraces; Eep soils on hill slopes; Isknat gravelly clay soils on fan terraces; soils that are 22 to 31 inches—very pale brown lime- and moderately deep to bedrock, are cobbly loam silica-cemented hardpan over gravelly clay loam over gravelly clay, 31 to 60 inches—variegated very gravelly and are on terraces; soils that are shallow to sand bedrock, are very cobbly loam over Depth class: Moderately deep to a hardpan extremely gravelly clay loam over gravelly Drainage class: Well drained clay, and are on terraces Permeability: Very slow Use and Management Available water capacity: 4.0 to 6.5 inches Potential rooting depth: 20 to 40 inches Major use: Rangeland Runoff: Medium Major management factors: Precipitation, depth Hazard of water erosion: Moderate to the clayey subsoil, rock fragments in the Shrink-swell potential: High surface layer, hazard of water erosion Dominant vegetation in natural potential plant Contrasting Inclusions community: Idaho fescue, low sagebrush Amboat and Brose soils on summits; Chayson General management considerations: soils on terraces; Congle soils on foot slopes; • Forage production is limited by low Doodlelink soils on breaks; Ruclick soils on precipitation and shallow rooting depth. dip slopes; Tucker soils on flood plains; very • Plant rooting depth is limited to the upper part deep, poorly drained soils that are clay loam of the soil because of the claypan. over clay over very gravelly clay and are in • Seeding is limited by low precipitation, rock depressional areas of terraces; areas of fragments in the surface layer, and the moderate Rock outcrop hazard of water erosion. • The use of equipment is limited by the rock Use and Management fragments in the surface layer. Major use: Rangeland Interpretive Groups Major management factors: Hazard of water erosion Land capability classification: VIIs, nonirrigated Dominant vegetation in natural potential plant Range site: Shallow claypan, 12 to 16 inch community: Idaho fescue, mountain big precipitation zone sagebrush General management considerations: 73—Oshone clay loam, 2 to 8 percent • Seeding is limited by the moderate hazard of slopes water erosion. Interpretive Groups Composition Land capability classification: IVs, nonirrigated Oshone soil and similar inclusions—85 percent Range site: Loamy, 13 to 16 inch precipitation Contrasting inclusions—15 percent zone 80 Soil Survey

74—Oshone complex, 2 to 10 percent Drainage class: Well drained slopes Permeability: Very slow Available water capacity: 3 to 5 inches Potential rooting depth: 20 to 40 inches Composition Runoff: Medium Oshone soil and similar inclusions—45 percent Hazard of water erosion: Moderate Oshone soil, eroded, and similar inclusions—40 Shrink-swell potential: High percent Contrasting Inclusions Contrasting inclusions—15 percent Aninto, Chayson, and Tanner soils in lower lying Setting areas of terraces; very deep, poorly drained Position on landscape: Terraces soils that are clay loam over clay over very Elevation: 5,600 to 6,100 feet gravelly clay and are in depressional areas Average annual precipitation: 12 to 16 inches of terraces Average annual air temperature: 42 to 45 Use and Management degrees F Frost-free season: 90 to 105 days Major use: Rangeland Major management factors: Depth to the clayey Characteristics of the Oshone Soil subsoil in the Oshone soil, eroded; hazard of Typical profile: water erosion 0 to 6 inches—grayish brown and brown clay Dominant vegetation in natural potential plant loam community: Oshone soil—Idaho fescue, 6 to 16 inches—brown clay mountain big sagebrush; Oshone soil, 16 to 27 inches—brown gravelly clay eroded—Idaho fescue, low sagebrush 27 to 38 inches—light brown very gravelly General management considerations: clay loam • Forage production is limited by the shallow 38 to 47 inches—very pale brown lime- and rooting depth of the eroded Oshone soil. silica-cemented hardpan • Plant rooting depth is limited to the upper part 47 to 60 inches—weakly cemented very of the eroded Oshone soil because of the gravelly sand claypan. Depth class: Moderately deep to a hardpan • Seeding is limited by the moderate hazard of Drainage class: Well drained water erosion. Permeability: Very slow Interpretive Groups Available water capacity: 3 to 5 inches Potential rooting depth: 20 to 40 inches Land capability classification: IVs, nonirrigated Runoff: Medium Range site: Oshone soil—Loamy, 13 to 16 inch Hazard of water erosion: Moderate precipitation zone; Oshone soil, eroded— Shrink-swell potential: High Shallow claypan, 12 to 16 inch precipitation zone Characteristics of the Oshone Soil, Eroded 75—Owsel silt loam, 0 to 2 percent Typical profile: slopes 0 to 5 inches—brown clay loam 5 to 12 inches—brown gravelly clay Composition 12 to 20 inches—dark yellowish brown clay 20 to 24 inches—very pale brown very Owsel soil and similar inclusions—95 percent gravelly clay Contrasting inclusions—5 percent 24 to 34 inches—very pale brown lime- and Setting silica-cemented hardpan 34 to 70 inches—variegated very gravelly Position on landscape: Terraces sand Elevation: 5,100 to 5,200 feet Depth class: Moderately deep to a hardpan Average annual precipitation: 10 to 12 inches Jerome-Twin Falls, Idaho 81

Average annual air temperature: 47 to 48 Setting degrees F Position on landscape: Terraces Frost-free season: 110 to 120 days Elevation: 3,500 to 5,500 feet Characteristics of the Owsel Soil Average annual precipitation: 8 to 12 inches Average annual air temperature: 47 to 50 Typical profile: degrees F 0 to 9 inches—brown silt loam Frost-free season: 110 to 140 days 9 to 18 inches—pale brown silty clay loam 18 to 26 inches—pale brown silt loam Characteristics of the Owsel Soil 26 to 52 inches—light gray silt loam Typical profile: 52 to 68 inches—pale brown very fine sandy 0 to 4 inches—light brownish gray silt loam loam 4 to 18 inches—pale brown silt loam Depth class: Very deep 18 to 28 inches—pale brown silty clay loam Drainage class: Well drained 28 to 42 inches—very pale brown silt loam Permeability: Moderately slow 42 to 60 inches—very pale brown silt loam Available water capacity: 8.5 to 10.0 inches Depth class: Very deep Potential rooting depth: 60 inches or more Drainage class: Well drained Runoff: Slow Permeability: Moderately slow Hazard of water erosion: Slight Available water capacity: 8.5 to 10.0 inches Shrink-swell potential: Moderate Potential rooting depth: 60 inches or more Contrasting Inclusions Runoff: Slow Hazard of water erosion: Slight Lud soils on terraces, very deep soils that are silt Shrink-swell potential: Moderate loam over silty clay over silt loam and are on terraces Contrasting Inclusions Use and Management Bahem, Purdam, and Rad soils on lower lying terraces; very deep soils that are silt loam Major use: Rangeland over silty clay over silt loam and are on Major management factor: Precipitation terraces Dominant vegetation in natural potential plant community: Bluebunch wheatgrass, Use and Management Wyoming big sagebrush Major uses: Rangeland, irrigated cropland General management considerations: Major management factors: Precipitation, • Forage production and seeding are limited permeability, weak cementation mainly by low precipitation. • Seeding generally is most successful late in Rangeland fall; however, it may not be successful in years Dominant vegetation in natural potential plant when precipitation is below average during the community: Bluebunch wheatgrass, growing season. Wyoming big sagebrush Interpretive Groups General management considerations: • Forage production and seeding are limited Land capability classification: VIc, nonirrigated mainly by low precipitation. Range site: Loamy, 8 to 12 inch precipitation • Seeding generally is most successful late in zone fall; however, it may not be successful in years when precipitation is below average during the 76—Owsel silt loam, 2 to 4 percent growing season. slopes Irrigated Cropland General management considerations: Composition • Most climatically suited crops can be grown if Owsel soil and similar inclusions—90 percent irrigation water is provided. Contrasting inclusions—10 percent • Surface and sprinkler irrigation systems are 82 Soil Survey

suited to this soil. Use and Management • Because of the moderately slow permeability, Major uses: Rangeland, irrigated cropland the application of irrigation water should be Major management factors: Precipitation, adjusted to the water intake rate. permeability, weak cementation, slope, • Roots are restricted below a depth of 15 to 30 hazard of water erosion inches because of the weak silica cementation. • Deep chiseling or ripping improves the rooting Rangeland depth of the soil. Dominant vegetation in natural potential plant Interpretive Groups community: Bluebunch wheatgrass, Wyoming big sagebrush Land capability classification: IIe, irrigated, and General management considerations: VIc, nonirrigated • Forage production is limited by low Range site: Loamy, 8 to 12 inch precipitation precipitation. zone • Seeding is limited by low precipitation and the moderate hazard of water erosion. 77—Owsel silt loam, 4 to 8 percent • Seeding generally is most successful late in slopes fall; however, it may not be successful in years when precipitation is below average during the growing season. Composition Irrigated Cropland Owsel soil and similar inclusions—90 percent Contrasting inclusions—10 percent General management considerations: • Most climatically suited crops can be grown if Setting irrigation water is provided. Position on landscape: Sides of terraces • Sprinkler irrigation is best suited to this soil, but Elevation: 3,500 to 5,500 feet surface irrigation can be used if the water is Average annual precipitation: 8 to 12 inches regulated to control erosion. Average annual air temperature: 47 to 50 • Because of the moderately slow permeability, degrees F the application of irrigation water should be Frost-free season: 110 to 140 days adjusted to the water intake rate. • Roots are restricted below a depth of 15 to 30 Characteristics of the Owsel Soil inches because of the weak silica cementation. Typical profile: • Deep chiseling or ripping improves the rooting 0 to 9 inches—pale brown silt loam depth of the soil. 9 to 18 inches—pale brown silty clay loam • Production of irrigated crops is limited by 18 to 26 inches—pale brown silt loam slope. 26 to 52 inches—very pale brown loam • Regulating the application of irrigation water 52 to 68 inches—very pale brown sandy helps to control runoff and erosion. loam Interpretive Groups Depth class: Very deep Drainage class: Well drained Land capability classification: IIIe, irrigated, and Permeability: Moderately slow VIe, nonirrigated Available water capacity: 8.5 to 10.0 inches Range site: Loamy, 8 to 12 inch precipitation Potential rooting depth: 60 inches or more zone Runoff: Medium Hazard of water erosion: Moderate Shrink-swell potential: Moderate 78—Owsel silt loam, 8 to 12 percent slopes Contrasting Inclusions Composition Kecko, Portneuf, and Sluka soils on lower lying terraces; Purdam and Rad soils on the sides Owsel soil and similar inclusions—90 percent of terraces Contrasting inclusions—10 percent Jerome-Twin Falls, Idaho 83

Setting 79—Owsel silt loam, 12 to 20 percent Position on landscape: Sides of terraces slopes Elevation: 3,500 to 5,500 feet Average annual precipitation: 8 to 12 inches Composition Average annual air temperature: 47 to 50 Owsel soil and similar inclusions—90 percent degrees F Contrasting inclusions—10 percent Frost-free season: 110 to 140 days Setting Characteristics of the Owsel Soil Position on landscape: Sides of terraces Typical profile: Elevation: 3,500 to 5,500 feet 0 to 9 inches—pale brown silt loam Average annual precipitation: 8 to 12 inches 9 to 18 inches—pale brown silty clay loam Average annual air temperature: 47 to 50 18 to 26 inches—pale brown silt loam degrees F 26 to 52 inches—very pale brown loam Frost-free season: 110 to 140 days 52 to 68 inches—very pale brown sandy loam Characteristics of the Owsel Soil Depth class: Very deep Typical profile: Drainage class: Well drained 0 to 8 inches—brown silt loam Permeability: Moderately slow 8 to 39 inches—pale brown silt loam Available water capacity: 8.5 to 10.0 inches 39 to 65 inches—very pale brown silt loam Potential rooting depth: 60 inches or more Depth class: Very deep Runoff: Medium Drainage class: Well drained Hazard of water erosion: Moderate Permeability: Moderately slow Shrink-swell potential: Moderate Available water capacity: 8.5 to 10.0 inches Contrasting Inclusions Potential rooting depth: 60 inches or more Runoff: Medium Purdam soils on the sides of terraces Hazard of water erosion: Moderate Use and Management Contrasting Inclusions Major use: Rangeland Major management factors: Precipitation, hazard Purdam soils on the sides of terraces of water erosion Dominant vegetation in natural potential plant Use and Management community: Bluebunch wheatgrass, Wyoming big sagebrush Major use: Rangeland General management considerations: Major management factors: Precipitation, hazard • Forage production is limited by low of water erosion precipitation. Dominant vegetation in natural potential plant • Seeding is limited by low precipitation and the community: Bluebunch wheatgrass, moderate hazard of water erosion. Wyoming big sagebrush • Seeding generally is most successful late in General management considerations: fall; however, it may not be successful in years • Forage production is limited by low when precipitation is below average during the precipitation. growing season. • Seeding is limited by low precipitation and the moderate hazard of water erosion. Interpretive Groups • Seeding generally is most successful late in Land capability classification: VIe, nonirrigated fall; however, it may not be successful in years Range site: Loamy, 8 to 12 inch precipitation when precipitation is below average during the zone growing season. 84 Soil Survey

Interpretive Groups General management considerations: • Forage production is limited by low Land capability classification: VIe, nonirrigated precipitation. Range site: Loamy, 8 to 12 inch precipitation • Seeding is limited by low precipitation and zone moderate hazard of wind erosion. • Seeding generally is most successful late in 80—Paniogue loam, 0 to 2 percent fall; however, it may not be successful in years slopes when precipitation is below average during the growing season. Composition Irrigated Cropland Paniogue soil and similar inclusions—95 percent General management considerations: Contrasting inclusions—5 percent • Most climatically suited crops can be grown if irrigation water is provided. Setting • Surface and sprinkler irrigation systems are Position on landscape: Terraces suited to this soil. Elevation: 2,800 to 4,000 feet • Production of irrigated crops is limited by the Average annual precipitation: 8 to 10 inches moderate hazard of wind erosion. Average annual air temperature: 49 to 51 • The risk of wind erosion is reduced by degrees F maintaining crop residue on the surface, keeping Frost-free season: 120 to 140 days tillage at a minimum, and keeping the surface of the soil rough. Characteristics of the Paniogue Soil Interpretive Groups Typical profile: 0 to 7 inches—pale brown loam Land capability classification: IIc, irrigated, and 7 to 11 inches—light brownish gray loam VIc, nonirrigated 11 to 16 inches—brown loam Range site: Loamy, 8 to 10 inch precipitation 16 to 22 inches—light brownish gray gravelly zone sandy loam 22 to 60 inches—variegated sand and gravel Depth class: Very deep 81—Paniogue loam, 2 to 4 percent Drainage class: Well drained slopes Permeability: Moderate Available water capacity: 5.0 to 7.5 inches Composition Potential rooting depth: 20 to 40 inches Portneuf soil and similar inclusions—95 percent Runoff: Slow Contrasting inclusions—5 percent Hazard of water erosion: Slight Hazard of wind erosion: Moderate Setting Contrasting Inclusions Position on landscape: Terraces Elevation: 2,800 to 4,000 feet Owsel soils on lower lying terraces; Taunton and Average annual precipitation: 8 to 10 inches Scoon soils on higher lying terraces Average annual air temperature: 49 to 51 Use and Management degrees F Frost-free season: 120 to 140 days Major uses: Rangeland, irrigated cropland Major management factors: Precipitation, hazard Characteristics of the Paniogue Soil of wind erosion Typical profile: Rangeland 0 to 5 inches—yellowish brown loam 5 to 25 inches—light yellowish brown very Dominant vegetation in natural potential plant fine sandy loam community: Thurber needlegrass, Wyoming 25 to 35 inches—very pale brown sandy big sagebrush loam Jerome-Twin Falls, Idaho 85

35 to 60 inches—multicolored very gravelly Characteristics of the Paulville Soil sand Typical profile: Depth class: Very deep 0 to 8 inches—brown silt loam Drainage class: Well drained 8 to 22 inches—pale brown clay loam Permeability: Moderate 22 to 28 inches—pale brown loam Available water capacity: 5.0 to 7.5 inches 28 to 60 inches—very pale brown silt loam Potential rooting depth: 20 to 40 inches Depth class: Very deep Runoff: Slow Drainage class: Well drained Hazard of water erosion: Slight Permeability: Moderately slow Hazard of wind erosion: Moderate Available water capacity: 9.0 to 10.5 inches Contrasting Inclusions Potential rooting depth: 60 inches or more Runoff: Slow Banbury soils on higher lying terraces Hazard of water erosion: Slight Use and Management Shrink-swell potential: Moderate Major use: Irrigated cropland Contrasting Inclusions Major management factor: Hazard of wind erosion Arbidge soils on terraces, Chuska soils on higher General management considerations: lying terraces, Tulch soils on stream terraces • Most climatically suited crops can be grown if irrigation water is provided. Use and Management • Surface and sprinkler irrigation systems are suited to this soil. Major use: Rangeland • Production of irrigated crops is limited by the Major management factor: Precipitation moderate hazard of wind erosion. Dominant vegetation in natural potential plant • The risk of wind erosion is reduced by community: Bluebunch wheatgrass, maintaining crop residue on the surface, keeping Wyoming big sagebrush tillage at a minimum, and keeping the surface of General management considerations: the soil rough. • Forage production and seeding are limited Interpretive Groups mainly by low precipitation. • Seeding generally is most successful late in Land capability classification: IIe, irrigated, and fall; however, it may not be successful in years VIc, nonirrigated when precipitation is below average during the growing season. 82—Paulville silt loam, 0 to 2 percent slopes Interpretive Groups Land capability classification: VIc, nonirrigated Composition Range site: Loamy, 8 to 12 inch precipitation Paulville soil and similar inclusions—90 percent zone Contrasting inclusions—10 percent

Setting 83—Paulville-Idow complex, 1 to 4 percent slopes Position on landscape: Terraces Elevation: 3,500 to 5,000 feet Composition Average annual precipitation: 8 to 11 inches Average annual air temperature: 47 to 51 Paulville soil and similar inclusions—50 percent degrees F Idow soil and similar inclusions—30 percent Frost-free season: 110 to 140 days Contrasting inclusions—20 percent 86 Soil Survey

Setting over silty clay loam over silt loam, and are on terraces; areas of Rock outcrop Position on landscape: Terraces Elevation: 3,500 to 4,000 feet Use and Management Average annual precipitation: 9 to 10 inches Average annual air temperature: 47 to 49 Major use: Irrigated cropland degrees F Major management factor: Permeability Frost-free season: 130 to 140 days General management considerations: • Most climatically adapted crops can be grown Characteristics of the Paulville Soil if irrigation water is provided. Typical profile: • Surface and sprinkler irrigation systems are 0 to 8 inches—brown loam suited to this soil. 8 to 31 inches—yellowish brown loam • Because of the moderately slow permeability, 31 to 40 inches—very pale brown loam the application of irrigation water should be 40 to 47 inches—light yellowish brown loam adjusted to the water intake rate. 47 to 60 inches—pale brown gravelly loam Depth class: Very deep Interpretive Groups Drainage class: Well drained Land capability classification: IIe, irrigated, and Permeability: Moderately slow VIs, nonirrigated Available water capacity: 9.0 to 10.5 inches Potential rooting depth: 60 inches or more Runoff: Slow 84—Pits, gravel Hazard of water erosion: Slight Shrink-swell potential: Moderate Description of areas: Small to large open excavations 2 to 20 feet deep or more where Characteristics of the Idow Soil gravel, cinders, soil material, or bedrock was Typical profile: removed for construction purposes 0 to 23 inches—yellowish brown loam Location in survey area: Areas ranging from 23 to 39 inches—very pale brown silt loam 2,900 feet in elevation along the Snake River 39 to 60 inches—very pale brown fractured to 6,000 feet in the Shoshone Basin lime- and silica-cemented hardpan Vegetation: Little, if any Depth class: Moderately deep to a hardpan Land capability classification: VIII Drainage class: Well drained Permeability: Moderately slow Available water capacity: 5 to 8 inches 85—Player-Rock outcrop complex, 30 Potential rooting depth: 20 to 40 inches to 75 percent slopes Runoff: Slow Composition Hazard of water erosion: Slight Shrink-swell potential: Moderate Player soil and similar inclusions—30 percent Player soil, thick surface, and similar inclusions— Contrasting Inclusions 25 percent Bahem, Rad, and Shano soils on lower lying Rock outcrop—30 percent terraces; Barrymore, Sluka, Starbuck, and Contrasting inclusions—15 percent Taunton soils on higher lying terraces; Elijah, Emberton, Harsan, Kecko, and Sidlake soils Setting on terraces; Tulch soils on stream terraces; soils that are moderately deep to a hardpan, Position on landscape: Player soil—convex areas are loam over heavy clay loam over loam, of breaks, Player soil, thick surface— and are on terraces; soils that are concave areas of breaks (see fig. 7 next moderately deep to a hardpan, are silt loam page) Jerome-Twin Falls, Idaho 87

Characteristics of the Player Soil, Thick Surface Slope range: 30 to 50 percent Typical profile: 0 to 9 inches—dark grayish brown very cobbly loam 9 to 17 inches—grayish brown very gravelly clay 17 to 60 inches—light brown extremely gravelly clay Depth class: Very deep Drainage class: Well drained Permeability: Very slow Available water capacity: 5 to 7 inches Potential rooting depth: 60 inches or more Runoff: Rapid Hazard of water erosion: Very severe Figure 7.—Area of Player-Rock outcrop complex, 30 to Shrink-swell potential: High 75 percent slopes, on breaks. Characteristics of the Rock Outcrop Elevation: 5,400 to 6,400 feet Kind of rock: Exposed welded tuff Average annual precipitation: 12 to 15 inches Description of areas: Sharp, angular cliffs and Average annual air temperature: 40 to 44 rimrock that border lower lying valley degrees F terraces and large, angular fragments Frost-free season: 70 to 80 days randomly deposited downslope Contrasting Inclusions Characteristics of the Player Soil Dehana and Doodlelink soils on breaks; Elhina Slope range: 30 to 75 percent soils on lower lying terraces; Hogmalat and Typical profile: Keman soils on summits; Isknat soils on fan 0 to 5 inches—dark grayish brown very terraces; very deep soils that are gravelly gravelly loam loam over gravelly clay and are on breaks 5 to 11 inches—dark grayish brown very Use and Management gravelly clay 11 to 22 inches—brown extremely gravelly Major use: Rangeland clay Major management factors: Depth to the clayey 22 to 45 inches—light yellowish brown subsoil, slope, hazard of water erosion, extremely gravelly clay areas of Rock outcrop 45 to 60 inches—light brown extremely Dominant vegetation in natural potential plant gravelly clay community: Player soil—Idaho fescue, low Depth class: Very deep sagebrush; Player soil, thick surface— Drainage class: Well drained bluebunch wheatgrass, mountain big Permeability: Very slow sagebrush Available water capacity: 4 to 6 inches General management considerations: Potential rooting depth: 60 inches or more • Forage production is limited by the shallow Runoff: Rapid rooting depth of the Player soil. Hazard of water erosion: Very severe • The use of forage is limited by slope and the Shrink-swell potential: High areas of Rock outcrop. 88 Soil Survey

• Seeding is limited by the shallow depth to the Use and Management clayey subsoil in the Player soil, slope, the areas Major use: Irrigated cropland of Rock outcrop, and the very severe hazard of Major management factors: Permeability, weak water erosion. cementation, hazard of wind erosion • The use of equipment is limited by slope and General management considerations: the areas of Rock outcrop. • Most climatically suited crops can be grown if Interpretive Groups irrigation water is provided. • Surface and sprinkler irrigation systems are Land capability classification: VIIe, nonirrigated suited to this soil. Range site: Player soil—Shallow claypan, 12 to • Because of the moderately slow permeability, 16 inch precipitation zone; Player soil, thick the application of irrigation water should be surface—North slope stony, 12 to 16 inch adjusted to the water intake rate. precipitation zone • Roots are restricted below a depth of 12 to 30 inches because of the weak silica cementation. 86—Portneuf silt loam, 0 to 2 percent • Deep chiseling or ripping improves the rooting slopes depth. • The risk of wind erosion is reduced by maintaining crop residue on the surface, keeping Composition tillage at a minimum, and keeping the soil rough. Portneuf soil and similar inclusions—95 percent Interpretive Groups Contrasting inclusions—5 percent Land capability classification: IIc, irrigated, and Setting VIc, nonirrigated Position on landscape: Terraces Elevation: 3,000 to 4,500 feet 87—Portneuf silt loam, 2 to 4 percent Average annual precipitation: 8 to 10 inches slopes Average annual air temperature: 48 to 51 degrees F Composition Frost-free season: 110 to 140 days Portneuf soil and similar inclusions—95 percent Characteristics of the Portneuf Soil Contrasting inclusions—5 percent Typical profile: Setting 0 to 11 inches—light brownish gray silt loam Position on landscape: Terraces 11 to 34 inches—very pale brown silt loam Elevation: 3,000 to 4,500 feet 34 to 60 inches—light yellowish brown silt Average annual precipitation: 8 to 10 inches loam Average annual air temperature: 48 to 51 Depth class: Very deep degrees F Drainage class: Well drained Frost-free season: 110 to 140 days Permeability: Moderately slow Available water capacity: 10.5 to 11.5 inches Characteristics of the Portneuf Soil Potential rooting depth: 60 inches or more Typical profile: Runoff: Slow 0 to 5 inches—light brownish gray silt loam Hazard of water erosion: Slight 5 to 15 inches—pale brown silt loam Hazard of wind erosion: Moderate 15 to 40 inches—very pale brown silt loam 40 to 60 inches—pale brown silt loam Contrasting Inclusions Depth class: Very deep Bahem and Sluka soils on terreaces; Power and Drainage class: Well drained Rad soils on lower lying terraces; soils that Permeability: Moderately slow are deep to a hardpan, are silt loam, and are Available water capacity: 10.5 to 11.5 inches on lower lying terraces; areas of Rock Potential rooting depth: 60 inches or more outcrop Runoff: Slow Jerome-Twin Falls, Idaho 89

Hazard of water erosion: Slight maintaining crop residue on the surface, keeping Hazard of wind erosion: Moderate tillage at a minimum, and keeping the surface of the soil rough. Contrasting Inclusions Interpretive Groups Bahem, Minidoka, and Sluka soils on terraces; Rad soils on lower lying terraces; soils that Land capability classification: IIe, irrigated, and are deep to a hardpan, are silt loam, and are VIc, nonirrigated on lower lying terraces; soils that are deep to bedrock, are silt loam, and are on higher 88—Portneuf silt loam, 4 to 8 percent lying terraces; areas of Rock outcrop slopes Use and Management Composition Major use: Irrigated cropland (fig. 8) Portneuf soil and similar inclusions—95 percent Contrasting inclusions—5 percent Setting Position on landscape: Sides of terraces Elevation: 3,000 to 4,500 feet Average annual precipitation: 8 to 10 inches Average annual air temperature: 48 to 51 degrees F Frost-free season: 110 to 140 days Characteristics of the Portneuf Soil Typical profile: 0 to 5 inches—light brownish gray silt loam 5 to 15 inches—pale brown silt loam 15 to 30 inches—light gray silt loam 30 to 60 inches—pale brown silt loam Depth class: Very deep Drainage class: Well drained Permeability: Moderately slow Available water capacity: 10.5 to 11.5 inches Figure 8.—Area of Portneuf silt loam, 2 to 4 percent Potential rooting depth: 60 inches or more slopes, used for pinto beans. Runoff: Medium Major management factors: Permeability, weak Hazard of water erosion: Moderate cementation, hazard of wind erosion Hazard of wind erosion: Moderate General management considerations: Contrasting Inclusions • Most climatically suited crops can be grown if irrigation water is provided. Bahem and Sluka soils on the sides of terraces, • Surface and sprinkler irrigation systems are areas of Rock outcrop suited to this soil. Use and Management • Because of the moderately slow permeability, the application of irrigation water should be Major uses: Irrigated cropland, rangeland adjusted to the water intake rate. Major management factors: Permeability, weak • Roots are restricted below a depth of 12 to 30 cementation, precipitation, slope, hazard of inches because of the weak silica cementation. water erosion, hazard of wind erosion • Deep chiseling or ripping improves the rooting Irrigated Cropland depth. • Production of irrigated crops is limited by the General management considerations: moderate hazard of wind erosion. • Most climatically suited crops can be grown if • The risk of wind erosion is reduced by irrigation water is provided. 90 Soil Survey

• Sprinkler irrigation is best suited to this soil, but Average annual air temperature: 48 to 51 surface irrigation can be used if the water is degrees F regulated to control erosion. Frost-free season: 110 to 140 days • Because of the moderately slow permeability, Characteristics of the Portneuf Soil the application of irrigation water should be adjusted to the water intake rate. Typical profile: • Roots are restricted below a depth of 12 to 30 0 to 7 inches—light brownish gray silt loam inches because of the weak silica cementation. 7 to 13 inches—pale brown silt loam • Deep chiseling or ripping improves the rooting 13 to 46 inches—light gray silt loam depth. 46 to 70 inches—pale brown silt loam • Production of irrigated crops is limited by slope Depth class: Very deep and the moderate hazards of water and wind Drainage class: Well drained erosion. Permeability: Moderately slow • Regulating irrigation water helps to control Available water capacity: 10.5 to 11.5 inches runoff and erosion. Potential rooting depth: 60 inches or more • The risk of wind erosion is reduced by Runoff: Medium maintaining crop residue on the surface, keeping Hazard of water erosion: Moderate tillage at a minimum, and keeping the surface of Hazard of wind erosion: Moderate the soil rough. Contrasting Inclusions Rangeland Bahem and Sluka soils on the sides of terraces Dominant vegetation in natural potential plant Use and Management community: Thurber needlegrass, Wyoming big sagebrush Major uses: Irrigated cropland, rangeland General management considerations: Major management factors: Permeability, weak • Forage production is limited by low cementation, precipitation, slope, hazard of precipitation. water erosion, hazard of wind erosion • Seeding is limited by low precipitation and the Irrigated Cropland moderate hazards of water and wind erosion. • Seeding generally is most successful late in General management considerations: fall; however, it may not be successful in years • Because areas of this soil are long and narrow, when precipitation is below average during the management is dependent on the major uses of growing season. the adjacent areas that are less sloping and wider. Interpretive Groups Rangeland Land capability classification: IIIe, irrigated, and VIe, nonirrigated Dominant vegetation in natural potential plant Range site: Loamy, 8 to 10 inch precipitation community: Thurber needlegrass, Wyoming zone big sagebrush General management considerations: • Forage production is limited by low 89—Portneuf silt loam, 8 to 12 precipitation percent slopes • Seeding is limited by low precipitation and the moderate hazards of water and wind erosion. Composition • Seeding generally is most successful late in fall; however, it may not be successful in years Portneuf soil and similar inclusions—95 percent when precipitation is below average during the Contrasting inclusions—5 percent growing season. Setting Interpretive Groups Position on landscape: Sides of terraces Elevation: 3,000 to 4,500 feet Land capability classification: IVe, irrigated, and Average annual precipitation: 8 to 10 inches VIe, nonirrigated Jerome-Twin Falls, Idaho 91

Range site: Loamy, 8 to 10 inch precipitation Interpretive Groups zone Land capability classification: IIe, irrigated, and VIc, nonirrigated 90—Power silt loam, 1 to 4 percent slopes 91—Power-McCain complex, 1 to 6 percent slopes Composition Power soil and similar inclusions—85 percent Composition Contrasting inclusions—15 percent Power soil and similar inclusions—50 percent Setting McCain soil and similar inclusions—30 percent Contrasting inclusions—20 percent Position on landscape: Terraces Elevation: 3,500 to 4,500 feet Setting Average annual precipitation: 9 to 11 inches Position on landscape: Power soil—concave Average annual air temperature: 47 to 49 areas of terraces, McCain soil—convex degrees F areas of terraces Frost-free season: 130 to 140 days Elevation: 3,500 to 4,500 feet Characteristics of the Power Soil Average annual precipitation: 9 to 10 inches Average annual air temperature: 47 to 49 Typical profile: degrees F 0 to 8 inches—brown silt loam Frost-free season: 130 to 140 days 8 to 18 inches—pale brown silty clay loam 18 to 60 inches—very pale brown silt loam Characteristics of the Power Soil Depth class: Very deep Typical profile: Drainage class: Well drained 0 to 6 inches—brown silt loam Permeability: Moderately slow 6 to 14 inches—brown silt loam Available water capacity: 11.0 to 12.5 inches 14 to 28 inches—yellowish brown silty clay Potential rooting depth: 60 inches or more loam Runoff: Slow 28 to 58 inches—very pale brown silt loam Hazard of water erosion: Slight 58 to 72 inches—pale brown silt loam Shrink-swell potential: Moderate Depth class: Very deep Contrasting Inclusions Drainage class: Well drained Permeability: Moderately slow Bahem, Hoosegow, and Kecko soils on terraces; Available water capacity: 11 to 12 inches Banbury, Barrymore, Dolman, Elijah, and Potential rooting depth: 60 inches or more McCain soils on higher lying terraces; Runoff: Slow Owinza soils in depressional areas of Hazard of water erosion: Slight terraces; Tulch soils on stream terraces Shrink-swell potential: Moderate Use and Management Characteristics of the McCain Soil Major use: Irrigated cropland Typical profile: Major management factor: Permeability 0 to 6 inches—brown silt loam General management considerations: 6 to 16 inches—yellowish brown silt loam • Most climatically suited crops can be grown if 16 to 23 inches—very pale brown silt loam irrigation water is provided. 23 inches—fractured bedrock • Surface and sprinkler irrigation systems are Depth class: Moderately deep to bedrock suited to this soil. Drainage class: Well drained • Because of the moderately slow permeability, Permeability: Moderately slow the application of irrigation water should be Available water capacity: 4.5 to 6.5 inches adjusted to the water intake rate. Potential rooting depth: 20 to 40 inches 92 Soil Survey

Runoff: Slow Rock outcrop—10 percent Hazard of water erosion: Slight Contrasting inclusions—10 percent Shrink-swell potential: Moderate Setting Contrasting Inclusions Position on landscape: Power soil—plane to Barrymore and Starbuck soils in convex areas of convex areas of terraces, Owinza soil— terraces; Hoosegow and Kecko soils on concave areas of terraces lower lying terraces; Owinza soils in Elevation: 3,500 to 4,500 feet depressional areas of terraces; soils that are Average annual precipitation: 9 to 11 inches shallow to bedrock, are silt loam, and are in Average annual air temperature: 48 to 51 convex areas of terraces; areas of Rock degrees F outcrop Frost-free season: 120 to 140 days Use and Management Characteristics of the Power Soil Major uses: Rangeland, irrigated cropland Slope range: 1 to 8 percent Major management factors: Precipitation, Typical profile: permeability 0 to 8 inches—pale brown silt loam 8 to 20 inches—light yellowish brown silt Rangeland loam Dominant vegetation on natural potential plant 20 to 34 inches—white loam community: Bluebunch wheatgrass, 34 to 60 inches—light yellowish brown silt Wyoming big sagebrush loam General management considerations: Depth class: Very deep • Forage production and seeding are limited Drainage class: Well drained mainly by low precipitation. Permeability: Moderately slow • Seeding generally is most successful late in Available water capacity: 10 to 12 inches fall; however, it may not be successful in years Potential rooting depth: 60 inches or more when precipitation is below average during the Runoff: Medium growing season. Hazard of water erosion: Moderate Shrink-swell potential: Moderate Irrigated Cropland Characteristics of the Owinza Soil General management considerations: • Most climatically suited crops can be grown if Slope range: 1 to 3 percent irrigation water is provided. Typical profile: • Surface and sprinkler irrigation systems are 0 to 4 inches—very pale brown silt loam suited to this soil. 4 to 10 inches—yellowish brown clay • Because of the moderately slow permeability, 10 to 16 inches—very pale brown clay the application of irrigation water should be 16 to 23 inches—white silty clay loam adjusted to the water intake rate. 23 to 63 inches—very pale brown loam Depth class: Very deep Interpretive Groups Drainage class: Well drained Land capability classification: IIIe, irrigated, and Permeability: Very slow VIe, nonirrigated Available water capacity: 6 to 8 inches Range site: Loamy, 8 to 12 inch precipitation Potential rooting depth: 60 inches or more zone Runoff: Slow Hazard of water erosion: Slight 92—Power-Owinza-Rock outcrop Shrink-swell potential: High complex, 1 to 8 percent slopes Salinity: Moderately saline between depths of 16 and 63 inches Composition Characteristics of the Rock Outcrop Power soil and similar inclusions—45 percent Owinza soil and similar inclusions—35 percent Kind of rock: Exposed basalt Jerome-Twin Falls, Idaho 93

Description of areas: Sharp, angular to • Production of irrigated crops is limited by the semirounded, long, narrow ridges ranging to moderate hazard of water erosion on the Power semirounded outcroppings that extend 1 foot soil and the areas of Rock outcrop. to 10 feet above the adjacent landscape • Regulating irrigation water helps to control runoff and erosion. Contrasting Inclusions Interpretive Groups Banbury, Barrymore, McCain, and Starbuck soils on higher lying terraces; Kecko, Purdam, and Land capability classification: IIIe, irrigated, and Shano soils on lower lying terraces; Tulch VIe, nonirrigated soils on stream terraces; soils that are Range site: Power soil—Loamy, 8 to 12 inch shallow to bedrock, are very cobbly loam precipitation zone; Owinza soil—Slick spot over very gravelly loam, and are on ridges; sodic, 8 to 12 inch precipitation zone very deep, poorly drained soils that are silt loam over silty clay and are in basins; barren 93—Purdam silt loam, 1 to 4 percent areas that are 10 to 20 feet in diameter and slopes are saline, are shallow and clayey, or are subject to ant activity Composition Use and Management Purdam soil and similar inclusions—90 percent Major uses: Rangeland, irrigated cropland Contrasting inclusions—10 percent Major management factors: Precipitation, Setting permeability, hazard of water erosion, areas of Rock outcrop Position on landscape: Terraces Elevation: 3,000 to 5,000 feet Rangeland Average annual precipitation: 8 to 11 inches Dominant vegetation in natural potential plant Average annual air temperature: 47 to 51 community: Power soil—bluebunch degrees F wheatgrass, Wyoming big sagebrush; Frost-free season: 110 to 140 days Owniza soil—bluebunch wheatgrass, basin Characteristics of the Purdam Soil big sagebrush General management considerations: Typical profile: • Forage production is limited by low 0 to 4 inches—brown silt loam precipitation. 4 to 8 inches—yellowish brown silt loam • Seeding is limited by low precipitation and the 8 to 15 inches—pale brown silty clay loam areas of Rock outcrop. 15 to 26 inches—light gray silt loam • Seeding generally is most successful late in 26 to 51 inches—white lime- and silica- fall; however, it may not be successful in years cemented hardpan over very pale brown when precipitation is below average during the loam growing season. 51 to 66 inches—very pale brown very fine • The use of equipment is limited by the areas of sandy loam Rock outcrop. Depth class: Moderately deep to a hardpan Drainage class: Well drained Irrigated Cropland Permeability: Moderately slow General management considerations: Available water capacity: 4.5 to 7.5 inches • Most climatically suited crops can be grown if Potential rooting depth: 20 to 40 inches irrigation water is provided. Runoff: Slow • Sprinkler irrigation is best suited to the Power Hazard of water erosion: Slight soil, but surface irrigation can be used if the Shrink-swell potential: Moderate water is regulated to control erosion. Contrasting Inclusions • Because of the moderately slow permeability of the Power soil and the very slow permeability Blacknest, Dolman, and Rakane soils on lower of the Owinza soil, the application of irrigation lying terraces; Power, Rad, Shano, and Sluka water should be adjusted to the water intake rate. soils on higher lying terraces; soils that are 94 Soil Survey

shallow to a hardpan, are silt loam over silty Characteristics of the Purdam Soil clay loam over silt loam, and are on higher Typical profile: lying terraces; areas of Rock outcrop 0 to 4 inches—brown silt loam Use and Management 4 to 7 inches—pale brown silt loam 7 to 14 inches—pale brown silty clay loam Major uses: Irrigated cropland, rangeland 14 to 20 inches—light yellowish brown silt Major management factors: Precipitation, loam permeability 20 to 33 inches—very pale brown silt loam Irrigated Cropland 33 to 70 inches—white lime- and silica- cemented hardpan over very pale brown General management considerations: silt loam • Most climatically suited crops can be grown if Depth class: Moderately deep to a hardpan irrigation water is provided. Drainage class: Well drained • Surface and sprinkler irrigation systems are Permeability: Moderately slow suited to this soil. Available water capacity: 4.5 to 7.5 inches • Because of the moderately slow permeability, Potential rooting depth: 20 to 40 inches the application of irrigation water should be Runoff: Medium adjusted to the water intake rate. Hazard of water erosion: Moderate Rangeland Shrink-swell potential: Moderate Dominant vegetation in natural potential plant Contrasting Inclusions community: Thurber needlegrass, Wyoming Blacknest, Rakane, and Sluka soils on lower big sagebrush lying terraces; Elijah, Power, and Shano soils General management considerations: on higher lying terraces; areas of Rock • Forage production and seeding are limited by outcrop low precipitation. • Seeding generally is most successful late in Use and Management fall; however, it may not be successful in years Major uses: Rangeland, irrigated cropland when precipitation is below average during the Major management factors: Precipitation, growing season. permeability, slope, hazard of water erosion Interpretive Groups Rangeland Land capability classification: IIIe, irrigated, and Dominant vegetation in natural potential plant VIs, nonirrigated community: Thurber needlegrass, Wyoming Range site: Loamy, 8 to 10 inch precipitation big sagebrush zone General management considerations: • Forage production is limited by low 94—Purdam silt loam, 4 to 8 percent precipitation. slopes • Seeding is limited by low precipitation and the moderate hazard of water erosion. • Seeding generally is most successful late in Composition fall; however, it may not be successful in years Purdam soil and similar inclusions—90 percent when precipitation is below average during the Contrasting inclusions—10 percent growing season. Setting Irrigated Cropland Position on landscape: Terraces General management considerations: Elevation: 3,500 to 5,000 feet • Most climatically suited crops can be grown if Average annual precipitation: 8 to 11 inches irrigation water is provided. Average annual air temperature: 47 to 51 • Sprinkler irrigation is best suited to this soil, but degrees F surface irrigation can be used if the water is Frost-free season: 110 to 140 days regulated to control erosion. Jerome-Twin Falls, Idaho 95

• Because of the moderately slow permeability, Use and Management the application of irrigation water should be Major use: Rangeland adjusted to the water intake rate. Major management factors: Precipitation, hazard • Production of irrigated crops is limited by slope of water erosion and the moderate hazard of water erosion. Dominant vegetation in natural potential plant • Regulating irrigation water helps to control community: Thurber needlegrass, Wyoming runoff and erosion. big sagebrush Interpretive Groups General management considerations: • Forage production is limited by low Land capability classification: IIIe, irrigated, and precipitation. VIe, nonirrigated • Seeding is limited by low precipitation and the Range site: Loamy, 8 to 10 inch precipitation moderate hazard of water erosion. zone • Seeding generally is most successful late in fall; however, it may not be successful in years 95—Purdam silt loam, 8 to 12 percent when precipitation is below average during the slopes growing season. Interpretive Groups Composition Land capability classification: VIe, nonirrigated Purdam soil and similar inclusions—85 percent Range site: Loamy, 8 to 10 inch precipitation Contrasting inclusions—15 percent zone Setting Position on landscape: Sides of terraces 96—Quincy loamy fine sand, 2 to 20 Elevation: 3,500 to 4,000 feet percent slopes Average annual precipitation: 8 to 10 inches Average annual air temperature: 47 to 51 Composition degrees F Quincy soil and similar inclusions—85 percent Frost-free season: 120 to 140 days Contrasting inclusions—15 percent Characteristics of the Purdam Soil Setting Typical profile: Position on landscape: Sides of terraces 0 to 3 inches—light brownish gray silt loam Elevation: 3,000 to 3,500 feet 3 to 10 inches—pale brown silt loam Average annual precipitation: 8 to 10 inches 10 to 16 inches—light brownish gray silt Average annual air temperature: 47 to 49 loam degrees F 16 to 32 inches—very pale brown silt loam Frost-free season: 130 to 140 days 32 to 60 inches—white lime- and silica- cemented hardpan over light yellowish Characteristics of the Quincy Soil brown gravelly loam Depth class: Moderately deep to a hardpan Typical profile: Drainage class: Well drained 0 to 5 inches—pale brown loamy fine sand Permeability: Moderately slow 5 to 54 inches—pale brown loamy fine sand Available water capacity: 4.5 to 7.5 inches 54 to 70 inches—light gray stratified silt loam Potential rooting depth: 20 to 40 inches and fine sandy loam Runoff: Medium Depth class: Very deep Hazard of water erosion: Moderate Drainage class: Excessively drained Shrink-swell potential: Moderate Permeability: Rapid Available water capacity: 6 to 7 inches Contrasting Inclusions Potential rooting depth: 60 inches or more Bahem soils on the sides of terraces; Power soils Runoff: Slow on terraces Hazard of water erosion: Slight 96 Soil Survey

Hazard of wind erosion: Severe Permeability: Rapid Effervescence: Slight or strong in the surface Available water capacity: 6.5 to 7.5 inches layer Potential rooting depth: 60 inches or more Runoff: Slow Contrasting Inclusions Hazard of water erosion: Slight Kudlac soils on the sides of terraces, Lankbush Hazard of wind erosion: Severe and Rad soils on lower lying terraces; areas of blowout Characteristics of the Kecko Soil Use and Management Typical profile: 0 to 10 inches—pale brown loamy fine sand Major use: Rangeland 10 to 18 inches—pale brown fine sandy loam Major management factors: Precipitation, hazard 18 to 60 inches—light brownish gray fine of wind erosion sandy loam Dominant vegetation in natural potential plant Depth class: Very deep community: Indian ricegrass, Drainage class: Well drained needleandthread, basin big sagebrush Permeability: Moderately rapid General management considerations: Available water capacity: 7.5 to 8.5 inches • Forage production is limited by precipitation. Potential rooting depth: 60 inches or more • Seeding is limited by low precipitation and the Runoff: Slow severe hazard of wind erosion. Hazard of water erosion: Slight Interpretive Groups Hazard of wind erosion: Severe Land capability classification: VIIe, nonirrigated Contrasting Inclusions Range site: Sand, 8 to 12 inch precipitation zone Fathom, Jestrick, and Taunton soils on higher lying terraces; soils that are deep to bedrock, 97—Quincy-Kecko complex, 1 to 6 are loamy fine sand over fine sandy loam, percent slopes and are on lower lying terraces; areas of Rock outcrop Composition Use and Management Quincy soil and similar inclusions—45 percent Major uses: Irrigated cropland, rangeland Kecko soil and similar inclusions—40 percent Major management factors: Precipitation, hazard Contrasting inclusions—15 percent of wind erosion Setting Irrigated Cropland Position on landscape: Terraces General management considerations: Elevation: 3,500 to 4,000 feet • Most climatically suited crops can be grown if Average annual precipitation: 8 to 11 inches irrigation water is provided. Average annual air temperature: 48 to 50 • Sprinkler irrigation is suited to this soil. degrees F • Production of irrigated crops is limited by the Frost-free season: 130 to 140 days severe hazard of wind erosion. • The risk of wind erosion is reduced by Characteristics of the Quincy Soil maintaining crop residue on the surface, keeping Typical profile: tillage at a minimum, and keeping the surface of 0 to 10 inches—light brownish gray loamy the soil rough. fine sand Rangeland 10 to 42 inches—light gray loamy fine sand 42 to 53 inches—very pale brown fine sandy Dominant vegetation in natural potential plant loam community: Indian ricegrass, 53 to 70 inches—very pale brown silt loam needleandthread, basin big sagebrush Depth class: Very deep General management considerations: Drainage class: Excessively drained • Forage production is limited by low Jerome-Twin Falls, Idaho 97

precipitation. • Most climatically suited crops can be grown if • Seeding is limited by low precipitation and the irrigation water is provided. severe hazard of wind erosion. • Surface and sprinkler irrigation systems are • Seeding generally is most successful late in suited to this soil. fall; however, it may not be successful in years • Because of the slow permeability, the when precipitation is below average during the application of irrigation water should be adjusted growing season. to the water intake rate. • Seeding burned or disturbed areas helps to • Roots are restricted below a depth of 15 to 30 control blowing and drifting sand. inches because of the weak silica cementation. • Deep chiseling or ripping improves the rooting Interpretive Groups depth. Land capability classification: IIIe, irrigated, and Interpretive Groups VIe, nonirrigated Range site: Sand, 8 to 12 inch precipitation zone Land capability classification: IIc, irrigated, and VIc, nonirrigated 98—Rad silt loam, 0 to 2 percent slopes 99—Rad silt loam, 2 to 4 percent Composition slopes Rad soil and similar inclusions—90 percent Composition Contrasting inclusions—10 percent Rad soil and similar inclusions—90 percent Setting Contrasting inclusions—10 percent Position on landscape: Terraces Setting Elevation: 3,200 to 4,500 feet Average annual precipitation: 8 to 11 inches Position on landscape: Terraces Average annual air temperature: 48 to 50 Elevation: 3,500 to 4,500 feet degrees F Average annual precipitation: 9 to 11 inches Frost-free season: 110 to 140 days Average annual air temperature: 48 to 50 degrees F Characteristics of the Rad Soil Frost-free season: 110 to 140 days Typical profile: 0 to 6 inches—pale brown silt loam Characteristics of the Rad Soil 6 to 17 inches—pale brown and very pale brown silt loam Typical profile: 17 to 60 inches—very pale brown silt loam 0 to 8 inches—brown silt loam Depth class: Very deep 8 to 22 inches—pale brown silt loam Drainage class: Well drained 22 to 45 inches—light gray silt loam Permeability: Slow 45 to 60 inches—pale brown silt loam Available water capacity: 10 to 11 inches Depth class: Very deep Potential rooting depth: 60 inches or more Drainage class: Well drained Runoff: Slow Permeability: Slow Hazard of water erosion: Slight Available water capacity: 10 to 11 inches Potential rooting depth: 60 inches or more Contrasting Inclusions Runoff: Slow Bahem and Sluka soils on terraces Hazard of water erosion: Slight Use and Management Contrasting Inclusions Major use: Irrigated cropland Major management factors: Permeability, weak Bahem, Portneuf, and Shano soils on terraces, cementation Power and Sluka soils on lower lying General management considerations: terraces, areas of Rock outcrop 98 Soil Survey

Use and Management Average annual air temperature: 48 to 50 degrees F Major uses: Irrigated cropland, rangeland Frost-free season: 110 to 140 days Major management factors: Precipitation, permeability, weak cementation Characteristics of the Rad Soil Irrigated Cropland Typical profile: 0 to 4 inches—pale brown silt loam General management considerations: 4 to 9 inches—brown silt loam • Most climatically suited crops can be grown if 9 to 13 inches—pale brown silt loam irrigation water is provided. 13 to 23 inches—light gray silt loam • Surface and sprinkler irrigation systems are 23 to 47 inches—pale brown very fine sandy suited to this soil. loam • Because of the slow permeability, the 47 to 60 inches—very pale brown very fine application of irrigation water should be adjusted sandy loam to the water intake rate. Depth class: Very deep • Roots are restricted below a depth of 15 to 30 Drainage class: Well drained inches because of the weak silica cementation. Permeability: Slow • Deep chiseling or ripping improves the rooting Available water capacity: 10 to 11 inches depth. Potential rooting depth: 60 inches or more Rangeland Runoff: Medium Hazard of water erosion: Moderate Dominant vegetation in natural potential plant community: Thurber needlegrass, Wyoming Contrasting Inclusions big sagebrush Bahem and Portneuf soils on the sides of General management considerations: terraces; Barrymore soils on higher lying • Forage production and seeding are limited terraces; Sluka soils on lower lying terraces; mainly by low precipitation. areas of Rock outcrop • Seeding generally is most successful late in fall; however, it may not be successful in years Use and Management when precipitation is below average during the Major uses: Irrigated cropland, rangeland growing season. Major management factors: Precipitation, Interpretive Groups permeability, weak cementation, slope, hazard of water erosion Land capability classification: IIe, irrigated, and VIc, nonirrigated Irrigated Cropland Range site: Loamy, 8 to 10 inch precipitation General management considerations: zone • Most climatically suited crops can be grown if irrigation water is provided. 100—Rad silt loam, 4 to 8 percent • Sprinkler irrigation is best suited to this soil, but slopes surface irrigation can be used if the water is regulated to control erosion. • Because of the slow permeability, the Composition application of irrigation water should be adjusted Rad soil and similar inclusions—90 percent to the water intake rate. Contrasting inclusions—10 percent • Roots are restricted below a depth of 15 to 30 inches because of the weak silica cementation. Setting • Deep chiseling or ripping improves the rooting Position on landscape: Sides of terraces depth. Elevation: 3,500 to 4,500 feet • Production of irrigated crops is limited by slope Average annual precipitation: 9 to 11 inches and the moderate hazard of water erosion. Jerome-Twin Falls, Idaho 99

• Regulating irrigation water helps to control Runoff: Medium runoff and erosion. Hazard of water erosion: Moderate Rangeland Contrasting Inclusions Dominant vegetation in natural potential plant Bahem soils on the sides of terraces community: Thurber needlegrass, Wyoming Use and Management big sagebrush General management considerations: Major use: Irrigated cropland • Forage production is limited by low Major management factors: Permeability, weak precipitation. cementation, slope, hazard of water erosion • Seeding is limited by low precipitation and the General management considerations: moderate hazard of water erosion. • Because areas of this soil are long and narrow, • Seeding generally is most successful late in management is dependent on the major uses of fall; however, it may not be successful in years the less sloping, wider surrounding areas. when precipitation is below average during the Interpretive Groups growing season. Land capability classification: IVe, irrigated, and Interpretive Groups VIe, nonirrigated Land capability classification: IIIe, irrigated, and VIe, nonirrigated Range site: Loamy, 8 to 10 inch precipitation 102—Rad silt loam, 12 to 20 percent zone slopes

Composition 101—Rad silt loam, 8 to 12 percent slopes Rad soil and similar inclusions—90 percent Contrasting inclusions—10 percent Composition Setting Rad soil and similar inclusions—90 percent Position on landscape: Sides of terraces Contrasting inclusions—10 percent Elevation: 3,500 to 4,500 feet Average annual precipitation: 9 to 11 inches Setting Average annual air temperature: 48 to 50 Position on landscape: Sides of terraces degrees F Elevation: 4,100 to 4,300 feet Frost-free season: 110 to 140 days Average annual precipitation: 8 to 11 inches Average annual air temperature: 48 to 50 Characteristics of the Rad Soil degrees F Typical profile: Frost-free season: 110 to 120 days 0 to 28 inches—pale brown silt loam Characteristics of the Rad Soil 28 to 44 inches—very pale brown silt loam 44 to 60 inches—light gray very fine sandy Typical profile: loam 0 to 9 inches—brown silt loam Depth class: Very deep 9 to 15 inches—pale brown silt loam Drainage class: Well drained 15 to 21 inches—light brownish gray silt Permeability: Slow loam Available water capacity: 10 to 11 inches 21 to 60 inches—light gray and light Potential rooting depth: 60 inches or more brownish gray silt loam Runoff: Medium Depth class: Very deep Hazard of water erosion: Moderate Drainage class: Well drained Permeability: Slow Contrasting Inclusions Available water capacity: 10 to 11 inches Potential rooting depth: 60 inches or more Bahem soils on the sides of terraces 100 Soil Survey

Use and Management Depth class: Shallow to bedrock Drainage class: Well drained Major use: Rangeland Permeability: Moderately slow Major management factors: Precipitation, hazard Available water capacity: 1.5 to 2.5 inches of water erosion Potential rooting depth: 10 to 20 inches Dominant vegetation in natural potential plant Runoff: Medium community: Thurber needlegrass, Wyoming Hazard of water erosion: Moderate big sagebrush Shrink-swell potential: Moderate General management considerations: • Forage production is limited by low Characteristics of the Flatron Soil precipitation. Typical profile: • Seeding is limited by low precipitation and the 0 to 4 inches—grayish brown very gravelly moderate hazard of water erosion. loam • Seeding generally is most successful late in 4 to 6 inches—brown very cobbly clay loam fall; however, it may not be successful in years 6 to 12 inches—brown extremely gravelly when precipitation is below average during the clay growing season. 12 inches—bedrock Interpretive Groups Depth class: Shallow to bedrock Drainage class: Well drained Land capability classification: VIe, nonirrigated Permeability: Slow Range site: Loamy, 8 to 10 inch precipitation Available water capacity: 1 inch to 2 inches zone Potential rooting depth: 10 to 20 inches Runoff: Medium 103—Ragpie-Flatron complex, 2 to 20 Hazard of water erosion: Moderate percent slopes Shrink-swell potential: Moderate Contrasting Inclusions Composition Mackey and Ruclick soils on dip slopes; soils that Ragpie soil and similar inclusions—60 percent are shallow to bedrock, are gravelly loam Flatron soil and similar inclusions—30 percent over gravelly clay, and are on ridges; areas Contrasting inclusions—10 percent of Rock outcrop Setting Use and Management Position on landscape: Ragpie soil—convex Major use: Rangeland areas of ridges and dip slopes; Flatron soil— Major management factors: Depth to bedrock, concave and plane areas of ridges and dip available water capacity, hazard of water slopes erosion Elevation: 5,000 to 5,700 feet Dominant vegetation in natural potential plant Average annual precipitation: 14 to 16 inches community: Bluebunch wheatgrass,Wyoming Average annual air temperature: 45 to 48 big sagebrush degrees F General management considerations: Frost-free season: 100 to 110 days • Forage production is limited by the shallow rooting depth and low available water capacity. Characteristics of the Ragpie Soil • Seeding is limited by the moderate hazard of Typical profile: water erosion. 0 to 3 inches—brown very gravelly loam Interpretive Groups 3 to 9 inches—brown gravelly clay loam 9 to 16 inches—pale brown very gravelly Land capability classification: VIIs, nonirrigated clay loam Range site: Shallow stony, 12 to 16 inch 16 inches—bedrock precipitation zone Jerome-Twin Falls, Idaho 101

104—Rakane-Blacknest complex, 1 to Hazard of water erosion: Slight 4 percent slopes Shrink-swell potential: Moderate Contrasting Inclusions Composition Bahem and Sluka soils on lower lying terraces; Rakane soil and similar inclusions—45 percent Chuska soils on higher lying terraces; soils Blacknest soil and similar inclusions—35 percent that are deep to sand and gravel, are loam Contrasting inclusions—20 percent over sandy clay loam over sandy loam, and are on terraces Setting Use and Management Position on landscape: Terraces Elevation: 3,000 to 4,000 feet Major uses: Rangeland, irrigated cropland Average annual precipitation: 8 to 10 inches Major management factors: Permeability, Average annual air temperature: 47 to 49 precipitation degrees F Rangeland Frost-free season: 120 to 140 days Dominant vegetation in natural potential plant Characteristics of the Rakane Soil community: Thurber needlegrass, Wyoming Typical profile: big sagebrush 0 to 3 inches—brown loam General management considerations: 3 to 9 inches—pale brown loam • Forage production and seeding are limited 9 to 25 inches—light yellowish brown clay mainly by low precipitation. loam • Seeding generally is most successful late in 25 to 38 inches—very pale brown gravelly fall; however, it may not be successful in years loam when precipitation is below average during the 38 to 73 inches—lime- and silica-cemented growing season. hardpan Irrigated Cropland Depth class: Moderately deep to a hardpan Drainage class: Well drained General management considerations: Permeability: Moderately slow • Most climatically suited crops can be grown if Available water capacity: 3.5 to 6.5 inches irrigation water is provided. Potential rooting depth: 20 to 40 inches • Surface and sprinkler irrigation systems are Runoff: Slow suited to this unit. Hazard of water erosion: Slight • Because of the moderately slow permeability, Shrink-swell potential: Moderate the application of irrigation water should be adjusted to the water intake rate. Characteristics of the Blacknest Soil Typical profile: Interpretive Groups 0 to 5 inches—pale brown loam Land capability classification: IIIs, irrigated, and 5 to 13 inches—pale brown sandy clay loam VIs, nonirrigated 13 to 24 inches—pale brown gravelly sandy Range site: Loamy, 8 to 10 inch precipitation clay loam zone 24 to 30 inches—very pale brown gravelly sandy loam 30 to 60 inches—multicolored extremely 105—Rakane-Blacknest complex, 4 to gravelly sand 8 percent slopes Depth class: Very deep Drainage class: Well drained Composition Permeability: Moderately slow over very rapid Available water capacity: 5.5 to 6.5 inches Rakane soil and similar inclusions—45 percent Potential rooting depth: 20 to 40 inches Blacknest soil and similar inclusions—35 percent Runoff: Slow Contrasting inclusions—20 percent 102 Soil Survey

Setting Rangeland Position on landscape: Sides of terraces Dominant vegetation in natural potential plant Elevation: 3,000 to 4,000 feet community: Thurber needlegrass, Wyoming Average annual precipitation: 8 to 10 inches big sagebrush Average annual air temperature: 47 to 49 General management considerations: degrees F • Forage production is limited by low Frost-free season: 120 to 140 days precipitation. • Seeding is limited by low precipitation and the Characteristics of the Rakane Soil moderate hazard of water erosion. Typical profile: • Seeding generally is most successful late in 0 to 6 inches—light brownish gray loam fall; however, it may not be successful in years 6 to 16 inches—pale brown sandy clay loam when precipitation is below average during the 16 to 24 inches—pale brown clay loam growing season. 24 to 41 inches—lime- and silica-cemented Irrigated Cropland hardpan Depth class: Moderately deep to a hardpan General management considerations: Drainage class: Well drained • Most climatically suited crops can be grown if Permeability: Moderately slow irrigation water is provided. Available water capacity: 3.5 to 6.5 inches • Sprinkler irrigation is best suited to the soils in Potential rooting depth: 20 to 40 inches this unit, but surface irrigation can be used if the Runoff: Medium water is regulated to control erosion. Hazard of water erosion: Moderate • Because of the moderately slow permeability, Shrink-swell potential: Moderate the application of irrigation water should be adjusted to the water intake rate. Characteristics of the Blacknest Soil • Production of irrigated crops is limited by slope Typical profile: and the moderate hazard of water erosion. 0 to 13 inches—pale brown loam • Regulating irrigation water helps to control 13 to 24 inches—pale brown gravelly clay runoff and erosion. loam Interpretive Groups 24 to 31 inches—very pale brown gravelly sandy loam Land capability classification: IIIe, irrigated, and 31 to 60 inches—multicolored extremely VIe, nonirrigated gravelly sand Range site: Loamy, 8 to 10 inch precipitation Depth class: Very deep zone Drainage class: Well drained Permeability: Moderately slow over very rapid Available water capacity: 5.5 to 6.5 inches 106—Rakane-Blacknest complex, 8 to Potential rooting depth: 20 to 40 inches 15 percent slopes Runoff: Medium Hazard of water erosion: Moderate Composition Shrink-swell potential: Moderate Rakane soil and similar inclusions—40 percent Contrasting Inclusions Blacknest soil and similar inclusions—35 percent Chuska soils on higher lying terraces; Sluka soils Contrasting inclusions—25 percent on lower lying terraces; soils that are deep to sand and gravel, are loam over sandy clay Setting loam over gravelly loam, and are on the sides of terraces Position on landscape: Sides of terraces Elevation: 3,000 to 4,000 feet Use and Management Average annual precipitation: 8 to 10 inches Major uses: Rangeland, irrigated cropland Average annual air temperature: 47 to 49 Major management factors: Precipitation, degrees F permeability, slope, hazard of water erosion Frost-free season: 120 to 140 days Jerome-Twin Falls, Idaho 103

Characteristics of the Rakane Soil • Forage production is limited by low precipitation. Typical profile: • Seeding is limited by low precipitation and the 0 to 5 inches—light brownish gray loam moderate hazard of water erosion. 5 to 20 inches—pale brown loam • Seeding generally is most successful late in 20 to 29 inches—pale brown sandy clay fall; however, it may not be successful in years loam when precipitation is below average during the 29 to 39 inches—very pale brown loam growing season. 39 to 62 inches—lime- and silica-cemented hardpan Irrigated Cropland Depth class: Moderately deep to a hardpan General management consideration: Drainage class: Well drained • Because areas of this unit are long and narrow, Permeability: Moderately slow management is dependent on the major uses of Available water capacity: 3.5 to 6.5 inches the adjacent areas that are less sloping and Potential rooting depth: 20 to 40 inches wider. Runoff: Medium Hazard of water erosion: Moderate Interpretive Groups Shrink-swell potential: Moderate Land capability classification: IVe, irrigated, and Characteristics of the Blacknest Soil VIe, nonirrigated Range site: Loamy, 8 to 10 inch precipitation Typical profile: zone 0 to 5 inches—light brownish gray loam 5 to 20 inches—pale brown sandy clay loam 20 to 30 inches—very pale brown gravelly 107—Rock outcrop-Banbury-Paulville sandy loam complex, 2 to 6 percent slopes 30 to 60 inches—multicolored extremely gravelly sand Composition Depth class: Very deep Drainage class: Well drained Rock outcrop—40 percent Permeability: Moderately slow over very rapid Banbury soil and similar inclusions—30 percent Available water capacity: 5.5 to 6.5 inches Paulville soil and similar inclusions—15 percent Potential rooting depth: 20 to 40 inches Contrasting inclusions—15 percent Runoff: Medium Setting Hazard of water erosion: Moderate Shrink-swell potential: Moderate Position on landscape: Banbury soil—plane to convex areas of terraces, Paulville soil— Contrasting Inclusions concave areas of terraces Very deep gravelly silt loam on the sides of Elevation: 3,500 to 4,500 feet terraces; soils that are deep to sand and Average annual precipitation: 9 to 10 inches gravel, are loam over sandy clay loam over Average annual air temperature: 49 to 51 gravelly sandy loam, and are on the sides of degrees F terraces Frost-free season: 120 to 140 days Use and Management Characteristics of the Rock Outcrop Major uses: Rangeland, irrigated cropland Kind of rock: Exposed basalt Major management factors: Precipitation, Description of areas: Sharp, angular to permeability, slope, hazard of water erosion semirounded, long, narrow ridges ranging to semirounded outcroppings that extend 1 foot Rangeland to 10 feet above the adjacent landscape Dominant vegetation in natural potential plant Characteristics of the Banbury Soil community: Thurber needlegrass, Wyoming big sagebrush Typical profile: General management considerations: 0 to 5 inches—brown loam 104 Soil Survey

5 to 9 inches—pale brown loam Interpretive Groups 9 to 15 inches—pale brown clay loam Land capability classification: VIIs, nonirrigated 15 inches—bedrock Range site: Banbury soil—Shallow loamy, 8 to 12 Depth class: Shallow to bedrock inch precipitation zone; Paulville soil— Drainage class: Well drained Loamy, 8 to 12 inch precipitation zone Permeability: Moderate Available water capacity: 2.0 to 3.5 inches Potential rooting depth: 10 to 20 inches 108—Rock outcrop-Xerorthents Runoff: Slow complex, very steep Hazard of water erosion: Slight Shrink-swell potential: Moderate Composition Characteristics of the Paulville Soil Rock outcrop—50 percent Typical profile: Xerorthents and similar inclusions—40 percent 0 to 8 inches—pale brown loam Contrasting inclusions—10 percent 8 to 47 inches—pale brown clay loam Setting 47 to 60 inches—light gray gravelly loam Depth class: Very deep Position on landscape: Breaks Drainage class: Well drained Elevation: 2,800 to 6,000 feet Permeability: Moderately slow Average annual precipitation: 8 to 15 inches Available water capacity: 9 to 12 inches Average annual air temperature: 44 to 52 Potential rooting depth: 60 inches or more degrees F Runoff: Slow Frost-free season: 90 to 140 days Hazard of water erosion: Slight Characteristics of the Rock Outcrop Shrink-swell potential: Moderate Kind of rock: Exposed welded tuff or basalt Contrasting Inclusions Description of areas: Very steep to perpendicular Emberton, Kecko, and Quincy soils on lower cliffs and rimrock that border lower lying lying terraces; McCain, Sidlake, and Suepert valley terraces and talus material that soils in plane to convex areas of terraces; separated from the rimrock and was Owinza soils in depressional areas of randomly deposited downslope terraces Characteristics of the Xerorthents Use and Management Slope range: 40 to 75 percent Major use: Rangeland Example profile: Major management factors: Precipitation, 0 to 6 inches—pale brown stony loam available water capacity, depth to bedrock, 6 to 60 inches—very pale brown loam areas of Rock outcrop Depth class: Shallow to very deep Dominant vegetation in natural potential plant Drainage class: Well drained or somewhat community: Banbury and Paulville soils— excessively drained bluebunch wheatgrass, Wyoming big Permeability: Moderately slow to moderately sagebrush rapid General management considerations: Available water capacity: 7 to 11 inches • Forage production is limited by the low Potential rooting depth: 60 inches or more precipitation and shallow rooting depth of the Runoff: Rapid Banbury and Paulville soils and by the low Hazard of water erosion: Severe available water capacity of the Banbury soil. Contrasting Inclusions • Seeding is limited by low precipitation and the areas of Rock outcrop. Antelope Springs soils on alluvial fans; Gosinta • The use of equipment is limited by the areas of soils on alluvial terraces; Kudlac soils on Rock outcrop. breaks; very deep very stony loam on Jerome-Twin Falls, Idaho 105

breaks; very deep, poorly drained soils that 18 to 27 inches—light yellowish brown sandy are silt loam over silty clay loam and are in loam depressional areas of alluvial terraces 27 to 45 inches—white fractured lime- and silica-cemented hardpan Use and Management Depth class: Shallow to a hardpan Major use: Rangeland Drainage class: Well drained Major management factors: Precipitation, slope, Permeability: Moderately slow hazard of water erosion, areas of Rock Available water capacity: 2 to 4 inches outcrop Potential rooting depth: 10 to 20 inches Dominant vegetation in natural potential plant Runoff: Medium community: Xerorthents—bluebunch Hazard of water erosion: Moderate wheatgrass, Thurber needlegrass, Wyoming Shrink-swell potential: Moderate big sagebrush Contrasting Inclusions General management considerations: • Forage production is limited by low Chuska and Colthorp soils on higher lying precipitation. terraces; Elijah soils on terraces; Shabliss • The use of forage by livestock is limited by and Yahoo soils on lower lying terraces; soils slope. that are deep to a hardpan, are silt loam over • Seeding is limited by the severe hazard of silty clay loam over silt loam, and are on water erosion, slope, and the areas of Rock lower lying terraces; soils that are shallow to outcrop. a hardpan, are slightly saline, and are on lower lying terraces; barren areas that are 10 Interpretive Groups to 20 feet in diameter and are saline, are Land capability classification: VIII, nonirrigated shallow and clayey, or are subject to ant Range site: Because of the variability of the activity Xerorthents, onsite evaluation is needed to Use and Management determine the range site in specific areas. Major uses: Irrigated cropland, rangeland Major management factors: Precipitation, 109—Roseworth silt loam, 1 to 8 available water capacity, depth to the percent slopes hardpan, permeability, hazard of water erosion Composition Irrigated Cropland Roseworth soil and similar inclusions—80 percent General management considerations: Contrasting inclusions—20 percent • Most climatically suited crops can be grown if irrigation water is provided. Setting • Sprinkler irrigation is best suited to this soil, but Position on landscape: Terraces surface irrigation can be used if the water is Elevation: 4,000 to 4,600 feet regulated to control erosion. Average annual precipitation: 8 to 10 inches • Because of the moderately slow permeability, Average annual air temperature: 47 to 49 the application of irrigation water should be degrees F adjusted to the water intake rate. Frost-free season: 100 to 120 days • Production of irrigated crops is limited by the shallow rooting depth, low available water Characteristics of the Roseworth Soil capacity, and moderate hazard of water erosion. Typical profile: Rangeland 0 to 3 inches—pale brown silt loam 3 to 8 inches—pale brown silty clay loam Dominant vegetation in natural potential plant 8 to 15 inches—very pale brown silt loam community: Thurber needlegrass, Wyoming 15 to 18 inches—white lime- and silica- big sagebrush cemented hardpan General management considerations: 106 Soil Survey

• Forage production is limited by low Hazard of water erosion: Moderate precipitation, shallow rooting depth, and low Shrink-swell potential: Moderate available water capacity. Contrasting Inclusions • Seeding is limited by low precipitation and the moderate hazard of water erosion. Elijah soils on mounds • Seeding generally is most successful late in Use and Management fall; however, it may not be successful in years when precipitation is below average during the Major use: Rangeland growing season. Major management factors: Precipitation, depth to the hardpan, available water capacity, Interpretive Groups hazard of water erosion Land capability classification: IVe, irrigated, and Dominant vegetation in natural potential plant VIe, nonirrigated community: Thurber needlegrass, Wyoming Range site: Loamy, 8 to 10 inch precipitation big sagebrush zone General management considerations: • Forage production is limited by low precipitation, shallow rooting depth, and low 110—Roseworth cobbly silt loam, 1 to available water capacity. 8 percent slopes • Seeding is limited by low precipitation and the moderate hazard of water erosion. Composition • Seeding generally is most successful late in fall; however, it may not be successful in years Roseworth soil and similar inclusions—90 when precipitation is below average during the percent growing season. Contrasting inclusions—10 percent Interpretive Groups Setting Land capability classification: VIs, nonirrigated Position on landscape: Terraces Range site: Loamy, 8 to 10 inch precipitation Elevation: 4,000 to 4,600 feet zone Average annual precipitation: 8 to 10 inches Average annual air temperature: 47 to 49 degrees F 111—Roza loam, 0 to 1 percent Frost-free season: 100 to 120 days slopes Characteristics of the Roseworth Soil Composition Typical profile: 0 to 3 inches—pale brown cobbly silt loam Roza soil and similar inclusions—90 percent 3 to 8 inches—pale brown silty clay loam Contrasting inclusions—10 percent 8 to 15 inches—very pale brown gravelly Setting loam 15 to 18 inches—white lime- and silica- Position on landscape: Playas cemented hardpan Elevation: 4,500 to 4,600 feet 18 to 27 inches—very pale brown gravelly Average annual precipitation: 8 to 10 inches fine sandy loam Average annual air temperature: 49 to 50 27 inches—fractured white lime- and silica- degrees F cemented hardpan Frost-free season: 110 to 120 days Depth class: Shallow to a hardpan Characteristics of the Roza Soil Drainage class: Well drained Permeability: Moderately slow Typical profile: Available water capacity: 2 to 4 inches 0 to 1 inch—light gray loam Potential rooting depth: 10 to 20 inches 1 inch to 4 inches—light gray clay loam Runoff: Medium 4 to 18 inches—light brownish gray clay Jerome-Twin Falls, Idaho 107

18 to 30 inches—pale brown clay Characteristics of the Ruclick Soil 30 to 49 inches—pale brown clay loam Typical profile: 49 to 73 inches—very pale brown clay loam 0 to 3 inches—grayish brown very gravelly Depth class: Very deep loam Drainage class: Well drained 3 to 9 inches—brown gravelly clay loam Permeability: Slow 9 to 28 inches—brown extremely gravelly Available water capacity: 8 to 10 inches clay loam Potential rooting depth: 60 inches or more 28 inches—bedrock Runoff: Ponded Depth class: Moderately deep to bedrock Hazard of water erosion: Slight Drainage class: Well drained Shrink-swell potential: High Permeability: Slow Contrasting Inclusions Available water capacity: 2.5 to 4.5 inches Potential rooting depth: 20 to 40 inches Very deep soils that are cobbly loam over clay Runoff: Medium loam over loam and are on playas Hazard of water erosion: Moderate Use and Management Contrasting Inclusions Major use: Rangeland Chuska and Oshone soils on lower lying Major management factors: Precipitation terraces; Flatron and Ragpie soils on ridges; Dominant vegetation in natural potential plant Nawt soils on breaks; soils that are community: Bluebunch wheatgrass, moderately deep to bedrock, are very Wyoming big sagebrush gravelly loam over gravelly loam, amd are on General management considerations: dip slopes; areas of Rock outcrop; barren • Forage production and seeding are limited areas that are 10 to 20 feet in diameter and mainly by low precipitation. are saline, are shallow and clayey, or are • Seeding generally is most successful late in subject to ant activity fall; however, it may not be successful in years when precipitation is below average during the Use and Management growing season. Major use: Rangeland Interpretive Groups Major management factors: Precipitation, rock fragments in the surface layer, hazard of Land capability classification: VIs, nonirrigated water erosion Range site: Loamy, 8 to 12 inch precipitation Dominant vegetation in natural potential plant zone community: Bluebunch wheatgrass, Wyoming big sagebrush 112—Ruclick very gravelly loam, 5 to General management considerations: 30 percent slopes • Forage production is limited by low precipitation. • Seeding is limited by low precipitation, the rock Composition fragments in the surface layer, and the moderate Ruclick soil and similar inclusions—85 percent hazard of water erosion Contrasting inclusions—15 percent • Seeding generally is most successful late in fall; however, it may not be successful in years Setting when precipitation is below average during the Position on landscape: Dip slopes growing season. Elevation: 5,100 to 6,000 feet Interpretive Groups Average annual precipitation: 12 to 14 inches Average annual air temperature: 47 to 49 Land capability classification: VIe, nonirrigated degrees F Range site: Stony loam, 12 to 16 inch Frost-free season: 100 to 110 days precipitation zone 108 Soil Survey

113—Rutherford extremely gravelly • Forage production is limited by the short loam, 2 to 20 percent slopes growing season and low available water capacity. • Seeding is limited by the rock fragments in the surface layer and the moderate hazard of water Composition erosion. Rutherford soil and similar inclusions—80 Interpretive Groups percent Contrasting inclusions—20 percent Land capability classification: VIs, nonirrigated Range site: Mountain ridge, 14 to 18 inch Setting precipitation zone Position on landscape: Ridges and dip slopes Elevation: 6,500 to 7,700 feet Average annual precipitation: 15 to 20 inches 114—Schnipper silt loam, 2 to 6 Average annual air temperature: 37 to 43 percent slopes degrees F Frost-free season: 20 to 60 days Composition Characteristics of the Rutherford Soil Schnipper soil and similar inclusions—90 percent Typical profile: Contrasting inclusions—10 percent 0 to 4 inches—grayish brown extremely gravelly loam Setting 4 to 10 inches—brown very gravelly clay Position on landscape: Terraces loam Elevation: 5,000 to 5,500 feet 10 to 19 inches—yellowish brown very Average annual precipitation: 10 to 14 inches gravelly clay loam Average annual air temperature: 45 to 48 19 to 26 inches—brown extremely gravelly degrees F clay loam Frost-free season: 100 to 110 days 26 inches—bedrock Depth class: Moderately deep to bedrock Characteristics of the Schnipper Soil Drainage class: Well drained Typical profile: Permeability: Slow 0 to 4 inches—grayish brown silt loam Available water capacity: 1.5 to 3.0 inches 4 to 8 inches—brown silt loam Potential rooting depth: 20 to 40 inches 8 to 30 inches—brown and pale brown clay Runoff: Medium loam Hazard of water erosion: Moderate 30 to 37 inches—very pale brown loam Contrasting Inclusions 37 to 40 inches—white hardpan over very pale brown gravelly loam Hogmalat and Keman soils on summits; soils that 40 to 60 inches—yellowish brown gravelly are shallow to bedrock, are very gravelly clay loam clay, and are on ridges; soils that are deep to Depth class: Moderately deep to a hardpan bedrock, are gravelly loam over gravelly clay Drainage class: Well drained loam, and are on ridges; areas of Rock Permeability: Moderately slow outcrop Available water capacity: 4 to 7 inches Use and Management Potential rooting depth: 20 to 40 inches Runoff: Slow Major use: Rangeland Hazard of water erosion: Slight Major management factors: Growing season, Shrink-swell potential: Moderate available water capacity, rock fragments in the surface layer, hazard of water erosion Contrasting Inclusions Dominant vegetation in natural potential plant community: Idaho fescue, low sagebrush Chuska soils on ridges; Rogerson soils on General management considerations: terraces; soils that are deep to a hardpan, Jerome-Twin Falls, Idaho 109

are silt loam over clay loam over loam, and Contrasting Inclusions are on terraces Chuska soils on ridges; Rogerson soils on Use and Management terraces; soils that are deep to a hardpan, are silt loam over silty clay loam over loam, Major use: Nonirrigated cropland and are on terraces Major management factor: Precipitation General management considerations: Use and Management • Continuous cropping is not suited to this soil Major use: Nonirrigated cropland because of the limited precipitation and lack of Major management factors: Precipitation, slope, irrigation water. hazard of water erosion • A suitable cropping system includes small General management considerations: grain and summer fallow. • Continuous cropping is not suited to this soil Interpretive Groups because of the limited precipitation and lack of irrigation water. Land capability classification: IVs, nonirrigated • A suitable cropping system includes small grain and summer fallow. 115—Schnipper silt loam, 6 to 12 • Production of crops is limited by slope. percent slopes • Farming on the contour reduces the risk of water erosion. Composition Interpretive Groups Schnipper soil and similar inclusions—90 Land capability classification: IVe, nonirrigated percent Contrasting inclusions—10 percent 116—Schnipper-Rogerson complex, 2 Setting to 12 percent slopes Position on landscape: Sides of terraces Elevation: 5,000 to 5,500 feet Composition Average annual precipitation: 10 to 14 inches Schnipper soil and similar inclusions—65 Average annual air temperature: 45 to 48 percent degrees F Rogerson soil and similar inclusions—25 percent Frost-free season: 100 to 110 days Contrasting inclusions—10 percent Characteristics of the Schnipper Soil Setting Typical profile: Position on landscape: Schnipper soil—convex to 0 to 11 inches—brown silt loam plane areas of terraces; Rogerson soil— 11 to 22 inches—brown silty clay loam concave areas of terraces 22 to 36 inches—pale brown loam Elevation: 5,000 to 5,500 feet 36 to 39 inches—white lime- and silica- Average annual precipitation: 10 to 14 inches cemented hardpan over very pale brown Average annual air temperature: 45 to 48 gravelly loam degrees F 39 to 60 inches—light yellowish brown Frost-free season: 100 to 110 days gravelly clay loam Depth class: Moderately deep to a hardpan Characteristics of the Schnipper Soil Drainage class: Well drained Permeability: Moderately slow Slope range: 2 to 12 percent Available water capacity: 4 to 7 inches Typical profile: Potential rooting depth: 20 to 40 inches 0 to 7 inches—brown silt loam Runoff: Medium 7 to 15 inches—brown silty clay loam Hazard of water erosion: Moderate 15 to 30 inches—very pale brown silty clay Shrink-swell potential: Moderate loam 110 Soil Survey

30 to 39 inches—thin lime- and silica- erosion; Schnipper soils—precipitation, cemented hardpan over very pale brown hazard of water erosion gravelly silt loam Dominant vegetation in natural potential plant 39 to 66 inches—light yellowish brown community: Bluebunch wheatgrass, gravelly clay loam Wyoming big sagebrush Depth class: Moderately deep to a hardpan General management considerations: Drainage class: Well drained • Forage production is limited by low Permeability: Moderately slow precipitation and by the low available water Available water capacity: 4 to 7 inches capacity and shallow rooting depth of the Potential rooting depth: 20 to 40 inches Rogerson soil. Runoff: Medium • Seeding is limited by the low precipitation and Hazard of water erosion: Moderate moderate hazard of water erosion. Shrink-swell potential: Moderate • Seeding generally is most successful late in fall; however, it may not be successful in years Characteristics of the Rogerson Soil when precipitation is below average during the Slope range: 2 to 6 percent growing season. Typical profile: Interpretive Groups 0 to 4 inches—pale brown silt loam 4 to 15 inches—brown and pale brown silty Land capability classification: VIe, nonirrigated clay Range site: Loamy, 10 to 13 inch precipitation 15 to 21 inches—very pale brown silty clay zone loam that is weakly cemented or moderately cemented in the upper part 21 to 44 inches—very pale brown silt loam 117—Scoon fine sandy loam, 1 to 4 44 to 62 inches—very pale brown gravelly percent slopes sandy loam Depth class: Shallow to a hardpan Composition Drainage class: Well drained Scoon soil and similar inclusions—90 percent Permeability: Slow Contrasting inclusions—10 percent Available water capacity: 2.5 to 3.5 inches Potential rooting depth: 10 to 20 inches Setting Runoff: Medium Position on landscape: Terraces Hazard of water erosion: Moderate Elevation: 3,350 to 3,500 feet Shrink-swell potential: Moderate Average annual precipitation: 8 to 10 inches Contrasting Inclusions Average annual air temperature: 49 to 51 degrees F Nawt and Stricker soils on breaks; Pigtail soils in Frost-free season: 130 to 140 days depressional areas of terraces; soils that are deep to a hardpan, are silty clay loam over Characteristics of the Scoon Soil silty clay, and are on terraces; soils that are Typical profile: deep to a hardpan, are silt loam over silty 0 to 4 inches—light brownish gray fine sandy clay loam over silt loam, and are on terraces; loam barren areas that are 10 to 20 feet in 4 to 13 inches—light brownish gray loam diameter and are saline, are shallow and 13 to 43 inches—white lime- and silica- clayey, or are subject to ant activity cemented hardpan Depth class: Shallow to a hardpan Use and Management Drainage class: Well drained Major use: Rangeland Permeability: Moderate Major management factors: Rogerson soil— Available water capacity: 1.5 to 3.0 inches depth to the hardpan, available water Potential rooting depth: 8 to 20 inches capacity, precipitation, hazard of water Runoff: Slow Jerome-Twin Falls, Idaho 111

Hazard of water erosion: Slight Setting Hazard of wind erosion: Moderate Position on landscape: Terraces Contrasting Inclusions Elevation: 3,500 to 4,500 feet Average annual precipitation: 8 to 10 inches Bahem and Taunton soils on terraces, Blacknest Average annual air temperature: 49 to 50 and Rakane soils on lower lying terraces degrees F Use and Management Frost-free season: 120 to 140 days Major uses: Rangeland, irrigated cropland Characteristics of the Scoon Soil Major management factors: Precipitation, depth Typical profile: to the hardpan, available water capacity, 0 to 5 inches—light brownish gray loam hazard of wind erosion 5 to 13 inches—light brownish gray loam Rangeland 13 to 15 inches—light gray loam 15 to 40 inches—white lime- and silica- Dominant vegetation in natural potential plant cemented hardpan community: Bluebunch wheatgrass, Depth class: Shallow to a hardpan Wyoming big sagebrush Drainage class: Well drained General management considerations: Permeability: Moderate • Forage production is limited by low Available water capacity: 2 to 4 inches precipitation, shallow rooting depth, and low Potential rooting depth: 8 to 20 inches available water capacity. Runoff: Slow • Seeding is limited by low precipitation and the Hazard of water erosion: Slight moderate hazard of wind erosion. Hazard of wind erosion: Moderate • Seeding generally is most successful late in fall; however, it may not be successful in years Contrasting Inclusions when precipitation is below average during the Taunton soils on terraces growing season. Use and Management Irrigated Cropland Major use: Irrigated cropland General management considerations: Major management factors: Depth to the • Most climatically suited crops can be grown if hardpan, available water capacity, hazard of irrigation water is provided. wind erosion • Surface and sprinkler irrigation systems are General management considerations: suited to this soil. • Most climatically suited crops can be grown if • Production of irrigated crops is limited by the irrigation water is provided. shallow rooting depth, low available water • Surface and sprinkler irrigation systems are capacity, and moderate hazard of wind erosion. suited to this soil. • Production of irrigated crops is limited by the Interpretive Groups shallow rooting depth, low available water Land capability classification: IVs, irrigated, and capacity, and moderate hazard of wind erosion. VIs, nonirrigated Interpretive Groups Range site: Shallow loamy, 8 to 12 inch precipitation zone Land capability classification: IVs, irrigated, and VIs, nonirrigated

118—Scoon loam, 0 to 2 percent 119—Scoon loam, 2 to 4 percent slopes slopes Composition Composition Scoon soil and similar inclusions—90 percent Scoon soil and similar inclusions—90 percent Contrasting inclusions—10 percent Contrasting inclusions—10 percent 112 Soil Survey

Setting irrigation water is provided. • Surface and sprinkler irrigation systems are Position on landscape: Terraces suited to this soil. Elevation: 3,350 to 4,500 feet • Production of irrigated crops is limited by the Average annual precipitation: 8 to 10 inches shallow rooting depth, low available water Average annual air temperature: 49 to 51 capacity, and moderate hazard of wind erosion. degrees F Frost-free season: 120 to 140 days Interpretive Groups Characteristics of the Scoon Soil Land capability classification: IVe, irrigated, and VIe, nonirrigated Typical profile: Range site: Shallow loamy, 8 to 12 inch 0 to 6 inches—pale brown loam precipitation zone 6 to 15 inches—pale brown loam 15 to 19 inches—very pale brown loam 19 to 40 inches—white lime- and silica- 120—Shabliss silt loam, 1 to 4 cemented hardpan percent slopes Depth class: Shallow to a hardpan Drainage class: Well drained Composition Permeability: Moderate Available water capacity: 2 to 4 inches Shabliss soil and similar inclusions—85 percent Potential rooting depth: 8 to 20 inches Contrasting inclusions—15 percent Runoff: Slow Setting Hazard of water erosion: Slight Hazard of wind erosion: Moderate Position on landscape: Terraces Elevation: 4,400 to 4,900 feet Contrasting Inclusions Average annual precipitation: 8 to 10 inches Arbidge soils on lower lying terraces; Roseworth Average annual air temperature: 47 to 49 soils on terraces degrees F Frost-free season: 110 to 120 days Use and Management Characteristics of the Shabliss Soil Major uses: Rangeland, irrigated cropland Major management factors: Precipitation, depth Typical profile: to the hardpan, available water capacity, 0 to 5 inches—brown silt loam hazard of wind erosion 5 to 10 inches—light yellowish brown silt loam Rangeland 10 to 17 inches—very pale brown silt loam Dominant vegetation in natural potential plant 17 to 18 inches—white lime- and silica- community: Bluebunch wheatgrass, cemented hardpan over very pale brown Wyoming big sagebrush silt loam General management considerations: 18 to 31 inches—very pale brown silt loam • Forage production is limited by low 31 to 36 inches—white lime- and silica- precipitation, shallow rooting depth, and low cemented hardpan over very pale brown available water capacity. silt loam • Seeding is limited by low precipitation and the 36 to 68 inches—very pale brown and light moderate hazard of wind erosion. yellowish brown silt loam • Seeding generally is most successful late in Depth class: Shallow to a hardpan fall; however, it may not be successful in years Drainage class: Well drained when precipitation is below average during the Permeability: Moderate growing season. Available water capacity: 2.5 to 3.5 inches Potential rooting depth: 10 to 20 inches Irrigated Cropland Runoff: Slow General management considerations: Hazard of water erosion: Slight • Most climatically suited crops can be grown if Hazard of wind erosion: Moderate Jerome-Twin Falls, Idaho 113

Contrasting Inclusions 121—Shabliss silt loam, 4 to 8 Chiara and Colthorp soils on higher lying percent slopes terraces, Portneuf and Sluka soils on terraces, Power and Rad soils on lower lying Composition terraces Shabliss soil and similar inclusions—85 percent Contrasting inclusions—15 percent Use and Management Setting Major uses: Rangeland, irrigated cropland Major management factors: Precipitation, depth Position on landscape: Terraces to the hardpan, available water capacity, Elevation: 4,400 to 4,900 feet hazard of wind erosion Average annual precipitation: 8 to 10 inches Average annual air temperature: 47 to 49 Rangeland degrees F Frost-free season: 110 to 120 days Dominant vegetation in natural potential plant community: Thurber needlegrass, Wyoming Characteristics of the Shabliss Soil big sagebrush Typical profile: General management considerations: 0 to 3 inches—brown silt loam • Forage production is limited by low 3 to 15 inches—very pale brown silt loam precipitation, shallow rooting depth, and low 15 to 24 inches—white lime- and silica- available water capacity. cemented hardpan over very pale brown • Seeding is limited by low precipitation and the silt loam moderate hazard of wind erosion. 24 to 60 inches—very pale brown silt loam • Seeding generally is most successful late in Depth class: Shallow to a hardpan fall; however, it may not be successful in years Drainage class: Well drained when precipitation is below average during the Permeability: Moderate growing season. Available water capacity: 2.5 to 3.5 inches Potential rooting depth: 10 to 20 inches Irrigated Cropland Runoff: Medium General management considerations: Hazard of water erosion: Moderate • Most climatically suited crops can be grown if Hazard of wind erosion: Moderate irrigation water is provided. Contrasting Inclusions • Surface and sprinkler irrigation systems are suited to this soil. Chiara soils on higher lying terraces, Portneuf • Production is limited by the shallow rooting and Sluka soils on terraces, Power soils on depth, low available water capacity, and lower lying terraces moderate hazard of wind erosion. Use and Management • Roots are restricted below a depth of 12 to 20 inches because of the hardpan. Major uses: Rangeland, irrigated cropland • Deep chiseling or ripping improves the rooting Major management factors: Precipitation, depth depth. to the hardpan, available water capacity, hazard of water erosion, hazard of wind Interpretive Groups erosion Rangeland Land capability classification: IVs, irrigated, and VIs, nonirrigated Dominant vegetation in natural potential plant Range site: Loamy, 8 to 10 inch precipitation community: Thurber needlegrass, Wyoming zone big sagebrush 114 Soil Survey

General management considerations: 10 to 29 inches—light yellowish brown silt • Forage production is limited by the low loam precipitation, shallow rooting depth, and low 29 to 66 inches—pale brown silt loam available water capacity. Depth class: Very deep • Seeding is limited by low precipitation and the Drainage class: Well drained moderate hazards of water and wind erosion. Permeability: Moderate • Seeding generally is most successful late in Available water capacity: 11.0 to 12.5 inches fall; however, it may not be successful in years Potential rooting depth: 60 inches or more when precipitation is below average during the Runoff: Slow growing season. Hazard of water erosion: Slight Irrigated Cropland Contrasting Inclusions General management considerations: Bahem, Barrymore, Portneuf, Rad, and Sluka • Most climatically suited crops can be grown if soils on higher lying terraces; Dolman and irrigation water is provided. Paulville soils on terraces • Sprinkler irrigation is best suited to this soil, but Use and Management surface irrigation can be used if the water is regulated to control erosion. Major use: Irrigated cropland • Production of irrigated crops is limited by the Major management factors: None slope, shallow rooting depth, low available water General management considerations: capacity, and moderate hazard of wind erosion. • Most climatically suited crops can be grown if • Roots are restricted below a depth of 12 to 20 irrigation water is provided. inches because of the hardpan. • Surface and sprinkler irrigation systems are • Deep chiseling or ripping improves the rooting suited to this soil. depth. Interpretive Groups Interpretive Groups Land capability classification: IIc, irrigated, and Land capability classification: VIe, nonirrigated VIc, nonirrigated Range site: Loamy, 8 to 10 inch precipitation zone 123—Sluka silt loam, 1 to 4 percent slopes 122—Shano silt loam, 1 to 4 percent slopes Composition Sluka soil and similar inclusions—90 percent Composition Contrasting inclusions—10 percent Shano soil and similar inclusions—85 percent Setting Contrasting inclusions—15 percent Position on landscape: Terraces Setting Elevation: 3,500 to 4,000 feet Average annual precipitation: 8 to 10 inches Position on landscape: Terraces Average annual air temperature: 49 to 51 Elevation: 3,500 to 4,000 feet degrees F Average annual precipitation: 8 to 10 inches Frost-free season: 120 to 140 days Average annual air temperature: 47 to 49 degrees F Characteristics of the Sluka Soil Frost-free season: 130 to 140 days Typical profile: 0 to 14 inches—pale brown silt loam Characteristics of the Shano Soil 14 to 22 inches—white silt loam Typical profile: 22 to 39 inches—white lime- and silica- 0 to 5 inches—brown silt loam cemented hardpan over very pale brown 5 to 10 inches—yellowish brown silt loam silt loam Jerome-Twin Falls, Idaho 115

39 to 72 inches—pale brown loam 124—Sluka silt loam, 4 to 8 percent Depth class: Moderately deep to a hardpan slopes Drainage class: Well drained Permeability: Moderate Composition Available water capacity: 3 to 6 inches Sluka soil and similar inclusions—90 percent Potential rooting depth: 20 to 40 inches Contrasting inclusions—10 percent Runoff: Slow Hazard of water erosion: Slight Setting Hazard of wind erosion: Moderate Position on landscape: Terraces Contrasting Inclusions Elevation: 3,500 to 4,500 feet Average annual precipitation: 8 to 10 inches Bahem, Minidoka, and Portneuf soils on terraces; Average annual air temperature: 49 to 51 Minveno soils on higher lying terraces; degrees F Owsel, Paulville, and Rad soils on lower Frost-free season: 120 to 140 days lying terraces; Tulch soils on stream terraces Characteristics of the Sluka Soil Use and Management Typical profile: Major uses: Irrigated cropland, rangeland 0 to 4 inches—pale brown silt loam Major management factors: Precipitation, hazard 4 to 21 inches—very pale brown silt loam of wind erosion 21 to 37 inches—white lime- and silica- Irrigated Cropland cemented hardpan over pale brown loam 37 to 51 inches—pale brown very fine sandy General management considerations: loam • Most climatically suited crops can be grown if 51 to 61 inches—white lime- and silica- irrigation water is provided. cemented hardpan over pale brown loam • Surface and sprinkler irrigation systems are Depth class: Moderately deep to a hardpan suited to this soil. Drainage class: Well drained • Production of irrigated crops is limited by the Permeability: Moderate moderate hazard of wind erosion. Available water capacity: 3 to 6 inches • The risk of wind erosion is reduced by Potential rooting depth: 20 to 40 inches maintaining crop residue on the surface, keeping Runoff: Medium tillage at a minimum, and keeping the surface of Hazard of water erosion: Moderate the soil rough. Hazard of wind erosion: Moderate Rangeland Contrasting Inclusions Dominant vegetation in natural potential plant Bahem, Minidoka, Portneuf, and Shabliss soils community: Thurber needlegrass, Wyoming on terraces; Barrymore soils on higher lying big sagebrush terraces; Shano soils on lower lying terraces General management considerations: • Forage production is limited by low Use and Management precipitation. Major uses: Rangeland, irrigated cropland • Seeding is limited by low precipitation and the Major management factors: Precipitation, slope, moderate hazard of wind erosion. hazard of water erosion, hazard of wind • Seeding generally is most successful late in erosion fall; however, it may not be successful in years when precipitation is below average during the Rangeland growing season. Dominant vegetation in natural potential plant Interpretive Groups community: Thurber needlegrass, Wyoming Land capability classification: IIIe, irrigated, and big sagebrush VIs, nonirrigated General management considerations: Range site: Loamy, 8 to 10 inch precipitation • Forage production is limited by low zone precipitation. 116 Soil Survey

• Seeding is limited by low precipitation and the Runoff: Medium moderate hazards of water and wind erosion. Hazard of water erosion: Moderate • Seeding generally is most successful late in Hazard of wind erosion: Moderate fall; however, it may not be successful in years Contrasting Inclusions when precipitation is below average during the growing season. Bahem soils on the sides of terraces, areas of Rock outcrop Irrigated Cropland Use and Management General management considerations: • Most climatically suited crops can be grown if Major use: Rangeland irrigation water is provided. Major management factors: Precipitation, hazard • Sprinkler irrigation is best suited to this soil, but of water erosion, hazard of wind erosion surface irrigation can be used if the water is Dominant vegetation in natural potential plant regulated to control erosion. community: Thurber needlegrass, Wyoming • Production of irrigated crops is limited by slope big sagebrush and the moderate hazards of water and wind General management considerations: erosion. • Forage production is limited by low precipitation. Interpretive Groups • Seeding is limited by low precipitation and the Land capability classification: IVe, irrigated, and moderate hazards of water and wind erosion. VIe, nonirrigated • Seeding generally is most successful late in Range site: Loamy, 8 to 10 inch precipitation fall; however, it may not be successful in years zone when precipitation is below average during the growing season. 125—Sluka silt loam, 8 to 12 percent Interpretive Groups slopes Land capability classification: VIe, nonirrigated Range site: Loamy, 8 to 10 inch precipitation Composition zone Sluka soil and similar inclusions—90 percent Contrasting inclusions—10 percent 126—Sluka-Purdam association, 15 Setting to 50 percent slopes Position on landscape: Sides of terraces Composition Elevation: 3,500 to 4,500 feet Average annual precipitation: 8 to 10 inches Sluka soil and similar inclusions—50 percent Average annual air temperature: 49 to 51 Purdam soil and similar inclusions—30 percent degrees F Contrasting inclusions—20 percent Frost-free season: 120 to 140 days Setting Characteristics of the Sluka Soil Position on landscape: Sluka soil—plane areas Typical profile: of back slopes; Purdam soil—concave areas 0 to 8 inches—light brownish gray silt loam of back slopes 8 to 24 inches—pale brown silt loam Elevation: 3,000 to 4,000 feet 24 to 60 inches—white lime- and silica- Average annual precipitation: 8 to 10 inches cemented hardpan over very pale brown Average annual air temperature: 49 to 51 loam degrees F Depth class: Moderately deep to a hardpan Frost-free season: 130 to 140 days Drainage class: Well drained Characteristics of the Sluka Soil Permeability: Moderate Available water capacity: 3 to 6 inches Slope range: 15 to 50 percent Potential rooting depth: 20 to 40 inches Typical profile: Jerome-Twin Falls, Idaho 117

0 to 4 inches—light brownish gray silt loam Interpretive Groups 4 to 23 inches—very pale brown silt loam Land capability classification: VIIe, nonirrigated 23 to 50 inches—lime- and silica-cemented Range site: Loamy, 8 to 10 inch precipitation hardpan over very pale brown silt loam zone 50 to 64 inches—pale brown sandy loam Depth class: Moderately deep to a hardpan Drainage class: Well drained 127—Stricker-Nawt-Rock outcrop Permeability: Moderate association, 15 to 30 percent Available water capacity: 3 to 6 inches slopes Potential rooting depth: 20 to 40 inches Runoff: Rapid Composition Hazard of water erosion: Severe Hazard of wind erosion: Moderate Stricker soil and similar inclusions—40 percent Nawt soil and similar inclusions—30 percent Characteristics of the Purdam Soil Rock outcrop—15 percent Slope range: 15 to 30 percent Contrasting inclusions—15 percent Typical profile: Setting 0 to 5 inches—brown silt loam 5 to 18 inches—pale brown silt loam Position on landscape: Stricker soil—north- and 18 to 27 inches—pale brown silty clay loam east-facing slopes of breaks; Nawt soil— 27 to 38 inches—very pale brown loam south- and west-facing slopes of breaks 38 to 65 inches—lime- and silica-cemented Elevation: 4,300 to 6,000 feet hardpan over very pale brown very fine Average annual precipitation: 12 to 16 inches sandy loam Average annual air temperature: 46 to 50 Depth class: Moderately deep to a hardpan degrees F Drainage class: Well drained Frost-free season: 100 to 110 days Permeability: Moderately slow Characteristics of the Stricker Soil Available water capacity: 4.5 to 7.5 inches Potential rooting depth: 20 to 40 inches Typical profile: Runoff: Rapid 0 to 3 inches—brown very stony loam Hazard of water erosion: Severe 3 to 6 inches—brown gravelly silt loam Shrink-swell potential: Moderate 6 to 16 inches—brown very gravelly silt loam 16 to 30 inches—very pale brown extremely Contrasting Inclusions cobbly loam Bahem soils on the sides of terraces, Blacknest 30 to 60 inches—very pale brown very and Rakane soils on lower lying terraces cobbly loam Depth class: Very deep Use and Management Drainage class: Well drained Major use: Rangeland Permeability: Moderate Major management factors: Precipitation, slope, Available water capacity: 4.0 to 5.5 inches hazard of water erosion, hazard of wind Potential rooting depth: 60 inches or more erosion Runoff: Rapid Dominant vegetation in natural potential plant Hazard of water erosion: Severe community: Thurber needlegrass, Wyoming Characteristics of the Nawt Soil big sagebrush General management considerations: Typical profile: • Forage production is limited by low 0 to 3 inches—brown extremely stony loam precipitation. 3 to 8 inches—brown gravelly clay • Seeding is limited by slope, by the severe 8 to 35 inches—yellowish brown gravelly silty hazard of water erosion, and by the moderate clay hazard of wind erosion on the Sluka soil. 35 to 44 inches—pale brown gravelly silt • The use of equipment is limited by slope. loam 118 Soil Survey

44 to 60 inches—decomposing bedrock 128—Stricker-Nawt-Rock outcrop Depth class: Deep to bedrock association, 30 to 75 percent Drainage class: Well drained slopes Permeability: Slow Available water capacity: 3.5 to 7.0 inches Composition Potential rooting depth: 40 to 60 inches Runoff: Rapid Stricker soil and similar inclusions—45 percent Hazard of water erosion: Severe Nawt soil and similar inclusions—25 percent Shrink-swell potential: High Rock outcrop—20 percent Contrasting inclusions—10 percent Characteristics of the Rock Outcrop Kind of rock: Exposed welded tuff Setting Description of areas: Sharp, angular cliffs and Position on landscape: Stricker soil—north- and rimrock that border lower lying valley east-facing slopes of breaks; Nawt soil— terraces and large, angular fragments that south- and west-facing slopes of breaks (fig. separated from the cliffs and rimrock and 9) were randomly deposited downslope Contrasting Inclusions Bahem, Chuska, Kecko, and Schnipper soils on lower lying terraces; Congle soils on north- and east-facing foot slopes and back slopes; Gosinta soils on alluvial terraces; Mackey soils on dip slopes; very deep cobbly loam on breaks; soils that are moderately deep to bedrock, are very stony loam over very gravelly loam, and are on breaks; soils that are moderately deep to bedrock, are very stony loam over very gravelly clay, and are on breaks; outcroppings of limestone near Nat-Soo-Pah; outcroppings of volcanic ash Use and Management Figure 9.—Area of Stricker-Nawt-Rock outcrop Major use: Rangeland association, 30 to 75 percent slopes. Stricker soil is Major management factors: Rock fragments in on north and east aspects, and Nawt soil is on west the surface layer, areas of Rock outcrop, and south aspects. hazard of water erosion Dominant vegetation in natural potential plant Elevation: 4,300 to 6,000 feet community: Stricker and Nawt soils— Average annual precipitation: 12 to 16 inches bluebunch wheatgrass, Wyoming big Average annual air temperature: 46 to 50 sagebrush degrees F General management considerations: Frost-free season: 100 to 110 days • Seeding is limited by the rock fragments in the surface layer, severe hazard of water erosion, Characteristics of the Stricker Soil and areas of Rock outcrop. Typical profile: Interpretive Groups 0 to 3 inches—grayish brown very stony loam Land capability classification: VIIs, nonirrigated 3 to 12 inches—brown gravelly loam Range site: Stricker and Nawt soils—Stony loam, 12 to 22 inches—pale brown extremely 12 to 16 inch precipitation zone cobbly loam Jerome-Twin Falls, Idaho 119

22 to 29 inches—very pale brown extremely Use and Management cobbly loam Major use: Rangeland 29 to 61 inches—very pale brown extremely Major management factors: Slope, rock cobbly sandy loam fragments in the surface layer, areas of Rock Depth class: Very deep outcrop, hazard of water erosion Drainage class: Well drained Dominant vegetation in natural potential plant Permeability: Moderate community: Nawt and Stricker soils— Available water capacity: 4.0 to 5.5 inches bluebunch wheatgrass, Wyoming big Potential rooting depth: 60 inches or more sagebrush Runoff: Rapid General management considerations: Hazard of water erosion: Very severe • Seeding is limited by the slope, rock fragments Characteristics of the Nawt Soil in the surface layer, areas of Rock outcrop, and very severe hazard of water erosion. Typical profile: • The use of equipment is limited by the slope, 0 to 5 inches—brown extremely stony loam rock fragments in the surface layer, and areas of 5 to 18 inches—brown gravelly clay Rock outcrop. 18 to 36 inches—light yellowish brown gravelly clay Interpretive Groups 36 to 45 inches—very pale brown very Land capability classification: VIIe, nonirrigated gravelly clay loam Range site: Stricker and Nawt soils—South slope 45 to 62 inches—decomposing bedrock stony, 10 to 13 inch precipitation zone Depth class: Deep to bedrock Drainage class: Well drained Permeability: Slow 129—Suepert-Taunton complex, 1 to Available water capacity: 3.5 to 7.0 inches 15 percent slopes Potential rooting depth: 40 to 60 inches Runoff: Rapid Composition Hazard of water erosion: Very severe Shrink-swell potential: High Suepert soil and similar inclusions—60 percent Taunton soil and similar inclusions—30 percent Characteristics of the Rock Outcrop Contrasting inclusions—10 percent Kind of rock: Exposed welded tuff Setting Description of areas: Sharp, angular cliffs and rimrock that border lower lying valley Position on landscape: Suepert soil—convex terraces and large, angular fragments that areas of terraces; Taunton soil—concave or separated from the cliffs and rimrock and plane areas of terraces were randomly deposited downslope Elevation: 3,000 to 4,000 feet Average annual precipitation: 9 to 10 inches Contrasting Inclusions Average annual air temperature: 50 to 52 Doodlelink soils on north- and east-facing slopes degrees F of breaks; Flatron and Ragpie soils on Frost-free season: 130 to 140 days ridges; Gosinta soils on alluvial terraces; Characteristics of the Suepert Soil Mackey soils on dip slopes; very deep stony loam on breaks; soils that are moderately Slope range: 1 to 15 percent deep to bedrock, are very stony loam over Typical profile: very cobbly loam, and are on breaks; soils 0 to 8 inches—yellowish brown extremely that are moderately deep to bedrock, are stony silt loam very stony loam over gravelly clay, and are 8 to 18 inches—yellowish brown very cobbly on breaks; outcroppings of volcanic ash silt loam 120 Soil Survey

18 to 32 inches—yellowish brown extremely • The use of equipment is limited by the rock cobbly silt loam fragments in the surface layer of the Suepert soil. 32 to 48 inches—white very cobbly lime- and Interpretive Groups silica-cemented hardpan 48 to 80 inches—lime-coated gravel, Land capability classification: VIIs, nonirrigated cobbles, and stones Range site: Loamy, 8 to 12 inch precipitation Depth class: Moderately deep to a hardpan zone Drainage class: Well drained Permeability: Moderate Available water capacity: 1.5 to 2.5 inches 130—Tanner silt loam, 1 to 10 percent Potential rooting depth: 20 to 40 inches slopes Runoff: Slow Hazard of water erosion: Slight Composition Characteristics of the Taunton Soil Tanner soil and similar inclusions—80 percent Contrasting inclusions—20 percent Slope range: 1 to 8 percent Typical profile: Setting 0 to 19 inches—pale brown fine sandy loam Position on landscape: Terraces 19 to 36 inches—light gray sandy loam Elevation: 5,200 to 5,900 feet 36 to 44 inches—white lime- and silica- Average annual precipitation: 10 to 13 inches cemented hardpan Average annual air temperature: 43 to 46 Depth class: Moderately deep to a hardpan degrees F Drainage class: Well drained Frost-free season: 90 to 100 days Permeability: Moderate Available water capacity: 3.5 to 6.5 inches Characteristics of the Tanner Soil Potential rooting depth: 20 to 40 inches Runoff: Slow Typical profile: Hazard of water erosion: Slight 0 to 3 inches—brown silt loam Hazard of wind erosion: Moderate 3 to 16 inches—brown silty clay loam 16 to 22 inches—pale brown cobbly silty clay Contrasting Inclusions 22 to 35 inches—very pale brown loam Banbury soils on higher lying terraces; Minidoka, 35 to 51 inches—white fractured lime- and Paulville, and Scoon soils on lower lying silica-cemented hardpan terraces; areas of Rock outcrop 51 inches—bedrock Depth class: Moderately deep to a hardpan Use and Management Drainage class: Well drained Major use: Rangeland Permeability: Slow Major management factors: Precipitation, rock Available water capacity: 3.5 to 6.5 inches fragments in the surface layer of the Suepert Potential rooting depth: 20 to 40 inches soil, hazard of wind erosion on the Taunton Runoff: Medium soil Hazard of water erosion: Moderate Dominant vegetation in natural potential plant Shrink-swell potential: High community: Bluebunch wheatgrass, Wyoming big sagebrush Contrasting Inclusions General management considerations: • Forage production is limited by low Aninto and Oshone soils on lower lying terraces; precipitation. Budlewis, Chayson, and Forvic soils on • Seeding is limited by low precipitation, the rock higher lying terraces; soils that are fragments in the surface layer of the Suepert soil, moderately deep to bedrock, are silt loam and the moderate hazard of wind erosion on the over silty clay loam over silty clay, and are on Taunton soil. terraces Jerome-Twin Falls, Idaho 121

Use and Management Depth class: Moderately deep to a hardpan Drainage class: Well drained Major use: Rangeland Permeability: Slow Major management factors: Precipitation, hazard Available water capacity: 3.5 to 6.5 inches of water erosion Potential rooting depth: 20 to 40 inches Dominant vegetation in natural potential plant Runoff: Medium community: Bluebunch wheatgrass, basin big Hazard of water erosion: Moderate sagebrush Shrink-swell potential: High General management considerations: • Forage production is limited by low Characteristics of the Pigtail Soil precipitation. Slope range: 1 to 3 percent • Seeding is limited by low precipitation and the Typical profile: moderate hazard of water erosion. 0 to 3 inches—pale brown silt loam • Seeding generally is most successful late in 3 to 7 inches—pale brown silty clay loam fall; however, it may not be successful in years 7 to 18 inches—pale brown silty clay when precipitation is below average during the 18 to 32 inches—very pale brown loam growing season. 32 to 60 inches—white fractured lime- and Interpretive Groups silica-cemented hardpan Depth class: Moderately deep to a hardpan Land capability classification: IVe, nonirrigated Drainage class: Well drained Range site: Loamy, 11 to 13 inch precipitation Permeability: Very slow zone Available water capacity: 4.0 to 7.5 inches Potential rooting depth: 20 to 40 inches 131—Tanner-Pigtail complex, 1 to 8 Runoff: Slow percent slopes Hazard of water erosion: Slight Shrink-swell potential: High Composition Contrasting Inclusions Tanner soil and similar inclusions—60 percent Elijah soils on higher lying terraces; soils that are Pigtail soil and similar inclusions—30 percent moderately deep to bedrock, are silt loam Contrasting inclusions—10 percent over silty clay over silt loam, and are in convex areas of terraces; soils that are Setting moderately deep to a hardpan, are silt loam, Position on landscape: Tanner soil—convex and are in convex areas of terraces areas of terraces, Pigtail soil—plane or Use and Management concave areas of terraces Elevation: 5,300 to 5,500 feet Major use: Rangeland Average annual precipitation: 9 to 11 inches Major management factors: Precipitation, depth Average annual air temperature: 45 to 48 to the clayey subsoil in the Pigtail soil, degrees F hazard of water erosion on the Tanner soil Frost-free season: 100 to 110 days Dominant vegetation in natural potential plant community: Tanner soil—bluebunch Characteristics of the Tanner Soil wheatgrass, Wyoming big sagebrush; Pigtail Slope range: 1 to 8 percent soil—Thurber needlegrass, Wyoming big Typical profile: sagebrush 0 to 5 inches—grayish brown silt loam General management considerations: 5 to 14 inches—brown silty clay • Forage production is limited by low 14 to 26 inches—very pale brown silt loam precipitation and the shallow depth to the clayey 26 to 46 inches—white fractured lime- and subsoil in the Pigtail soil. silica-cemented hardpan • Plant rooting depth is limited to the upper part 46 to 65 inches—very pale brown sandy of the Pigtail soil because of the claypan. loam • Seeding is limited by low precipitation and by 122 Soil Survey

the moderate hazard of water erosion on the Use and Management Tanner soil. Major use: Irrigated cropland • Seeding generally is most successful late in Major management factor: Hazard of wind fall; however, it may not be successful in years erosion when precipitation is below average during the General management considerations: growing season. • Most climatically suited crops can be grown if Interpretive Groups irrigation water is provided. • Surface and sprinkler irrigation systems are Land capability classification: VIs, nonirrigated suited to this soil. Range site: Tanner soil—Loamy, 10 to 13 inch • Production of irrigated crops is limited by the precipitation zone; Pigtail soil—Slick spot moderate hazard of wind erosion. sodic, 8 to 12 inch precipitation zone Interpretive Groups 132—Taunton sandy loam, 1 to 4 Land capability classification: IIIs, irrigated, and percent slopes VIs, nonirrigated

Composition 133—Taunton sandy loam, 4 to 8 Taunton soil and similar inclusions—85 percent percent slopes Contrasting inclusions—15 percent Composition Setting Taunton soil and similar inclusions—85 percent Position on landscape: Terraces Contrasting inclusions—15 percent Elevation: 3,700 to 4,000 feet Average annual precipitation: 8 to 10 inches Setting Average annual air temperature: 48 to 50 Position on landscape: Terraces degrees F Elevation: 3,700 to 4,000 feet Frost-free season: 120 to 140 days Average annual precipitation: 8 to 10 inches Average annual air temperature: 48 to 50 Characteristics of the Taunton Soil degrees F Typical profile: Frost-free season: 120 to 140 days 0 to 3 inches—brown sandy loam Characteristics of the Taunton Soil 3 to 12 inches—brown fine sandy loam 12 to 29 inches—pale brown fine sandy loam Typical profile: 29 to 38 inches—very pale brown gravelly 0 to 5 inches—pale brown sandy loam loam 5 to 22 inches—brown fine sandy loam 38 to 52 inches—white fractured lime- and 22 to 36 inches—pale brown fine sandy loam silica-cemented hardpan 36 inches—white lime- and silica-cemented Depth class: Moderately deep to a hardpan hardpan Drainage class: Well drained Depth class: Moderately deep to a hardpan Permeability: Moderate Drainage class: Well drained Available water capacity: 3.5 to 6.5 inches Permeability: Moderate Potential rooting depth: 20 to 40 inches Available water capacity: 3.5 to 6.5 inches Runoff: Slow Potential rooting depth: 20 to 40 inches Hazard of water erosion: Slight Runoff: Medium Hazard of wind erosion: Moderate Hazard of water erosion: Moderate Hazard of wind erosion: Moderate Contrasting Inclusions Contrasting Inclusions Emberton and Kecko soils on lower lying Jestrick and Kecko soils on terraces, areas of terraces Rock outcrop Jerome-Twin Falls, Idaho 123

Use and Management Use and Management Major use: Irrigated cropland Major use: Irrigated cropland Major management factors: Slope, hazard of Major management factor: Hazard of wind water erosion, hazard of wind erosion erosion General management considerations: General management considerations: • Most climatically suited crops can be grown if • Most climatically suited crops can be grown if irrigation water is provided. irrigation water is provided. • Sprinkler irrigation is best suited to this soil, but • Surface and sprinkler irrigation systems are surface irrigation can be used if the water is suited to this soil. regulated to control erosion. • Production of irrigated crops is limited by the • Production of irrigated crops is limited by slope moderate hazard of wind erosion. and the moderate hazards of water and wind Interpretive Groups erosion. Land capability classification: IIIe, irrigated, and Interpretive Groups VIe, nonirrigated Land capability classification: IIIe, irrigated, and VIe, nonirrigated 135—Tock loam, 1 to 6 percent slopes 134—Taunton silt loam, 2 to 4 percent Composition slopes Tock soil and similar inclusions—85 percent Contrasting inclusions—15 percent Composition Setting Taunton soil and similar inclusions—90 percent Position on landscape: Terraces Contrasting inclusions—10 percent Elevation: 5,200 to 5,600 feet Setting Average annual precipitation: 12 to 14 inches Average annual air temperature: 43 to 45 Position on landscape: Terraces degrees F Elevation: 3,700 to 4,100 feet Frost-free season: 90 to 100 days Average annual precipitation: 8 to 10 inches Average annual air temperature: 48 to 50 Characteristics of the Tock Soil degrees F Typical profile: Frost-free season: 120 to 140 days 0 to 4 inches—pale brown loam Characteristics of the Taunton Soil 4 to 13 inches—brown silty clay loam 13 to 30 inches—yellowish brown silty clay Typical profile: 30 to 36 inches—light yellowish brown lime- 0 to 5 inches—pale brown silt loam and silica-cemented hardpan 5 to 19 inches—pale brown silt loam 36 to 60 inches—multicolored sand and 19 to 36 inches—very pale brown loam gravel 36 inches—white lime- and silica-cemented Depth class: Moderately deep to a hardpan hardpan Drainage class: Well drained Depth class: Moderately deep to a hardpan Permeability: Slow Drainage class: Well drained Available water capacity: 3.5 to 6.0 inches Permeability: Moderate Potential rooting depth: 20 to 40 inches Available water capacity: 3 to 6 inches Runoff: Medium Potential rooting depth: 20 to 40 inches Hazard of water erosion: Moderate Runoff: Slow Shrink-swell potential: High Hazard of water erosion: Slight Hazard of wind erosion: Moderate Contrasting Inclusions Chuska soils on lower lying terraces, Oshone Contrasting Inclusions soils on higher lying terraces, very deep silt Minveno and Sluka soils on terraces loam on terraces 124 Soil Survey

Use and Management Contrasting Inclusions Major use: Rangeland Minveno soils on higher lying terraces; soils that Major management factors: Precipitation, hazard are moderately deep to bedrock, are silt of water erosion loam, and are on terraces Dominant vegetation in natural potential plant Use and Management community: Bluebunch wheatgrass, Wyoming big sagebrush Major use: Irrigated cropland General management considerations: Major management factors: Depth to bedrock, • Forage production is limited by low available water capacity precipitation. General management considerations: • Seeding is limited by low precipitation and the • Most climatically suited crops can be grown if moderate hazard of water erosion. irrigation water is provided. • Seeding generally is most successful late in • Surface and sprinkler irrigation systems are fall; however, it may not be successful in years suited to this soil. when precipitation is below average during the • Production of irrigated crops is limited by the growing season. shallow rooting depth and low available water capacity. Interpretive Groups Interpretive Groups Land capability classification: VIs, nonirrigated Range site: Loamy, 10 to 13 inch precipitation Land capability classification: IVs, irrigated, and zone VIs, nonirrigated

136—Trevino silt loam, 0 to 2 percent 137—Trevino silt loam, 2 to 8 percent slopes slopes

Composition Composition Trevino soil and similar inclusions—95 percent Trevino soil and similar inclusions—95 percent Contrasting inclusions—5 percent Contrasting inclusions—5 percent Setting Setting Position on landscape: Terraces Position on landscape: Terraces Elevation: 3,500 to 4,500 feet Elevation: 3,500 to 4,500 feet Average annual precipitation: 8 to 10 inches Average annual precipitation: 8 to 10 inches Average annual air temperature: 49 to 51 Average annual air temperature: 49 to 51 degrees F degrees F Frost-free season: 120 to 140 days Frost-free season: 120 to 140 days Characteristics of the Trevino Soil Characteristics of the Trevino Soil Typical profile: Typical profile: 0 to 3 inches—light brownish gray silt loam 0 to 5 inches—pale brown silt loam 3 to 11 inches—light brownish gray silt loam 5 to 10 inches—brown silt loam 11 to 18 inches—light gray silt loam 10 to 16 inches—very pale brown silt loam 18 inches—bedrock 16 inches—bedrock Depth class: Shallow to bedrock Depth class: Shallow to bedrock Drainage class: Well drained Drainage class: Well drained Permeability: Moderate Permeability: Moderate Available water capacity: 2.5 to 4.0 inches Available water capacity: 2.5 to 4.0 inches Potential rooting depth: 10 to 20 inches Potential rooting depth: 10 to 20 inches Runoff: Slow Runoff: Medium Hazard of water erosion: Slight Hazard of water erosion: Moderate Jerome-Twin Falls, Idaho 125

Contrasting Inclusions Setting Minveno soils on higher lying terraces; soils that Position on landscape: Terraces are moderately deep to bedrock, are silt Elevation: 3,000 to 4,500 feet loam, and are on terraces Average annual precipitation: 8 to 10 inches Average annual air temperature: 49 to 51 Use and Management degrees F Major uses: Irrigated cropland, rangeland Frost-free season: 120 to 140 days Major management factors: Precipitation, depth Characteristics of the Trevino Soil to bedrock, available water capacity, slope, hazard of water erosion Slope range: 2 to 20 percent Typical profile: Irrigated Cropland 0 to 4 inches—pale brown silt loam General management considerations: 4 to 14 inches—pale brown silt loam • Most climatically suited crops can be grown if 14 to 18 inches—light brownish gray silt irrigation water is provided. loam • Sprinkler irrigation is best suited to this soil, but 18 inches—bedrock surface irrigation can be used if the water is Depth class: Shallow to bedrock regulated to control erosion. Drainage class: Well drained • Production of irrigated crops is limited by the Permeability: Moderate shallow rooting depth, low available water Available water capacity: 2.5 to 4.0 inches capacity, slope, and moderate hazard of water Potential rooting depth: 10 to 20 inches erosion. Runoff: Medium Hazard of water erosion: Moderate Rangeland Characteristics of the Rock Outcrop Dominant vegetation in natural potential plant community: Bluebunch wheatgrass, Kind of rock: Exposed basalt Wyoming big sagebrush Description of areas: Sharp, angular to General management considerations: semirounded, long, narrow, lava flow • Forage production is limited by low pressure ridges ranging to semirounded precipitation, shallow rooting depth, and low outcroppings that extend 1 foot to 10 feet available water capacity. above the adjacent landscape • Seeding is limited by low precipitation and the Contrasting Inclusions moderate hazard of water erosion. • Seeding generally is most successful late in Minveno soils on higher lying terraces, very fall; however, it may not be successful in years shallow silt loam on terraces when precipitation is below average during the growing season. Use and Management Interpretive Groups Major use: Rangeland Major management factors: Precipitation, depth Land capability classification: IVe, irrigated, and to bedrock, available water capacity, areas of VIe, nonirrigated Rock outcrop, hazard of water erosion Range site: Shallow loamy, 8 to 12 inch Dominant vegetation in natural potential plant precipitation zone community: Trevino soil—bluebunch wheatgrass, Wyoming big sagebrush 138—Trevino-Rock outcrop complex, General management considerations: 2 to 20 percent slopes • Forage production is limited by low precipitation, shallow rooting depth, and low Composition available water capacity. Trevino soil and similar inclusions—70 percent • Seeding is limited by the low precipitation, Rock outcrop—20 percent areas of Rock outcrop, and moderate hazard of Contrasting inclusions—10 percent water erosion. 126 Soil Survey

Interpretive Groups Use and Management Land capability classification: VIIs, nonirrigated Major use: Rangeland Range site: Trevino soil—Shallow loamy, 8 to 12 Major management factor: Wetness inch precipitation zone Dominant vegetation in natural potential plant community: Slender wheatgrass, sedges General management considerations: 139—Tucker silt loam, 0 to 2 percent • Seeding is limited by wetness. slopes • Plants that tolerate wetness are suitable for seeding. Composition • Grazing should be delayed until the soil is adequately drained and is firm enough to Tucker soil and similar inclusions—85 percent withstand tramping by livestock. Contrasting inclusions—15 percent Interpretive Groups Setting Land capability classification: IIIw, nonirrigated Position on landscape: Terraces and flood plains Range site: Semi-wet meadow Elevation: 5,200 to 6,500 feet Average annual precipitation: 12 to 16 inches Average annual air temperature: 43 to 45 140—Tulch silt loam, 0 to 2 percent degrees F slopes Frost-free season: 80 to 100 days Characteristics of the Tucker Soil Composition Typical profile: Tulch soil and similar inclusions—90 percent 0 to 6 inches—dark grayish brown silt loam Contrasting inclusions—10 percent 6 to 11 inches—dark grayish brown silty clay Setting loam 11 to 32 inches—dark grayish brown silty Position on landscape: Stream terraces clay Elevation: 3,000 to 4,000 feet 32 to 70 inches—gray silty clay Average annual precipitation: 8 to 10 inches Depth class: Very deep Average annual air temperature: 48 to 50 Drainage class: Somewhat poorly drained degrees F Permeability: Slow Frost-free season: 120 to 140 days Available water capacity: 9.5 to 11.0 inches Potential rooting depth: 60 inches or more Characteristics of the Tulch Soil Runoff: Slow Hazard of water erosion: Slight Typical profile: Depth to water table: 18 to 36 inches 0 to 3 inches—brown silt loam Frequency of flooding: Rare 3 to 9 inches—pale brown silt loam Shrink-swell potential: High 9 to 38 inches—pale brown silty clay loam 38 to 70 inches—very pale brown silty clay Contrasting Inclusions loam Zola soils on higher lying terraces; very deep, Depth class: Very deep poorly drained soils that are silt loan over Drainage class: Well drained silty clay loam over silty clay and are in Permeability: Moderately slow depressional areas of lower lying terraces; Available water capacity: 10 to 12 inches very deep, well drained loam on higher lying Potential rooting depth: 60 inches or more terraces Runoff: Slow Jerome-Twin Falls, Idaho 127

Hazard of water erosion: Slight Setting Shrink-swell potential: Moderate Position on landscape: Hillsides Contrasting Inclusions Elevation: 5,000 to 6,000 feet Average annual precipitation: 10 to 13 inches Paulville and Shano soils on lower lying terraces; Average annual air temperature: 45 to 48 Portneuf and Sluka soils on higher lying degrees F terraces Frost-free season: 100 to 110 days Use and Management Characteristics of the Udaho Soil Major uses: Rangeland, irrigated cropland Typical profile: Major management factors: Precipitation, 0 to 7 inches—pale brown very gravelly loam permeability 7 to 29 inches—white very gravelly sandy Rangeland loam 29 to 60 inches—partially consolidated Dominant vegetation in natural potential plant volcanic ash community: Basin wildrye, basin big Depth class: Moderately deep to bedrock sagebrush Drainage class: Well drained General management considerations: Permeability: Moderately rapid • Forage production and seeding are limited Available water capacity: 5 to 6 inches mainly by low precipitation. Potential rooting depth: 20 to 40 inches • Seeding generally is most successful late in Runoff: Medium fall; however, it may not be successful in years Hazard of water erosion: Moderate when precipitation is below average during the Salinity: Moderate between depths of 7 and 29 growing season. inches Irrigated Cropland Contrasting Inclusions General management considerations: Ackett soils on stream terraces; Chuska, • Most climatically suited crops can be grown if Lankbush, and Weash soils on lower lying irrigation water is provided. terraces; soils that are moderately deep to • Surface and sprinkler irrigation systems are bedrock, are gravelly loam over gravelly suited to this soil. sandy loam, and are on hillsides; soils that • Because of the moderately slow permeability, are shallow to bedrock, are very gravelly the application of irrigation water should be loam over very gravelly sandy loam, and are adjusted to the water intake rate. on hillsides; areas of Rock outcrop; Interpretive Groups outcroppings of volcanic ash Land capability classification: IIc, irrigated, and Use and Management VIc, nonirrigated Major use: Rangeland Range site: Loamy bottom, 8 to 14 inch Major management factors: Precipitation, rock precipitation zone fragments in the surface layer, hazard of water erosion 141—Udaho very gravelly loam, 10 to Dominant vegetation in natural potential plant 30 percent slopes community: Bluebunch wheatgrass, Wyoming big sagebrush General management considerations: Composition • Forage production is limited by low Udaho soil and similar inclusions—85 percent precipitation. Contrasting inclusions—15 percent • Seeding is limited by the low precipitation, rock 128 Soil Survey

fragments in the surface layer, and moderate fragments in the surface layer, slope, hazard hazard of water erosion. of water erosion Dominant vegetation in natural potential plant Interpretive Groups community: Indian ricegrass, Wyoming big Land capability classification: VIIs, nonirrigated sagebrush Range site: Stony loam, 12 to 16 inch General management considerations: precipitation zone • Forage production is limited by low precipitation. • The use of forage is limited by slope. 142—Udaho very gravelly loam, 30 to • Seeding is limited by low precipitation, rock 65 percent slopes fragments in the surface layer, slope, and the severe hazard of water erosion. Composition • The use of equipment is limited by slope. Udaho soil and similar inclusions—85 percent Interpretive Groups Contrasting inclusions—15 percent Land capability classification: VIIe, nonirrigated Setting Range site: Ashy south slope, 10 to 16 inch precipitation zone Position on landscape: Breaks Elevation: 5,000 to 6,000 feet Average annual precipitation: 10 to 13 inches 143—Wagonjacket silt loam, 0 to 1 Average annual air temperature: 45 to 48 percent slopes degrees F Frost-free season: 100 to 110 days Composition Characteristics of the Udaho Soil Wagonjacket soil and similar inclusions—80 Typical profile: percent 0 to 7 inches—pale brown very gravelly loam Contrasting inclusions—20 percent 7 to 31 inches—very pale brown very Setting gravelly loam 31 to 60 inches—partially consolidated Position on landscape: Flood plains volcanic ash Elevation: 5,600 to 5,800 feet Depth class: Moderately deep to bedrock Average annual precipitation: 14 to 16 inches Drainage class: Well drained Average annual air temperature: 42 to 45 Permeability: Moderately rapid degrees F Available water capacity: 5 to 6 inches Frost-free season: 90 to 105 days Potential rooting depth: 20 to 40 inches Characteristics of the Wagonjacket Soil Runoff: Rapid Hazard of water erosion: Severe Typical profile: Salinity: Moderate between depths of 7 and 31 0 to 3 inches—dark gray silt loam inches 3 to 11 inches—gray silt loam 11 to 26 inches—grayish brown silt loam Contrasting Inclusions 26 to 46 inches—light brownish gray silt Soils that are shallow to bedrock, are very stony loam loam over gravelly clay, and are on breaks; 46 to 61 inches—light gray gravelly sandy soils that are shallow to bedrock, are very loam gravelly loam, and are on breaks; areas of 61 to 70 inches—multicolored sand and Rock outcrop; outcroppings of volcanic ash gravel Depth class: Very deep Use and Management Drainage class: Somewhat poorly drained Major use: Rangeland Permeability: Moderate Major management factors: Precipitation, rock Available water capacity: 8 to 10 inches Jerome-Twin Falls, Idaho 129

Potential rooting depth: 60 inches or more 2 to 8 inches—brown sandy clay loam Runoff: Very slow 8 to 12 inches—brown clay loam Hazard of water erosion: Slight 12 to 60 inches—white weakly consolidated Depth to water table: 18 to 30 inches volcanic ash Frequency of flooding: Frequent Depth class: Shallow to bedrock Drainage class: Well drained Contrasting Inclusions Permeability: Moderately slow Tucker soils on flood plains; Zola soils on higher Available water capacity: 1.5 to 3.0 inches lying terraces; very deep, poorly drained Potential rooting depth: 10 to 20 inches soils that are silt loam over silty clay loam Runoff: Medium over silty clay and are in depressional areas Hazard of water erosion: Moderate of lower lying terraces; somewhat poorly Hazard of wind erosion: Moderate drained soils that are moderately deep to Contrasting Inclusions sand and gravel, are loam over sandy loam, and are on flood plains Arbidge soils on lower lying terraces; Chuska and Lankbush soils on higher lying terraces; Use and Management Udaho soils on hillsides; soils that are Major use: Rangeland moderately deep to bedrock, are gravelly Major management factors: Wetness sandy loam over clay loam, and are on the Dominant vegetation in natural potential plant sides of terraces; outcroppings of volcanic community: Slender wheatgrass, sedges ash General management considerations: Use and Management • Seeding is limited by wetness. • Plants that tolerate wetness are suitable for Major use: Rangeland seeding. Major management factors: Precipitation, • Grazing should be delayed until the soil is available water capacity, hazard of water adequately drained and is firm enough to erosion, hazard of wind erosion withstand tramping by livestock. Dominant vegetation in natural potential plant community: Bluebunch wheatgrass, Interpretive Groups Wyoming big sagebrush Land capability classification: IVw, nonirrigated General management considerations: Range site: Semi-wet meadow • Forage production is limited by low precipitation, shallow rooting depth, and low 144—Weash gravelly sandy loam, 2 to available water capacity. 12 percent slopes • Seeding is limited by low precipitation and the moderate hazards of water and wind erosion. Composition • Seeding generally is most successful late in fall; however, it may not be successful in years Weash soil and similar inclusions—85 percent when precipitation is below average during the Contrasting inclusions—15 percent growing season. Setting Interpretive Groups Position on landscape: Terraces Land capability classification: VIs, nonirrigated Elevation: 5,400 to 5,700 feet Range site: Shallow loamy upland, 10 to 14 inch Average annual precipitation: 10 to 12 inches precipitation zone Average annual air temperature: 45 to 48 degrees F Frost-free season: 100 to 110 days 145—Windypoint-Arbidge complex, 1 to 4 percent slopes Characteristics of the Weash Soil Composition Typical profile: 0 to 2 inches—pale brown gravelly sandy Windypoint soil and similar inclusions—50 loam percent 130 Soil Survey

Arbidge soil and similar inclusions—30 percent Contrasting inclusions—20 percent Setting Position on landscape: Terraces Elevation: 4,400 to 4,700 feet Average annual precipitation: 8 to 10 inches Average annual air temperature: 47 to 49 degrees F Frost-free season: 110 to 120 days Characteristics of the Windypoint Soil Typical profile: 0 to 3 inches—pale brown loam 3 to 28 inches—pale brown gravelly loam 28 to 34 inches—light gray extremely gravelly sandy loam 34 to 65 inches—multicolored sand and Figure 10.—Area of Windypoint-Arbidge complex, 1 to 4 gravel percent slopes. Potatoes on Windypoint soil in foreground. Depth class: Very deep Drainage class: Well drained Major management factors: Precipitation, Permeability: Moderately slow over very rapid permeability Available water capacity: 5 to 7 inches Potential rooting depth: 20 to 40 inches Rangeland Runoff: Slow Dominant vegetation in natural potential plant Hazard of water erosion: Slight community: Thurber needlegrass, Wyoming Shrink-swell potential: Moderate big sagebrush Characteristics of the Arbidge Soil General management considerations: • Forage production and seeding are limited Typical profile: mainly by low precipitation. 0 to 24 inches—pale brown loam • Seeding generally is most successful late in 24 to 36 inches—white lime- and silica- fall; however, it may not be successful in years cemented hardpan when precipitation is below average during the 36 to 64 inches—multicolored extremely growing season. gravelly sand Depth class: Moderately deep to a hardpan Irrigated Cropland Drainage class: Well drained Permeability: Moderately slow General management considerations: Available water capacity: 2.5 to 5.0 inches • Most climatically suited crops can be grown if Potential rooting depth: 20 to 40 inches irrigation water is provided. Runoff: Slow • Surface and sprinkler irrigation systems are Hazard of water erosion: Slight suited to this soil. Shrink-swell potential: Moderate • Because of the moderately slow permeability, the application of irrigation water should be Contrasting Inclusions adjusted to the water intake rate. Blacknest, Paulville, and Taunton soils on terraces; Chuska, Colthorp, and Shabliss Interpretive Groups soils on higher lying terraces Land capability classification: VIs, nonirrigated, Use and Management and IIIs, irrigated Major uses: Rangeland, irrigated cropland (fig. Range site: Loamy, 8 to 10 inch precipitation 10) zone Jerome-Twin Falls, Idaho 131

146—Yahoo silt loam, 0 to 1 percent • Production of irrigated crops is limited by the slopes shallow rooting depth, low available water capacity, and moderate hazard of wind erosion. Composition Interpretive Groups Yahoo soil and similar inclusions—90 percent Land capability classification: IVs, irrigated, and Contrasting inclusions—10 percent VIs, nonirrigated Setting Position on landscape: Terraces 147—Yahoo silt loam, 1 to 4 percent Elevation: 3,400 to 4,300 feet slopes Average annual precipitation: 8 to 10 inches Average annual air temperature: 47 to 49 Composition degrees F Yahoo soil and similar inclusions—90 percent Frost-free season: 120 to 140 days Contrasting inclusions—10 percent Characteristics of the Yahoo Soil Setting Typical profile: Position on landscape: Terraces 0 to 3 inches—pale brown silt loam Elevation: 3,400 to 4,300 feet 3 to 12 inches—pale brown silty clay loam Average annual precipitation: 8 to 10 inches 12 to 20 inches—white lime- and silica- Average annual air temperature: 47 to 49 cemented hardpan over very pale brown degrees F loam Frost-free season: 120 to 140 days 20 to 32 inches—very pale brown loam 32 to 34 inches—white lime- and silica- Characteristics of the Yahoo Soil cemented hardpan over light gray loam Typical profile: 34 to 60 inches—fractured white lime- and 0 to 3 inches—pale brown silt loam silica-cemented hardpan 3 to 9 inches—brown silt loam Depth class: Shallow to a hardpan 9 to 14 inches—very pale brown silt loam Drainage class: Well drained 14 to 34 inches—white lime- and silica- Permeability: Moderate cemented hardpan over very pale brown Available water capacity: 2 to 4 inches fine sandy loam Potential rooting depth: 12 to 20 inches 34 to 60 inches—fractured lime- and silica- Runoff: Very slow cemented hardpan Hazard of water erosion: Slight Depth class: Shallow to a hardpan Hazard of wind erosion: Moderate Drainage class: Well drained Shrink-swell potential: Moderate Permeability: Moderate Contrasting Inclusions Available water capacity: 2 to 4 inches Potential rooting depth: 12 to 20 inches Bahem, Purdam, and Sluka soils on higher lying Runoff: Slow terraces Hazard of water erosion: Slight Use and Management Hazard of wind erosion: Moderate Shrink-swell potential: Moderate Major use: Irrigated cropland Major management factors: Depth to the Contrasting Inclusions hardpan, available water capacity, hazard of Purdam, Roseworth, and Sluka soils on higher wind erosion lying terraces General management considerations: • Most climatically suited crops can be grown if Use and Management irrigation water is provided. • Surface and sprinkler irrigation systems are Major use: Irrigated cropland suited to this soil. Major management factors: Depth to the 132 Soil Survey

hardpan, available water capacity, hazard of 21 to 28 inches—grayish brown clay loam wind erosion 28 to 39 inches—gray clay loam General management considerations: 39 to 54 inches—very dark grayish brown • Most climatically suited crops can be grown if clay irrigation water is provided. 54 to 70 inches—light yellowish brown • Surface and sprinkler irrigation systems are gravelly sandy clay suited to this soil. Depth class: Very deep • Production of irrigated crops is limited by the Drainage class: Moderately well drained shallow rooting depth, low available water Permeability: Slow capacity, and moderate hazard of wind erosion. Available water capacity: 9.5 to 11.5 inches Potential rooting depth: 60 inches or more Interpretive Groups Runoff: Slow Land capability classification: IVe, irrigated, and Hazard of water erosion: Slight VIe, nonirrigated Depth to water table: 48 to 72 inches Frequency of flooding: Rare 148—Zola loam, 0 to 2 percent slopes Shrink-swell potential: High Contrasting Inclusions Composition Tucker soils on lower lying terraces; very deep, Zola soil and similar inclusions—85 percent poorly drained soils that are silt loam over Contrasting inclusions—15 percent silty clay and are in depressional areas of lower lying terraces; very deep sandy loam Setting on terraces and flood plains Position on landscape: Terraces and flood plains Use and Management Elevation: 5,200 to 5,800 feet Average annual precipitation: 12 to 16 inches Major use: Rangeland Average annual air temperature: 41 to 45 Major management factors: None degrees F Dominant vegetation in natural potential plant Frost-free season: 80 to 100 days community: Bluebunch wheatgrass, Wyoming big sagebrush Characteristics of the Zola Soil Interpretive Groups Typical profile: 0 to 5 inches—grayish brown loam Land capability classification: IIIc, nonirrigated 5 to 13 inches—dark grayish brown loam Range site: Loamy, 10 to 13 inch precipitation 13 to 21 inches—brown loam zone 133

Prime Farmland

Prime farmland is one of several kinds of loss of prime farmland to other uses puts important farmland defined by the U.S. pressure on marginal lands, which generally are Department of Agriculture. It is of major more erodible, droughty, and less productive and importance in meeting the Nation’s short- and cannot be easily cultivated. long-range needs for food and fiber. Because the The map units in the survey area that are supply of high-quality farmland is limited, the considered prime farmland are listed in this U.S. Department of Agriculture recognizes that section. This list does not constitute a responsible levels of government, as well as recommendation for a particular land use. On individuals, should encourage and facilitate the some soils included in the list, measures that wise use of our Nation’s prime farmland. overcome a hazard or limitation, such as Prime farmland, as defined by the U.S. flooding, wetness, and droughtiness, are needed. Department of Agriculture, is land that has the Onsite evaluation is needed to determine best combination of physical and chemical whether or not the hazard or limitation has been characteristics for producing food, feed, forage, overcome by corrective measures. The extent of fiber, and oilseed crops and is available for these each listed map unit is shown in table 4. The uses. It could be cultivated land, pasture land, location is shown on the detailed soil maps at the forest land, or other land, but it is not urban or back of this publication. The soil qualities that built-up land or water areas. The soil qualities, affect use and management are described under growing season, and moisture supply are those the heading “Detailed Soil Map Units.” needed for the soil to economically produce The map units that meet the requirements for sustained high yields of crops when proper prime farmland, if irrigated, are: management, including water management, and acceptable farming methods are applied. In 7 Arbidge sandy loam, 1 to 4 percent slopes general, prime farmland has an adequate and 10 Bahem silt loam, 1 to 4 percent slopes dependable supply of moisture from precipitation 17 Barrymore silt loam, 1 to 4 percent slopes or irrigation, a favorable temperature and growing 18 Barrymore-Starbuck complex, 1 to 4 season, acceptable acidity or alkalinity, an percent slopes acceptable salt and sodium content, and few or 19 Bluegulch gravelly loam, 2 to 12 percent no rocks. It is permeable to water and air. It is slopes not excessively erodible or saturated with water 23 Budlewis-Chayson complex, 2 to 6 for long periods, and it either is not frequently percent slopes flooded during the growing season or is 24 Budlewis-Tanner complex, 2 to 6 percent protected from flooding. The slope ranges mainly slopes from 0 to 6 percent. More detailed information 33 Dolman silt loam, 1 to 4 percent slopes about the criteria for prime farmland is available 40 Elijah silt loam, 2 to 4 percent slopes at the local office of the Natural Resources 46 Gosinta silt loam, 0 to 2 percent slopes Conservation Service. 47 Harsan fine sandy loam, 1 to 4 percent About 611,380 acres, or about 39 percent, of slopes the survey area would meet the requirements 50 Hoosegow-Sidlake-Rock outcrop for prime farmland if an adequate and complex, 2 to 15 percent slopes dependable supply of irrigation water were 51 Howcree-Ibola complex, 2 to 6 percent available. slopes A recent trend in land use in some parts 53 Isknat loam, 2 to 8 percent slopes of the survey area has been the loss of some 58 Kecko fine sandy loam, 1 to 4 percent prime farmland to industrial and urban uses. The slopes 134 Soil Survey

59 Kecko fine sandy loam, 4 to 8 percent 101 Rad silt loam, 8 to 12 percent slopes slopes 109 Roseworth silt loam, 1 to 8 percent 67 Minidoka silt loam, 0 to 2 percent slopes slopes 68 Minidoka silt loam, 2 to 4 percent slopes 114 Schnipper silt loam, 2 to 6 percent 75 Owsel silt loam, 0 to 2 percent slopes slopes 76 Owsel silt loam, 2 to 4 percent slopes 122 Shano silt loam, 1 to 4 percent slopes 80 Paniogue loam, 0 to 2 percent slopes 123 Sluka silt loam, 1 to 4 percent slopes 81 Paniogue loam, 2 to 4 percent slopes 132 Taunton sandy loam, 1 to 4 percent 82 Paulville silt loam, 0 to 2 percent slopes slopes 83 Paulville-Idow complex, 1 to 4 percent 133 Taunton sandy loam, 4 to 8 percent slopes slopes 86 Portneuf silt loam, 0 to 2 percent slopes 134 Taunton silt loam, 2 to 4 percent slopes 87 Portneuf silt loam, 2 to 4 percent slopes 135 Tock loam, 1 to 6 percent slopes 88 Portneuf silt loam, 4 to 8 percent slopes 139 Tucker silt loam, 0 to 2 percent slopes 90 Power silt loam, 1 to 4 percent slopes (where drained) 91 Power-McCain complex, 1 to 6 percent 140 Tulch silt loam, 0 to 2 percent slopes slopes 145 Windypoint-Arbidge complex, 1 to 4 93 Purdam silt loam, 1 to 4 percent slopes percent slopes 98 Rad silt loam, 0 to 2 percent slopes 148 Zola loam, 0 to 2 percent slopes (where 99 Rad silt loam, 2 to 4 percent slopes drained) 135

Use and Management of the Soils

This soil survey is an inventory and evaluation Crops and Pasture of the soils in the survey area. It can be used to adjust land uses to the limitations and potentials Prepared by Dal Ames, soil scientist, Natural Resources of natural resources and the environment. Also, it Conservation Service. can help to prevent soil-related failures in land uses. This section provides information on the In preparing a soil survey, soil scientists, management of soils in the survey area for crops conservationists, engineers, and others collect and pasture. The crops and pasture plants best extensive field data about the nature and suited to the soils are identified, the system of behavioral characteristics of the soils. They land capability classification used by the Natural collect data on erosion, droughtiness, flooding, Resources Conservation Service is explained, and other factors that affect various soil uses and and the estimated yields of the main crops and management. Field experience and collected hay and pasture plants are given for each soil. data on soil properties and performance are Planners of management systems for individual used as a basis in predicting soil behavior. fields or farms should consider the detailed Information in this section can be used to plan information given in the section “Detailed Soil the use and management of soils for crops and Map Units.” pasture; as rangeland and woodland; as sites for In 1991 approximately 459,000 acres in the buildings, sanitary facilities, highways and other survey area was used for crops and pasture. Of transportation systems, and parks and other this total, 144,000 acres was used for row crops, recreational facilities; and for wildlife habitat. It 215,000 acres was used for close-grown crops, can be used to identify the potentials and and 100,000 acres was used for alfalfa hay or limitations of each soil for specific land uses and pasture plants. Because livestock operations are to help prevent construction failures caused by a major part of the economy in the area, about unfavorable soil properties. 30 percent of the irrigated land is used for Planners and others using soil survey improved pasture plants, hay, grain, and silage information can evaluate the effect of specific for livestock. The potential for converting land uses on productivity and on the environment rangeland into irrigated cropland depends on the in all or part of the survey area. The survey can availability of irrigation water and the feasibility of help planners to maintain or create a land use delivering the water to the area. Small areas of pattern in harmony with the natural soil. variable soils in Jerome County are isolated by Contractors can use this survey to locate areas of Rock outcrop and presently are not sources of sand and gravel, roadfill, and topsoil. farmed. They can use it to identify areas where bedrock, Major crops include winter wheat, spring wetness, or very firm soil layers can cause wheat, barley, potatoes, dry beans, sugar beets, difficulty in excavation. alfalfa hay, sweet corn, and corn silage. A small Health officials, highway officials, engineers, acreage is used for fruit orchards and specialty and others may also find this survey useful. The seed crops. The warmer climatic conditions on survey can help them plan the safe disposal of the alluvial terraces along the Snake River and wastes and locate sites for pavements, on the side slopes of the Snake River Canyon sidewalks, campgrounds, playgrounds, lawns, allow for a more extensive crop selection. The and trees and shrubs. latest information and suggestions for growing 136 Soil Survey

crops can be obtained from local offices of the cover for wildlife and as well as esthetic value. Cooperative Extension Service and the Natural Information on the design of erosion control Resources Conservation Service. measures for individual soils is available in the Soil erosion reduces crop production and local office of the Natural Resources increases stream pollution. As the surface layer Conservation Service. of the soils erodes, productivity decreases and Good soil tilth, which affects seed germination the sediment deteriorates the quality of water for and water infiltration, is characterized by a municipal and recreational use. Irrigation and granular, porous soil structure. It can be achieved cultivation increase the risk of soil erosion, but through proper farming practices such as suitable conservation practices help to minimize rotating crops, adding organic matter to the soil, the risk. and minimizing tillage. Crops should be grown in Surface and sprinkler irrigation methods are a regular rotation that includes grains and used in the survey area. The surface methods legumes or a mixture of legumes and grasses. used include corrugation, furrow, and border Grain can be grown as a companion crop into systems. Irrigation water management includes which a hay or pasture mixture is seeded. The practices such as installing ditches, lining organic matter content of most of the cropland in pipelines, reorganizing fields, and installing water the area is naturally low. Regular additions of conveyance systems and water control green manure, crop residue, and farm manure structures. The application of irrigation water increase the organic matter content and improve should be based on the available water capacity soil structure and water infiltration. All crop litter and water intake rate of the soils and on the should be returned to the soil. Light applications needs of the crops grown. The soil moisture of farm manure result in uniform crop growth. content should be maintained so that it is neither Returning large amounts of organic residue to too wet nor too dry. Irrigation should wet the root the soil can cause a temporary shortage of zone but not the underlying strata. nitrogen. If properly designed and operated, center- The availability of adequate soil nutrients pivot welling and handiness sprinkler irrigation depends on the previous crops grown and the systems apply water more efficiently than cultural practices used. Farm manure provides surface irrigation methods. Improper system some nitrogen, potash, and phosphate, but design can result in overirrigation and excessive balanced fertilizer is essential to maintaining high runoff and erosion. Proper irrigation water production. All crops respond to nitrogen and management minimizes soil erosion. phosphorus, but some crops also need minor Studies indicate that the topsoil of many soils elements such as zinc. Nitrogen can be applied in the survey area has been eroded as a result of with irrigation water, but excessive fertilization irrigation. The risk of erosion is highest in areas can result in serious pollution of surface water of surface irrigated row crops such as beans, and groundwater. Sulfur deficiencies are rare in corn, and potatoes. Conservation tillage to areas irrigated with water from the Snake River. maintain crop residue on the surface can reduce Soil tests are needed to determine specific soil loss by as much as 50 to 90 percent. fertilizer needs. The Cooperative Extension Many of the soils used as cropland are Service can help to determine the kind and subject to a high hazard of wind erosion. Special amount of fertilizer needed. practices are needed to protect these soils.. The Subsoiling can improve yields on soils that risk of wind erosion is highest between February have a restrictive layer by increasing the effective and June. Conservation tillage practices that rooting depth, improving internal water infiltration maintain a protective cover on the soil surface and drainage, and reducing runoff. Subsoiling are critical during this period. only in areas where crop residue is maintained Wind erosion can occur when the soil is dry on the surface helps to protect the soil. and is barren of vegetation or plant residue. Subsoiling should penetrate the compacted layer, Cropping systems that maintain plant cover or and it should be done across the slope. Shallow surface mulch or that keep the surface rough soils and soils that allow moisture to escape through minimum tillage or no-till methods through deep substrata should not be subsoiled. reduce the risk of wind erosion. Windbreaks of Excess salts generally reduce crop yields. adapted trees and shrubs and grass barriers Because soil reclamation is difficult, time- also reduce the risk of wind erosion and provide consuming, and expensive, salt-tolerant crops Jerome-Twin Falls, Idaho 137

should be considered for use in areas of excess productivity of a given soil compared with that of salts. Specific information can be obtained from other soils, however, is not likely to change. the local offices of the Natural Resources Crops other than those shown in the table are Conservation Service or the Cooperative grown in the survey area, but estimated yields Extension Service. are not listed because the acreage of such crops Practices needed to produce a variety of high- is small. The local office of the Natural quality forage plants on pastureland include use Resources Conservation Service or of the of proper stocking rates, good soil and irrigation Cooperative Extension Service can provide water management, and weed and rodent information about the management and control. Cross-fencing and rotation grazing are productivity of the soils for those crops. needed to allow for periods of regrowth. During Land Capability Classification the grazing season, pastures should be grazed and irrigated to meet the needs of the plant Land capability classification shows, in a grown. Grazing should be deferred while the general way, the suitability of soils for most kinds pastures are irrigated. of field crops. Crops that require special management are excluded. The soils are Yields per Acre grouped according to their limitations for field The average yields per acre that can be crops, the risk of damage if they are used for expected of the principal crops under a high level crops, and the way they respond to of management are shown in table 5. In any management. The criteria used in grouping the given year, yields may be higher or lower than soils do not include major and generally those indicated in the table because of variations expensive landforming that would change slope, in rainfall and other climatic factors. The land depth, or other characteristics of the soils, nor do capability classification of each map unit also is they include possible but unlikely major shown in the table. reclamation projects. Capability classification is The yields are based mainly on the not a substitute for interpretations designed to experience and records of farmers, show suitability and limitations of groups of soils conservationists, and extension agents. Available for rangeland, for woodland, and for engineering yield data from nearby counties and results of purposes. field trials and demonstrations are also In the capability system (14), soils are considered. generally grouped at three levels-capability class, The management needed to obtain the subclass, and unit. Only class and subclass are indicated yields of the various crops depends on used in this survey. the kind of soil and the crop. Management can Capability classes, the broadest groups, are include drainage, erosion control, and protection designated by numerals I through VIII. The from flooding; the proper planting and seeding numerals indicate progressively greater rates; suitable high-yielding crop varieties; limitations and narrower choices for practical use. appropriate and timely tillage; control of weeds, The classes are defined as follows: plant diseases, and harmful insects; favorable Class I soils have few limitations that restrict soil reaction and optimum levels of nitrogen, their use. phosphorus, potassium, and trace elements for Class II soils have moderate limitations that each crop; effective use of crop residue, reduce the choice of plants or that require barnyard manure, and green manure crops; and moderate conservation practices. harvesting that ensures the smallest possible Class III soils have severe limitations that loss. reduce the choice of plants or that require For yields of irrigated crops, it is assumed that special conservation practices, or both. the irrigation system is adapted to the soils and Class IV soils have very severe limitations that to the crops grown, that good-quality irrigation reduce the choice of plants or that require very water is uniformly applied as needed, and that careful management, or both. tillage is kept to a minimum. Class V soils are not likely to erode but have The estimated yields reflect the productive other limitations, impractical to remove, that limit capacity of each soil for each of the principal their use. crops. Yields are likely to increase as new Class VI soils have severe limitations that production technology is developed. The make them generally unsuitable for cultivation. 138 Soil Survey

Class VII soils have very severe limitations Typically, livestock are fed ranch-raised alfalfa that make them unsuitable for cultivation. and grass hay from mid-November until the Class VIII soils and miscellaneous areas have range is suitable for grazing in April. Crop limitations that nearly preclude their use for aftermath provides a significant amount of forage commercial crop production. through fall and into winter. During open winters, Capability subclasses are soil groups within livestock can graze in pastures of crested one class. They are designated by adding a wheatgrass and only supplements are needed small letter, e, w, s, or c, to the class numeral, for until spring. example, IIe. The letter e shows that the main The rangeland is suitable for grazing early in hazard is the risk of erosion unless close- April in the lower lying, northern areas and early growing plant cover is maintained; w shows that in June in the higher lying, southern areas. water in or on the soil interferes with plant growth Rotation grazing systems that include periods of or cultivation (in some soils the wetness can be rest are common in the drier, lower lying areas, partly corrected by artificial drainage); s shows and deferred rotation systems are common in that the soil is limited mainly because it is areas used in summer. About 25 percent of the shallow, droughty, or stony; and c, used in only livestock graze in areas of rangeland outside the some parts of the United States, shows that the survey area in summer. chief limitation is climate that is very cold or very Historically, rangeland consisted of a mixed dry. stand of bunchgrasses, forbs, and shrubs. Class V contains only the subclasses Climatic factors dictated the diversity of the plant indicated by w, s, or c because the soils in class community, with lower lying terraces supporting V are subject to little or no erosion. They have Thurber needlegrass and Wyoming big other limitations that restrict their use to pasture, sagebrush and higher lying uplands supporting rangeland, woodland, wildlife habitat, or mainly bluebunch wheatgrass, Idaho fescue, and recreation. mountain big sagebrush. Overgrazing reduced or Capability units are soil groups within a eliminated many of the perennial plants, and subclass. The soils in a capability unit are annuals and shrubs increased. Because forage enough alike to be suited to the same crops and production was reduced, rangeland seeding pasture plants, to require similar management, became an economic necessity. Presently, native and to have similar productivity. vegetation exists only in isolated areas protected The capability classification of each map unit from grazing. Suitable management practices for is given in the section “Detailed Soil Map Units.” specific range sites can be used to increase rangeland productivity. Rangeland In areas that have similar climate and Prepared by Brian Miller, district conservationist, Natural topography, differences in the kind and amount of Resources Conservation Service, Gooding, Idaho. vegetation produced on rangeland are closely related to the kind of soil. Effective management Approximately 1,000,000 acres, or about 65 is based on the relationship between soils and percent, of the soil survey area is rangeland. Of vegetation and water. this, about 60 percent is managed by the Bureau Table 6 shows, for each soil, the range site; of Land Management, 35 percent by private the total annual production of vegetation in ranchers, and 5 percent by the Department of favorable, normal, and unfavorable years; the Lands, State of Idaho. characteristic vegetation; and the average Commercial livestock enterprises, including percentage of each species. Only those soils that cow-calf operations, dairies, feedlots, and are used as rangeland or are suited to use as purebred cattle and sheep operations, account rangeland are listed. Explanation of the column for almost one-half of the agricultural income in headings in the follows. the survey area. Ranch sizes vary, but they A range site is a distinctive kind of rangeland generally consist of 2,000 to 5,000 acres of that produces a characteristic natural plant private land and grazing privileges on Federal community that differs from natural plant and State land. Grazing occurs in spring, communities on other range sites in kind, summer, and fall. In mid-December, or earlier if amount, and proportion of range plants. The grazeable rangeland forage is depleted, livestock relationship between soils and vegetation was are moved to pastures, stubble fields, or drylots. ascertained during this survey; thus, range sites Jerome-Twin Falls, Idaho 139

generally can be determined directly from the soil wildlife and for providing wildlife habitat, water, map. Soil properties that affect moisture supply watershed production, recreational use, and and plant nutrients have the greatest influence on other uses. Sometimes rangeland managed the productivity of range plants. Soil reaction, salt below its potential meets grazing needs, provides content, and a seasonal water table are also wildlife habitat, protects soil and water resources, important. and meets other management objectives. Total annual production is the amount of A planned grazing system increases forage vegetation that can be expected to grow annually production by allowing forage species to produce on rangeland. It includes all vegetation, including nutrients for growth and maintenance. Plants grasses, forbs, and the current year’s growth of need adequate spring growth before grazing leaves, twigs, and fruit of woody plants. It does begins. Fencing, salting away from water and not include the increase in stem diameter of meadows, and constructing livestock trails and trees and shrubs, the production from previous upland water developments helps to achieve years, or the underground growth. It is expressed uniform use of forage by livestock. Specific soil in pounds per acre of air-dry vegetation for and site characteristics should be considered to favorable, normal, and unfavorable years. In a determine suitable practices. Deferred grazing or favorable year, the amount and distribution of noncontinuous grazing allows plants to complete precipitation and the temperatures make growing their growth cycle and replenish their reserve of conditions substantially better than average. In a carbohydrates. In areas where proper grazing normal year, growing conditions are about management alone cannot restore the vegetation average. In an unfavorable year, growing to its potential within a reasonable period of time, conditions are well below average, generally brush control and range seeding should be because of low available soil moisture. considered. Prescribed burning and chemical or Production is expressed in pounds per acre of mechanical treatment can be used to control air-dry vegetation. Yields are adjusted to a infestations of unwanted shrubs, but use of these common percent of air-dry moisture content. The methods can also increase the risk of erosion. relationship of green weight to air-dry weight Annual plant competition and low rainfall can varies according to such factors as exposure, result in seeding failure. Seedbeds should be amount of shade, recent rains, and prepared by disking and fallowing one season unseasonable dry periods. before seeding. The seedbed should be firm and Characteristic vegetation is the grasses, forbs, free of weeds before seeding late in fall. New and shrubs that make up most of the natural seedings should not be grazed during the entire potential plant community. It is listed by common first year and the growing season of the next name for each soil. Under composition, the year. expected percentage of the total annual Sound range management based on the production is given for each species making up information in this soil survey and other the characteristic vegetation. The amount that rangeland inventories can maintain or improve can be used as forage depends on the kinds of forage production. grazing animals and the grazing season. Range management requires a knowledge of Windbreaks and Environmental the kinds of soil and of the natural potential plant Plantings community. It also requires an evaluation of the present range condition. Range condition is Windbreaks protect livestock, buildings, and determined by comparing the present plant yards from wind and snow. They also protect fruit community with the natural potential plant trees and gardens, and they furnish habitat for community on a particular range site. The more wildlife. Several rows of low- and high-growing closely the existing community resembles the broadleaf and coniferous trees and shrubs potential community, the better the range generally provide the most protection however condition. Range condition is an ecological rating grass barriers may be effective in controlling only. It does not have a specific meaning for a erosion in field windbreak situations. given use. Field windbreaks are narrow plantings made at The objective in range management is to right angles to the prevailing wind and at specific manipulate the use of rangeland to maintain its intervals across the field. The interval depends on potential for producing forage for livestock and the erodibility of the soil. Field windbreaks protect 140 Soil Survey

cropland and crops from wind, help to keep snow in the survey area to the specific wildlife species on the fields, and provide food and cover for and their activities. Wildlife in an area typically is wildlife. related to the vegetation that is present. Environmental plantings help to beautify and Vegetation is closely related to the soil and its screen houses and other buildings and to abate capability to produce herbaceous and woody noise. The plants, mostly evergreen shrubs and plants. trees, are closely spaced. To ensure plant The survey area supports a variety of fish and survival, a healthy planting stock of suitable wildlife, including mammals, birds, reptiles, and species should be planted properly on a well amphibians. Migratory wildlife, many of which are prepared site and maintained in good condition. avian species, use the area seasonally. The wide Table 7 shows the height that locally grown array of fish and wildlife in the area are trees and shrubs are expected to reach in 20 supported by the variety of habitats present. The years on various soils. The estimates in the table mountains, terraces, bottom land, and are based on measurements and observation of drainageways and the associated soils, the established plantings that have been given precipitation, the land uses, and the topography adequate care. They can be used as a guide in provide diverse habitats. planning windbreaks and screens. Additional The dominant vegetation at the higher information on planning windbreaks and screens elevations includes big sagebrush, low and planting and caring for trees and shrubs can sagebrush, Idaho fescue, and bluebunch be obtained from the local office of the Natural wheatgrass. Smaller areas of aspen, Resources Conservation Service or of the serviceberry, bitterbrush, and snowberry Cooperative Extension Service or from a are scattered throughout the higher elevations. commercial nursery. The vegetation at the intermediate elevations is dominantly big sagebrush, bitterbrush, Recreation rabbitbrush, Idaho fescue, and wheatgrasses. Prepared by Dal Ames, soil scientist, Natural Agricultural activities, mainly crop production, Resources Conservation Service. occur throughout these areas and add to the diversity of the habitat. The deep canyons, open deserts, and rolling Springs and drainageways, although small uplands in this survey area provide year-round in total acreage, are key to wildlife diversity in the outdoor opportunities for hunters, fishermen, survey area. These riparian areas occur as linear water and winter sports enthusiasts, picnickers, ribbons, frequently extending through several hikers, campers, sightseers, and students of general soil map units. Vegetation associated with photography and nature. Natural features that these areas includes willow, cottonwood, encourage outdoor use include the canyons of dogwood, alder, aspen, and sedges and other the Snake River and Salmon Falls Creek; the water-tolerant grasses. Twin, Shoshone, Pillar, and Auger Waterfalls on the Snake River; the geologic formations of Ungulates Balanced Rock; the Hagerman Fossil Beds National Monument; the South Hills; and the Ungulates, dominantly mule deer and erosional remnants of the Bonneville Flood as antelope, are the largest and most easily seen at Devils Corral and Dry Cataracts National recognized animals in the survey area. Small Natural Landmark. populations of whitetail deer and elk also are Urban recreational facilities, such as parks, present in the area. ballfields, playgrounds, swimming pools, tennis Mule deer are throughout the area in habitat courts, and golf courses are in or around the ranging from the high mountainous areas to the major population centers. canyonlands along the Snake River. Mule deer populations are dependent on winter and Wildlife summer habitat. Areas that support mountain brush plant communities comprised of Prepared by Frank Fink, wildlife biologist, Natural sagebrush, bitterbrush, rabbitbrush, snowberry, Resources Conservation Service, from data provided by serviceberry, and aspen are used by mule deer biologists of the Idaho Department of Fish and Game. in summer. Although mule deer can be seen This section relates the general soil map units throughout the survey area, the largest Jerome-Twin Falls, Idaho 141

populations in summer are in the south and Sage grouse populations are highest in the south-central parts in areas associated with south and south-central parts of the survey area. general soil map units 7, 9, 11, 12, 14, 15, 16, These areas are characterized by a plant 17, 18, 19, and 20. community that supports dominantly sagebrush, Winter habitat for mule deer is characterized grasses, and forbs. General soil map units 7, 9, by sagebrush and bitterbrush rangeland at the 11, 12, 14, 15, 16, 17, 18, and 20 typically are lower elevations and along riparian areas and associated with plant communities suitable for canyons. The south-central part associated with sage grouse. Sage grouse migrate through these general soil map units 7, 8, 9, and 11 provides areas inhabiting the more open grass and forb wintering areas for deer. General soil map unit plant communities in summer and relying on 13, which is associated with the Snake River and areas that support dominantly sagebrush during Salmon Falls Creek, also provides critical the rest of the year. Because sage grouse rely on wintering areas. areas that support sagebrush and grasses, they Mule deer populations are also increasing are extremely vulnerable to land use in the agricultural and rangeland areas management practices. associated with general soil map units 2, 6, and Wild turkeys have been introduced into the 10. survey area, and they sustain a small resident Antelope are throughout the survey area. The population in general soil map unit 13. These largest populations are in the south and south- birds inhabit the Snake River Canyon, in the central parts associated with rangeland and vicinity of the Niagara Springs Wildlife scattered agricultural areas. General soil map Management Area. A small population is also in units 9, 14, 15, 16, 17, and 18 offer the highest the riparian areas along Big Cottonwood Creek, quality habitat. Flat to rolling areas support in the west-central part of the survey area. dominantly grasses and sagebrush. Antelope California quail inhabit the Snake River also roam in the northern parts of the survey corridor from Twin Falls downstream along area in areas associated with general soil map Salmon Falls Creek and Rock Creek. General units, 5, 6, and 10. soil map unit 13 provides the best habitat for Elk are rare in the survey area. During harsh quail. Habitat suitable for quail is in steep winters, they sometimes migrate into Jerome canyons and on riparian bottom land and County from the north in areas associated with associated agricultural areas. general soil map units 2, 5, 6, and 10. Chukar populations in the area are small. The Occasionally elk are seen in the extreme largest number is along Salmon Falls Creek in southern parts of Twin Falls County in areas areas associated with general soil map unit 13. associated with general soil map units 12, 15, The rocky slopes, steep terrain, and adjacent 16, and 18. riparian areas provide habitat for chukar. The quality of the habitat is dependent on the Avians condition of the riparian areas and on adequate water supplies. Common upland game birds in the survey area Many nongame birds are in the survey area. include pheasants, gray partridge, California These include kingfishers, woodpeckers, larks, quail, and sage grouse. Small populations of swallows, magpies, crows, chickadees, wrens, turkey and chukar also inhabit the area. thrashers, thrushes, flycatchers, starlings, vireos, Pheasant and gray partridge are in agricultural warblers, finches, blackbirds, tanagers, and areas associated with general soil map units 1, sparrows. The Snake River corridor and the 2, 3, 4, 5, 7, 8, 10, and 11. The woody vegetation Salmon Falls Creek and Rock Creek areas in these map units and the riparian areas provide diverse habitat for nongame avian associated with general soil map unit 13 provide populations. The intermittent and permanent habitat in winter. Pheasant and partridge tributary creeks of the Snake River and the populations are dependent on the availability of riparian areas throughout Jerome and Twin Falls undisturbed nesting cover and adequate woody Counties also contribute to the habitat. Poor vegetation in harsh winters. Loss of undisturbed management of these areas can restrict the herbaceous plants associated with irregularly growth of diverse plant communities and thus shaped areas in the corners of fields and along reduce the bird populations. The number of irrigation canals and ditches have resulted in a nongame bird species in an area provides an low rate of survival in winter. indicator of the environmental health of a region. 142 Soil Survey

Waterfowl although small, is highest in areas with large populations of mule deer. Waterfowl are concentrated along streams, rivers, and reservoirs in the survey area. Fisheries Waterfowl species include Canada geese, Fisheries in the survey area are limited to mallard, gadwall, widgeon, teal, goldeneye, stream and reservoir habitat. Several reservoirs canvasback, ringneck, redhead, pintail, and in the area provide fishing opportunities for local scaup. and state residents. Wilson Lake, Cedar Creek, The Hagerman and Niagara Springs Wildlife Murtaugh Lake, and Salmon Falls Creek Management Areas along the Snake River Reservoirs provide the most diverse fish provide critical breeding and wintering areas for populations in the area. All of these except large numbers of Canada geese and mallards. Murtaugh Lake are stocked with rainbow trout. Waterfowl populations in other areas of Twin Salmon Falls Creek Reservoir has the most Falls and Jerome Counties associated with diverse game fish populations. Species include creeks, canals, wetlands, and reservoirs usually walleye, rainbow and brown trout, kokanee, small are limited in value because of poor quality mouth bass, perch, and black crappie. nesting and rearing areas. Stream and creek fisheries are in Snake Trumpeter swans are being introduced into River, Salmon Falls Creek, Rock Creek, and areas from eastern Idaho to the lower reaches of other tributaries that have a permanent the Snake River. This is an effort by State and waterflow. Fish species associated with the Federal agencies to reduce the high mortality streams and creeks include rainbow trout and rate of the swans by expanding their winter brown trout. Shoshone sculpin, listed by Idaho as range. a species of special concern, also inhabit springs Raptors in the survey area. White sturgeon inhabit the Snake River from Shoshone Falls downstream. Hawks, eagles, and owls are throughout the The quality of the stream and creek fisheries survey area. The canyons associated with the is closely tied to the quality of the surrounding Snake River, Salmon Falls Creek, and Rock riparian areas. Poor management of the riparian Creek offer many exposed cliffs suitable as areas has lead to poor quality water and habitat. nesting areas for a variety of species. The Snake Development in spring has depleted natural River Canyon also provides winter habitat for spawning areas. Heavy sedimentation and bald eagles and rough-legged hawks. Species nutrient loads have degraded the fish that use the survey area include golden eagle, resource. Some portions of the rivers and bald eagle, prairie falcon, red-tailed hawk, creeks do not meet the Idaho designated ferruginous hawk, rough-legged hawk, northern beneficial use of salmonid spawning and cold harrier, kestrel, burrowing owl, short-eared owl, water biota. great horned owl, and a few peregrine falcon. Threatened and Endangered Species Furbearers Two threatened or endangered species, the Furbearers such as otter, beaver, mink, bald eagle and peregrine falcon, are known to raccoon, and muskrat live in and adjacent to the use the survey area at certain times of the year, major streams and creeks in the survey area. but they are not known to nest in the area. In General soil map unit 13, which is associated winter bald eagles feed in areas associated with with the Snake River and Salmon Falls Creek, lakes, streams, and creeks along the Snake provides the most diverse habitat for these River. Areas of general soil map unit 13 provide furbearers. Small creeks, canals, and reservoirs most of this winter habitat. Peregrine falcon use throughout the area also provide the diverse areas associated with the canyons of the Snake habitat needed for small populations of the River and Salmon Falls Creek. These areas have furbearers. potential as nesting areas for falcon. All general Coyote, red fox, and badger are throughout the soil map units except the mountainous units survey. Bobcats and lions have limited range, but provide potential habitat for peregrine falcon. they typically are in areas that have not been The fish and wildlife resources in the survey disturbed by humans. The population of lions, area are largely determined by the suitability of Jerome-Twin Falls, Idaho 143

the habitat, including the supply of food, the ratings in this section. During the fieldwork for amount of cover, and the availability of water. this soil survey, determinations were made about Habitats differ in their capacity to provide these grain-size distribution, liquid limit, plasticity index, essential ingredients. Some deficiencies are the soil reaction, depth to bedrock, hardness of result of characteristics of the soils and others bedrock within 5 or 6 feet of the surface, soil are the result of management practices. The wetness, depth to a seasonal high water table, soils can be managed to improve habitat for fish slope, likelihood of flooding, natural soil structure and wildlife, but the other uses of the soils should aggregation, and soil density. Data were be considered when determining proper collected about kinds of clay minerals, management practices. mineralogy of the sand and silt fractions, and the Soils affect the kind and amount of kinds of adsorbed cations. Estimates were made vegetation available as food and cover for fish for erodibility, permeability, corrosivity, shrink- and wildlife. Soils also affect the construction of swell potential, available water capacity, and water impoundments and other engineering other behavioral characteristics affecting practices. Wildlife habitat can be created or engineering uses. improved by planting appropriate vegetation, This information can be used to evaluate the maintaining the existing vegetation, or potential of areas for residential, commercial, promoting natural establishment of desirable industrial, and recreational uses; make plants. preliminary estimates of construction conditions; evaluate alternative routes for roads, streets, Engineering highways, pipelines, and underground cables; This section provides information for planning evaluate alternative sites for sanitary landfills, land uses related to urban development and to septic tank absorption fields, and sewage water management. Soils are rated for various lagoons; plan detailed onsite investigations of uses, and the most limiting features are soils and geology; locate potential sources of identified. Ratings are given for building site gravel, sand, earthfill, and topsoil; plan drainage development, sanitary facilities, construction systems, irrigation systems, ponds, terraces, and materials, and water management. The ratings other structures for soil and water conservation; are based on observed performance of the soils and predict performance of proposed small and on the estimated data and test data in the structures and pavements by comparing the “Soil Properties” section. performance of existing similar structures on the Information in this section is intended for land same or similar soils. use planning, for evaluating land use The information in the tables, along with the alternatives, and for planning site investigations soil maps, the soil descriptions, and other data prior to design and construction. The information, provided in this survey, can be used to make however, has limitations. For example, estimates additional interpretations. and other data generally apply only to that part of Some of the terms used in this soil survey the soil within a depth of 5 or 6 feet. Because of have a special meaning in soil science and are the map scale, small areas of different soils may defined in the Glossary. be included within the mapped areas of a Building Site Development specific soil. The information is not site specific and does Table 8 shows the degree and kind of soil not eliminate the need for onsite investigation of limitations that affect shallow excavations, the soils or for testing and analysis by personnel dwellings with and without basements, small experienced in the design and construction of commercial buildings, local roads and streets, engineering works. and lawns and landscaping. The limitations are Government ordinances and regulations that considered slight if soil properties and site restrict certain land uses or impose specific features are generally favorable for the indicated design criteria were not considered in preparing use and limitations are minor and easily the information in this section. Local ordinances overcome; moderate if soil properties or site and regulations should be considered in planning, features are not favorable for the indicated use in site selection, and in design. and special planning, design, or maintenance is Soil properties, site features, and observed needed to overcome or minimize the limitations; performance were considered in determining the and severe if soil properties or site features are 144 Soil Survey

so unfavorable or so difficult to overcome that Lawns and landscaping require soils on which special design, significant increases in turf and ornamental trees and shrubs can be construction costs, and possibly increased established and maintained. The ratings are maintenance are required. Special feasibility based on soil properties, site features, and studies may be required where the soil observed performance of the soils. Soil reaction, limitations are severe. a high water table, depth to bedrock or to a Shallow excavations are trenches or holes cemented pan, the available water capacity in dug to a maximum depth of 5 or 6 feet for the upper 40 inches, and the content of salts, basements, graves, utility lines, open ditches, sodium, and sulfidic materials affect plant growth. and other purposes. The ratings are based on Flooding, wetness, slope, stoniness, and the soil properties, site features, and observed amount of sand, clay, or organic matter in the performance of the soils. The ease of digging, surface layer affect trafficability after vegetation is filling, and compacting is affected by the depth to established. bedrock, a cemented pan, or a very firm dense Sanitary Facilities layer; stone content; soil texture; and slope. The time of the year that excavations can be made is Table 9 shows the degree and kind of soil affected by the depth to a seasonal high water limitations that affect septic tank absorption table and the susceptibility of the soil to flooding. fields, sewage lagoons, and sanitary landfills. The resistance of the excavation walls or banks The limitations are considered slight if soil to sloughing or caving is affected by soil texture properties and site features are generally and depth to the water table. favorable for the indicated use and limitations are Dwellings and small commercial buildings are minor and easily overcome; moderate if soil structures built on shallow foundations on properties or site features are not favorable for undisturbed soil. The load limit is the same as the indicated use and special planning, design, that for single-family dwellings no higher than or maintenance is needed to overcome or three stories. Ratings are made for small minimize the limitations; and severe if soil commercial buildings without basements, for properties or site features are so unfavorable or dwellings with basements, and for dwellings so difficult to overcome that special design, without basements. The ratings are based on soil significant increases in construction costs, and properties, site features, and observed possibly increased maintenance are required. performance of the soils. A high water table, The table also shows the suitability of the soils flooding, shrinking and swelling, and organic for use as daily cover for landfill. A rating of good layers can cause the movement of footings. A indicates that soil properties and site features high water table, depth to bedrock or to a are favorable for the use and good performance cemented pan, large stones, slope, and flooding and low maintenance can be expected; fair affect the ease of excavation and construction. indicates that soil properties and site features Landscaping and grading that require cuts and are moderately favorable for the use and one or fills of more than 5 or 6 feet are not considered. more soil properties or site features make the Local roads and streets have an all-weather soil less desirable than the soils rated good; and surface and carry automobile and light truck poor indicates that one or more soil properties or traffic all year. They have a subgrade of cut or fill site features are unfavorable for the use and soil material; a base of gravel, crushed rock, or overcoming the unfavorable properties requires stabilized soil material; and a flexible or rigid special design, extra maintenance, or costly surface. Cuts and fills are generally limited to alteration. less than 6 feet. The ratings are based on soil Septic tank absorption fields are areas in properties, site features, and observed which effluent from a septic tank is distributed performance of the soils. Depth to bedrock or to into the soil through subsurface tiles or a cemented pan, a high water table, flooding, perforated pipe. Only that part of the soil large stones, and slope affect the ease of between depths of 24 and 72 inches is evaluated. excavating and grading. Soil strength (as inferred The ratings are based on soil properties, site from the engineering classification of the soil), features, and observed performance of the soils. shrink-swell potential, frost action potential, and Permeability, a high water table, depth to bedrock depth to a high water table affect the traffic- or to a cemented pan, and flooding affect supporting capacity. absorption of the effluent. Large stones and Jerome-Twin Falls, Idaho 145

bedrock or a cemented pan interfere with on the surface of the soil. The waste is spread, installation. compacted, and covered daily with a thin layer of Unsatisfactory performance of septic tank soil from a source away from the site. absorption fields, including excessively slow Both types of landfill must be able to bear absorption of effluent, surfacing of effluent, and heavy vehicular traffic. Both types involve a risk hillside seepage, can affect public health. Ground of ground-water pollution. Ease of excavation water can be polluted if highly permeable sand and revegetation should be considered. and gravel or fractured bedrock is less than 4 The ratings in the table are based on soil feet below the base of the absorption field, if properties, site features, and observed slope is excessive, or if the water table is near performance of the soils. Permeability, depth to the surface. There must be unsaturated soil bedrock or to a cemented pan, a high water material beneath the absorption field to filter the table, slope, and flooding affect both types of effluent effectively. Many local ordinances require landfill. Texture, stones and boulders, highly that this material be of a certain thickness. organic layers, soil reaction, and content of salts Sewage lagoons are shallow ponds and sodium affect trench landfills. Unless constructed to hold sewage while aerobic otherwise stated, the ratings apply only to that bacteria decompose the solid and liquid wastes. part of the soil within a depth of about 6 feet. For Lagoons should have a nearly level floor deeper trenches, a limitation rated slight or surrounded by cut slopes or embankments of moderate may not be valid. Onsite investigation compacted soil. Lagoons generally are designed is needed. to hold the sewage within a depth of 2 to 5 feet. Daily cover for landfill is the soil material that Nearly impervious soil material for the lagoon is used to cover compacted solid waste in an floor and sides is required to minimize seepage area sanitary landfill. The soil material is and contamination of ground water. obtained offsite, transported to the landfill, and The table gives ratings for the natural soil that spread over the waste. makes up the lagoon floor. The surface layer and, Soil texture, wetness, coarse fragments, and generally, 1 or 2 feet of soil material below the slope affect the ease of removing and spreading surface layer are excavated to provide material the material during wet and dry periods. Loamy for the embankments. The ratings are based on or silty soils that are free of large stones or soil properties, site features, and observed excess gravel are the best cover for a landfill. performance of the soils. Considered in the Clayey soils are sticky or cloddy and are difficult ratings are slope, permeability, a high water to spread; sandy soils are subject to wind table, depth to bedrock or to a cemented pan, erosion. flooding, large stones, and content of organic After soil material has been removed, the soil matter. material remaining in the borrow area must be Excessive seepage resulting from rapid thick enough over bedrock, a cemented pan, or permeability in the soil or a water table that is the water table to permit revegetation. The soil high enough to raise the level of sewage in the material used as the final cover for a landfill lagoon causes a lagoon to function should be suitable for plants. The surface layer unsatisfactorily. Pollution results if seepage is generally has the best workability, more organic excessive or if floodwater overtops the lagoon. A matter, and the best potential for plants. Material high content of organic matter is detrimental to from the surface layer should be stockpiled for proper functioning of the lagoon because it use as the final cover. inhibits aerobic activity. Slope, bedrock, and Construction Materials cemented pans can cause construction problems, and large stones can hinder Table 10 gives information about the soils as a compaction of the lagoon floor. source of roadfill, sand, gravel, and topsoil. The Sanitary landfills are areas where solid waste soils are rated good, fair, or poor as a source of is disposed of by burying it in soil. There are two roadfill and topsoil. They are rated as a probable types of landfill—trench and area. In a trench or improbable source of sand and gravel. The landfill, the waste is placed in a trench. It is ratings are based on soil properties and site spread, compacted, and covered daily with a thin features that affect the removal of the soil and its layer of soil excavated at the site. In an area use as construction material. Normal landfill, the waste is placed in successive layers compaction, minor processing, and other 146 Soil Survey

standard construction practices are assumed. The properties used to evaluate the soil as a Each soil is evaluated to a depth of 5 or 6 feet. source of sand or gravel are gradation of grain Roadfill is soil material that is excavated in sizes (as indicated by the engineering one place and used in road embankments in classification of the soil), the thickness of suitable another place. In this table, the soils are rated as material, and the content of rock fragments. a source of roadfill for low embankments, Kinds of rock, acidity, and stratification are given generally less than 6 feet high and less exacting in the soil series descriptions. Gradation of grain in design than higher embankments. sizes is given in the table on engineering index The ratings are for the soil material below the properties. surface layer to a depth of 5 or 6 feet. It is A soil rated as a probable source has a layer assumed that soil layers will be mixed during of clean sand or gravel or a layer of sand or excavating and spreading. Many soils have gravel that is up to 12 percent silty fines. This layers of contrasting suitability within their profile. material must be at least 3 feet thick and less The table showing engineering index properties than 50 percent, by weight, large stones. All provides detailed information about each soil other soils are rated as an improbable source. layer. This information can help to determine the Coarse fragments of soft bedrock, such as shale suitability of each layer for use as roadfill. The and siltstone, are not considered to be sand and performance of soil after it is stabilized with lime gravel. or cement is not considered in the ratings. Topsoil is used to cover an area so that The ratings are based on soil properties, site vegetation can be established and maintained. features, and observed performance of the soils. The upper 40 inches of a soil is evaluated for use The thickness of suitable material is a major as topsoil. Also evaluated is the reclamation consideration. The ease of excavation is affected potential of the borrow area. by large stones, a high water table, and slope. Plant growth is affected by toxic material and How well the soil performs in place after it has by such properties as soil reaction, available been compacted and drained is determined by water capacity, and fertility. The ease of its strength (as inferred from the engineering excavating, loading, and spreading is affected by classification of the soil) and shrink-swell rock fragments, slope, a water table, soil texture, potential. and thickness of suitable material. Reclamation Soils rated good contain significant amounts of the borrow area is affected by slope, a water of sand or gravel or both. They have at least 5 table, rock fragments, bedrock, and toxic feet of suitable material, a low shrink-swell material. potential, few cobbles and stones, and slopes of Soils rated good have friable, loamy material 15 percent or less. Depth to the water table is to a depth of at least 40 inches. They are free of more than 3 feet. Soils rated fair are more than stones and cobbles, have little or no gravel, and 35 percent silt- and clay-sized particles and have have slopes of less than 8 percent. They are low a plasticity index of less than 10. They have a in content of soluble salts, are naturally fertile or moderate shrink-swell potential, slopes of 15 to respond well to fertilizer, and are not so wet that 25 percent, or many stones. Depth to the water excavation is difficult. table is 1 to 3 feet. Soils rated poor have a Soils rated fair are sandy soils, loamy soils plasticity index of more than 10, a high shrink- that have a relatively high content of clay, soils swell potential, many stones, or slopes of more that have only 20 to 40 inches of suitable than 25 percent. They are wet and have a water material, soils that have an appreciable amount table at a depth of less than 1 foot. They may of gravel, stones, or soluble salts, or soils that have layers of suitable material, but the material have slopes of 8 to 15 percent. The soils are not is less than 3 feet thick. so wet that excavation is difficult. Sand and gravel are natural aggregates Soils rated poor are very sandy or clayey, suitable for commercial use with a minimum of have less than 20 inches of suitable material, processing. They are used in many kinds of have a large amount of gravel, stones, or soluble construction. Specifications for each use vary salts, have slopes of more than 15 percent, or widely. In the table, only the probability of finding have a seasonal high water table at or near the material in suitable quantity is evaluated. The surface. suitability of the material for specific purposes is The surface layer of most soils is generally not evaluated, nor are factors that affect preferred for topsoil because of its organic matter excavation of the material. content. Organic matter greatly increases the Jerome-Twin Falls, Idaho 147

absorption and retention of moisture and nutrients properties to a depth even greater than the height for plant growth. of the embankment can affect performance and safety of the embankment. Generally, deeper Water Management onsite investigation is needed to determine these Table 11 gives information on the soil properties. properties and site features that affect water Soil material in embankments must be management. The degree and kind of soil resistant to seepage, piping, and erosion limitations are given for pond reservoir areas and and have favorable compaction characteristics. embankments, dikes, and levees. The limitations Unfavorable features include less than 5 are considered slight if soil properties and site feet of suitable material and a high content features are generally favorable for the indicated of stones or boulders, organic matter, or salts use and limitations are minor and are easily or sodium. A high water table affects the overcome; moderate if soil properties or site amount of usable material. It also affects features are not favorable for the indicated use trafficability. and special planning, design, or maintenance is Drainage is the removal of excess surface needed to overcome or minimize the limitations; and subsurface water from the soil. How easily and severe if soil properties or site features are and effectively the soil is drained depends on the so unfavorable or so difficult to overcome that depth to bedrock, to a cemented pan, or to other special design, significant increase in layers that affect the rate of water movement; construction costs, and possibly increased permeability; depth to a high water table or depth maintenance are required. of standing water if the soil is subject to ponding; This table also gives for each soil the slope; susceptibility to flooding; subsidence of restrictive features that affect drainage, and organic layers; and the potential for frost action. irrigation. Excavating and grading and the stability of Pond reservoir areas hold water behind a dam ditchbanks are affected by depth to bedrock or to or embankment. Soils best suited to this use a cemented pan, large stones, slope, and the have low seepage potential in the upper 60 hazard of cutbanks caving. The productivity of inches. The seepage potential is determined by the soil after drainage is adversely affected by the permeability of the soil and the depth to extreme acidity or by toxic substances in the root fractured bedrock or other permeable material. zone, such as salts, sodium, and sulfur. Excessive slope can affect the storage capacity Availability of drainage outlets is not considered of the reservoir area. in the ratings. Embankments, dikes, and levees are raised Irrigation is the controlled application of structures of soil material, generally less than 20 water to supplement rainfall and support plant feet high, constructed to impound water or to growth. The design and management of an protect land against overflow. In this table, the irrigation system are affected by depth to the soils are rated as a source of material for water table, the need for drainage, flooding, embankment fill. The ratings apply to the soil available water capacity, intake rate, permeability, material below the surface layer to a depth of erosion hazard, and slope. The construction of a about 5 feet. It is assumed that soil layers will be system is affected by large stones and depth to uniformly mixed and compacted during bedrock or to a cemented pan. The performance construction. of a system is affected by the depth of the root The ratings do not indicate the ability of the zone, the amount of salts or sodium, and soil natural soil to support an embankment. Soil reaction.

149

Soil Properties

Data relating to soil properties are collected much as about 15 percent, an appropriate during the course of the soil survey. The data and modifier is added, for example, “gravelly.” Textural the estimates of soil and water features, listed in terms are defined in the Glossary. tables, are explained on the following pages. Classification of the soils is determined Soil properties are determined by field according to the Unified soil classification system examination of the soils and by laboratory index (3, 9) and the system adopted by the American testing of some benchmark soils. Established Association of State Highway and Transportation standard procedures are followed. During the Officials (2, 9). survey, many shallow borings are made and The Unified system classifies soils according examined to identify and classify the soils and to to properties that affect their use as construction delineate them on the soil maps. material. Soils are classified according to grain- Estimates of soil properties are based on field size distribution of the fraction less than 3 inches examinations, on laboratory tests of samples in diameter and according to plasticity index, from the survey area, and on laboratory tests of liquid limit, and organic matter content. Sandy samples of similar soils in nearby areas. Tests and gravelly soils are identified as GW, GP, GM, verify field observations, verify properties that GC, SW, SP, SM, and SC; silty and clayey soils cannot be estimated accurately by field as ML, CL, OL, MH, CH, and OH; and highly observation, and help to characterize key soils. organic soils as PT. Soils exhibiting engineering The estimates of soil properties shown in the properties of two groups can have a dual tables include the range of grain-size distribution classification, for example, CL-ML. and Atterberg limits, the engineering The AASHTO system classifies soils classification, and the physical and chemical according to those properties that affect roadway properties of the major layers of each soil. construction and maintenance. In this system, Pertinent soil and water features also are given. the fraction of a mineral soil that is less than 3 inches in diameter is classified in one of seven Engineering Index Properties groups from A-1 through A-7 on the basis of grain-size distribution, liquid limit, and plasticity Table 12 gives estimates of the engineering index. Soils in group A-1 are coarse grained and classification and of the range of index properties low in content of fines (silt and clay). At the other for the major layers of each soil in the survey extreme, soils in group A-7 are fine grained. area. Most soils have layers of contrasting Highly organic soils are classified in group A-8 on properties within the upper 5 or 6 feet. the basis of visual inspection. Depth to the upper and lower boundaries of Rock fragments larger than 10 inches in each layer is indicated. The range in depth and diameter and 3 to 10 inches in diameter are information on other properties of each layer are indicated as a percentage of the total soil on a given for each soil series under the heading “Soil dry-weight basis. The percentages are estimates Series and Their Morphology.” determined mainly by converting volume Texture is given in the standard terms used by percentage in the field to weight percentage. the U.S. Department of Agriculture. These terms Percentage (of soil particles) passing are defined according to percentages of sand, designated sieves is the percentage of the soil silt, and clay in the fraction of the soil that is less fraction less than 3 inches in diameter based on than 2 millimeters in diameter. “Loam,” for an ovendry weight. The sieves, numbers 4, 10, example, is soil that is 7 to 27 percent clay, 28 to 40, and 200 (USA Standard Series), have 50 percent silt, and less than 52 percent sand. If openings of 4.76, 2.00, 0.420, and 0.074 the content of particles coarser than sand is as millimeters, respectively. Estimates are based on 150 Soil Survey

laboratory tests of soils sampled in the survey bulk density is influenced by texture, kind of clay, area and in nearby areas and on estimates made content of organic matter, and soil structure. in the field. Permeability refers to the ability of a soil to Liquid limit and plasticity index (Atterberg transmit water or air. The estimates indicate the limits) indicate the plasticity characteristics of a rate of downward movement of water when the soil. The estimates are based on test data from soil is saturated. They are based on soil the survey area or from nearby areas and on field characteristics observed in the field, particularly examination. structure, porosity, and texture. Permeability is The estimates of grain-size distribution, liquid considered in the design of soil drainage systems limit, and plasticity index are generally rounded to and septic tank absorption fields. the nearest 5 percent. Thus, if the ranges of Available water capacity refers to the quantity gradation and Atterberg limits extend a marginal of water that the soil is capable of storing for use amount (1 or 2 percentage points) across by plants. The capacity for water storage is given classification boundaries, the classification in the in inches of water per inch of soil for each major marginal zone is omitted in the table. soil layer. The capacity varies, depending on soil properties that affect the retention of water and Physical and Chemical Properties the depth of the root zone. The most important properties are the content of organic matter, soil Table 13 shows estimates of some texture, bulk density, and soil structure. Available characteristics and features that affect soil water capacity is an important factor in the behavior. These estimates are given for the major choice of plants or crops to be grown and in the layers of each soil in the survey area. The design and management of irrigation systems. estimates are based on field observations and on Available water capacity is not an estimate of the test data for these and similar soils. quantity of water actually available to plants at Clay as a soil separate consists of mineral soil any given time. particles that are less than 0.002 millimeter in Soil reaction is a measure of acidity or diameter. In this table, the estimated clay content alkalinity and is expressed as a range in pH of each major soil layer is given as a percentage, values. The range in pH of each major horizon is by weight, of the soil material that is less than 2 based on many field tests. For many soils, millimeters in diameter. values have been verified by laboratory analyses. The amount and kind of clay greatly affect Soil reaction is important in selecting crops and the fertility and physical condition of the soil. other plants, in evaluating soil amendments for They determine the ability of the soil to adsorb fertility and stabilization, and in determining the cations and to retain moisture. They influence risk of corrosion. shrink-swell potential, permeability, plasticity, Salinity is a measure of soluble salts in the the ease of soil dispersion, and other soil soil at saturation. It is expressed as the electrical properties. The amount and kind of clay in a conductivity of the saturation extract, in soil also affect tillage and earthmoving millimhos per centimeter at 25 degrees C. operations. Estimates are based on field and laboratory Moist bulk density is the weight of soil measurements at representative sites of (ovendry) per unit volume. Volume is measured nonirrigated soils. The salinity of irrigated soils is when the soil is at field moisture capacity, that is, affected by the quality of the irrigation water and 1 the moisture content at /3-bar moisture tension. by the frequency of water application. Hence, the Weight is determined after drying the soil at 105 salinity of soils in individual fields can differ degrees C. In this table, the estimated moist bulk greatly from the value given in the table. Salinity density of each major soil horizon is expressed in affects the suitability of a soil for crop production, grams per cubic centimeter of soil material that is the stability of soil if used as construction less than 2 millimeters in diameter. Bulk density material, and the potential of the soil to corrode data are used to compute shrink-swell potential, metal and concrete. available water capacity, total pore space, and Shrink-swell potential is the potential for other soil properties. The moist bulk density of a volume change in a soil with a loss or gain in soil indicates the pore space available for water moisture. Volume change occurs mainly because and roots. A bulk density of more than 1.6 can of the interaction of clay minerals with water and restrict water storage and root penetration. Moist varies with the amount and type of clay minerals Jerome-Twin Falls, Idaho 151

in the soil. The size of the load on the soil and the loams, and silty clay loams that are more than 35 magnitude of the change in soil moisture content percent clay. influence the amount of swelling of soils in place. 5. Noncalcareous loams and silt loams that Laboratory measurements of swelling of are less than 20 percent clay and sandy clay undisturbed clods were made for many soils. For loams, sandy clays, and hemic soil material. others, swelling was estimated on the basis of 6. Noncalcareous loams and silt loams that the kind and amount of clay minerals in the soil are more than 20 percent clay and noncalcareous and on measurements of similar soils. clay loams that are less than 35 percent clay. If the shrink-swell potential is rated moderate 7. Silts, noncalcareous silty clay loams that to very high, shrinking and swelling can cause are less than 35 percent clay, and fibric soil damage to buildings, roads, and other structures. material. Special design is often needed. 8. Soils that are not subject to wind erosion Shrink-swell potential classes are based on because of coarse fragments on the surface or the change in length of an unconfined clod as because of surface wetness. moisture content is increased from air-dry to field Organic matter is the plant and animal residue capacity. The classes are low, a change of less in the soil at various stages of decomposition. In than 3 percent; moderate, 3 to 6 percent; high, the table, the estimated content of organic matter more than 6 percent; and very high, greater than is expressed as a percentage, by weight, of the 9 percent. soil material that is less than 2 millimeters in Erosion factor K indicates the susceptibility of diameter. a soil to sheet and rill erosion by water. Factor K The content of organic matter in a soil can be is one of six factors used in the Universal Soil maintained or increased by returning crop residue Loss Equation (USLE) to predict the average to the soil. Organic matter affects the available annual rate of soil loss by sheet and rill erosion in water capacity, infiltration rate, and tilth. It is a tons per acre per year. The estimates are based source of nitrogen and other nutrients for crops. primarily on percentage of silt, sand, and organic matter (up to 4 percent) and on soil structure and Soil and Water Features permeability. Values of K range from 0.02 to 0.64. Other factors being equal, the higher the value, Table 14 gives estimates of various water the more susceptible the soil is to sheet and rill features. The estimates are used in land use erosion by water. planning that involves engineering considerations. Erosion factor T is an estimate of the Hydrologic soil groups are based on estimates maximum average annual rate of soil erosion by of runoff potential. Soils are assigned to one of wind or water that can occur without affecting four groups according to the rate of water crop productivity over a sustained period. The infiltration when the soils are not protected by rate is in tons per acre per year. vegetation, are thoroughly wet, and receive Wind erodibility groups are made up of soils precipitation from long-duration storms. that have similar properties affecting their The four hydrologic soil groups are: resistance to wind erosion in cultivated areas. Group A. Soils having a high infiltration rate The groups indicate the susceptibility of soil to (low runoff potential) when thoroughly wet. These wind erosion. The soils assigned to group 1 are consist mainly of deep, well drained to the most susceptible to wind erosion, and those excessively drained sands or gravelly sands. assigned to group 8 are the least susceptible. The These soils have a high rate of water groups are as follows: transmission. 1. Coarse sands, sands, fine sands, and Group B. Soils having a moderate infiltration very fine sands. rate when thoroughly wet. These consist chiefly 2. Loamy coarse sands, loamy sands, loamy of moderately deep or deep, moderately well fine sands, loamy very fine sands, ash material, drained or well drained soils that have moderately and sapric soil material. fine texture to moderately coarse texture. These 3. Coarse sandy loams, sandy loams, fine soils have a moderate rate of water transmission. sandy loams, and very fine sandy loams. Group C. Soils having a slow infiltration rate 4L. Calcareous loams, silt loams, clay when thoroughly wet. These consist chiefly of loams, and silty clay loams. soils having a layer that impedes the downward 4. Clays, silty clays, noncalcareous clay movement of water or soils of moderately fine 152 Soil Survey

texture or fine texture. These soils have a slow detailed engineering surveys that delineate flood- rate of water transmission. prone areas at specific flood frequency levels. Group D. Soils having a very slow infiltration High water table (seasonal) is the highest level rate (high runoff potential) when thoroughly wet. of a saturated zone in the soil in most years. The These consist chiefly of clays that have a high estimates are based mainly on observations of shrink-swell potential, soils that have a high water the water table at selected sites and on the table, soils that have a claypan or clay layer at or evidence of a saturated zone, namely grayish near the surface, and soils that are shallow over colors or mottles (redoximorphic features) in the nearly impervious material. These soils have a soil. Indicated in the table are the depth to the very slow rate of water transmission. seasonal high water table; the kind of water table- If a soil is assigned to two hydrologic groups in that is, perched, apparent, or artesian; and the the table, the first letter is for drained areas and months of the year that the water table commonly the second is for undrained areas. is high. A water table that is seasonally high for Flooding, the temporary inundation of an area, less than 1 month is not indicated in the table. is caused by overflowing streams, by runoff from An apparent water table is a thick zone of free adjacent slopes, or by tides. Water standing for water in the soil. It is indicated by the level at short periods after rainfall or snowmelt is not which water stands in an uncased borehole after considered flooding, and water standing in adequate time is allowed for adjustment in the swamps and marshes is considered ponding surrounding soil. A perched water table is water rather than flooding. standing above an unsaturated zone. In places an The table gives the frequency and duration of upper, or perched, water table is separated from a flooding and the time of year when flooding is lower one by a dry zone. An artesian water table most likely. is under hydrostatic head, generally below an Frequency, duration, and probable dates of impermeable layer. When this layer is penetrated, occurrence are estimated. Frequency is the water level rises in an uncased borehole. expressed as none, rare, occasional, and Two numbers in the column showing depth to frequent. None means that flooding is not the water table indicate the normal range in depth probable; rare that it is unlikely but possible under to a saturated zone. Depth is given to the nearest unusual weather conditions (the chance of half foot. The first numeral in the range indicates flooding is nearly 0 percent to 5 percent in any the highest water level. A plus sign preceding the year); occasional that it occurs, on the average, range in depth indicates that the water table is once or less in 2 years (the chance of flooding is above the surface of the soil. “More than 6.0” 5 to 50 percent in any year); and frequent that it indicates that the water table is below a depth of occurs, on the average, more than once in 2 6 feet or that it is within a depth of 6 feet for less years (the chance of flooding is more than 50 than a month. percent in any year). Common is used when the Table 15 gives estimates of various soil occasional and frequent classes are grouped for features. The estimates are used in land use certain purposes. Duration is expressed as very planning that involves engineering considerations. brief if less than 2 days, brief if 2 to 7 days, long Depth to bedrock is given if bedrock is within a if 7 days to 1 month, and very long if more than 1 depth of 5 feet. The depth is based on many soil month. Probable dates are expressed in months. borings and on observations during soil mapping. About two-thirds to three-fourths of all flooding The rock is either soft or hard. If the rock is soft occurs during the stated period. or fractured, excavations can be made with The information is based on evidence in the trenching machines, backhoes, or small rippers. soil profile, namely thin strata of gravel, sand, If the rock is hard or massive, blasting or special silt, or clay deposited by floodwater; irregular equipment generally is needed for excavation. decrease in organic matter content with A cemented pan is a cemented or indurated increasing depth; and little or no horizon subsurface layer within a depth of 5 feet. Such development. a pan causes difficulty in excavation. Pans are Also considered are local information about the classified as thin or thick. A thin pan is less than extent and levels of flooding and the relation of 3 inches thick if continuously indurated or less each soil on the landscape to historic floods. than 18 inches thick if discontinuous or Information on the extent of flooding based on fractured. Excavations can be made by soil data is less specific than that provided by trenching machines, backhoes, or small rippers. Jerome-Twin Falls, Idaho 153

A thick pan is more than 3 inches thick if induced electrochemical or chemical action that continuously indurated or more than 18 inches dissolves or weakens uncoated steel or concrete. thick if discontinuous or fractured. Such a The rate of corrosion of uncoated steel is pan is so thick or massive that blasting or related to such factors as soil moisture, particle- special equipment is needed in excavation. size distribution, acidity, and electrical Potential frost action is the likelihood of conductivity of the soil. The rate of corrosion of upward or lateral expansion of the soil caused concrete is based mainly on the sulfate and by the formation of segregated ice lenses (frost sodium content, texture, moisture content, and heave) and the subsequent collapse of the soil acidity of the soil. Special site examination and and loss of strength on thawing. Frost action design may be needed if the combination of occurs when moisture moves into the freezing factors results in a severe hazard of corrosion. zone of the soil. Temperature, texture, density, The steel in installations that intersect soil permeability, content of organic matter, and depth boundaries or soil layers is more susceptible to to the water table are the most important factors corrosion than steel in installations that are considered in evaluating the potential entirely within one kind of soil or within one soil for frost action. It is assumed that the soil is not layer. insulated by vegetation or snow and is not For uncoated steel, the risk of corrosion, artificially drained. Silty and highly structured, expressed as low, moderate, or high, is based clayey soils that have a high water table in on soil drainage class, total acidity, electrical winter are the most susceptible to frost action. resistivity near field capacity, and electrical Well drained, very gravelly, or very sandy soils conductivity of the saturation extract. are the least susceptible. Frost heave and low For concrete, the risk of corrosion is also soil strength during thawing cause damage expressed as low, moderate, or high. It is based mainly to pavements and other rigid structures. on soil texture, acidity, and amount of sulfates in Risk of corrosion pertains to potential soil- the saturation extract.

155

Classification of the Soils

The system of soil classification used by the adjectives preceding the name of the great National Cooperative Soil Survey has six group. The adjective Xerollic identifies the categories (15). Beginning with the broadest, subgroup that typifies the great group. An these categories are the order, suborder, great example is Xerollic Durargids. group, subgroup, family, and series. FAMILY. Families are established within a Classification is based on soil properties subgroup on the basis of physical and chemical observed in the field or inferred from those properties and other characteristics that affect observations or from laboratory measurements. management. Generally, the properties are Table 16 shows the classification of the soils in those of horizons below plow depth where the survey area. The categories are defined in there is much biological activity. Among the the following paragraphs. properties and characteristics considered are ORDER. Eleven soil orders are recognized. particle size, mineral content, soil temperature The differences among orders reflect the regime, soil depth, and reaction. A family name dominant soil-forming processes and the degree consists of the name of a subgroup preceded of soil formation. Each order is identified by a by terms that indicate soil properties. An word ending in sol. An example is Aridisol. example is fine-loamy, mixed, mesic Xerollic SUBORDER. Each order is divided into Durargids. suborders primarily on the basis of properties SERIES. The series consists of soils within a that influence soil genesis and are important to family that have horizons similar in color, texture, plant growth or properties that reflect the most structure, reaction, consistence, mineral and important variables within the orders. The last chemical composition, and arrangement in the syllable in the name of a suborder indicates the profile. order. An example is Argid (Arg, meaning clay, plus id, from Aridisol). GREAT GROUP. Each suborder is divided into Soil Series and Their great groups on the basis of close similarities in Morphology kind, arrangement, and degree of development of pedogenic horizons; soil moisture and In this section, each soil series recognized in temperature regimes; type of saturation; and the survey area is described. Characteristics of base status. Each great group is identified by the the soil and the material in which it formed are name of a suborder and by a prefix that indicates identified for each series. A pedon, a small three- a property of the soil. An example is Durargids dimensional area of soil, that is typical of the (Dur, meaning presence of a duripan, plus argid, series in the survey area is described. The the suborder of the Aridisols that have an argillic detailed description of each soil horizon follows horizon). standards in the “Soil Survey Manual” (18). Many SUBGROUP. Each great group has a typic of the technical terms used in the descriptions subgroup. Other subgroups are intergrades or are defined in “Soil Taxonomy” (15) and in “Keys extragrades. The typic subgroup is the central to Soil Taxonomy” (17). Unless otherwise concept of the great group; it is not necessarily indicated, colors in the descriptions are for dry the most extensive. Intergrades are transitions to soil. Following the pedon description is the range other orders, suborders, or great groups. of important characteristics of the soils in the Extragrades have some properties that are not series. representative of the great group but do not The map units of each soil series are indicate transitions to any other taxonomic class. described in the section “Detailed Soil Map Each subgroup is identified by one or more Units.” 156 Soil Survey

Ackett Series 2Btk—8 to 14 inches; very pale brown (10YR 7/3) very gravelly clay loam, pale brown (10YR Depth class: Shallow to a duripan 6/3) moist; weak medium subangular blocky Drainage class: Well drained structure; hard, firm, sticky and plastic; few Permeability: Very slow very fine and fine roots; few very fine tubular Position on landscape: Stream terraces pores; common distinct clay films on faces of Parent material: Kind—alluvium; source—welded peds and in pores; 40 percent gravel-sized tuff duripan fragments; violently effervescent (25 Slope range: 2 to 25 percent percent calcium carbonate equivalent); Elevation: 4,900 to 5,600 feet moderately alkaline; abrupt smooth boundary. Average annual precipitation: 10 to 12 inches 2Bkqm—14 to 28 inches; white (10YR 8/1) Average annual air temperature: 46 to 49 fractured indurated duripan, very pale brown degrees F (10YR 7/3) moist; massive; many continuous Frost-free period: 90 to 120 days silica-cemented laminations throughout the 1 duripan; fractures are /4 inch wide and 20 Taxonomic class: Clayey-skeletal, inches apart; few very fine roots in fractures montmorillonitic, mesic, shallow Xerollic of duripan; violently effervescent; abrupt Durargids smooth boundary. Typical Pedon 3Bkq—28 to 50 inches; multicolored extremely gravelly sand; single grain; loose in places; A1—0 to 1 inch; pale brown (10YR 6/3) extremely weakly lime- and silica-cemented with lime gravelly clay loam, brown (10YR 5/3) moist; pendants on underside of gravel; 80 percent weak medium platy structure; soft, friable, gravel; violently effervescent; moderately sticky and plastic; common very fine and fine alkaline; abrupt smooth boundary. roots; many very fine and fine vesicular R—50 inches; dark gray (N 4/0) welded tuff, very pores; 60 percent gravel and 5 percent dark gray (N 3/0) moist; extremely hard; lime cobbles; strongly alkaline; abrupt smooth coatings on upper boundary. boundary. A2—1 inch to 3 inches; light brownish gray (10YR Typical Pedon Location 6/2) clay, grayish brown (10YR 5/2) moist; Map unit in which located: Ackett extremely moderate medium platy structure; slightly gravelly clay loam, 2 to 10 percent slopes hard, friable, sticky and plastic; common very Location in survey area: About 17 miles fine and fine roots; many very fine and fine southwest of Rogerson, Idaho; in the vesicular pores; 5 percent gravel; strongly 1 1 1 SE /4SE /4NW /4 of sec. 26, T. 16 S., R. 14 E. alkaline; abrupt smooth boundary. Bt—3 to 6 inches; pale brown (10YR 6/3) clay, Range in Characteristics brown (10YR 5/3) moist; weak fine prismatic structure parting to moderate medium Profile: subangular blocky; hard, firm, sticky and Depth to bedrock—40 to 60 inches plastic; common very fine and fine roots; Depth to secondary lime—5 to 14 inches common very fine tubular pores; many Depth to duripan—10 to 20 inches distinct clay films on faces of peds and in A1 horizon: pores; 5 percent gravel; moderately alkaline; Value—5 or 6 dry, 4 or 5 moist abrupt wavy boundary. Chroma—2 or 3 Btkq—6 to 8 inches; light gray (10YR 7/2) Gravel content—30 to 60 percent extremely cobbly clay, very pale brown Cobble content—5 to 15 percent (10YR 7/3) moist; massive; extremely hard, Reaction—mildly alkaline to strongly alkaline extremely firm; common distinct clay films on faces of peds and in pores, many continuous Bt horizon: silica laminations throughout fragments; Value—5 or 6 dry, 4 or 5 moist 1 fractures are /4 inch wide and 8 inches apart; Chroma—3 or 4 few very fine roots in fractures; violently Texture—clay loam or clay effervescent; 70 percent cobbles and 10 Gravel content—5 to 15 percent percent gravel; moderately alkaline; abrupt Clay content—35 to 50 percent smooth boundary. Reaction—mildly alkaline to strongly alkaline Jerome-Twin Falls, Idaho 157

2Btk horizon: many very fine to medium roots; common Value—6 or 7 dry, 4 to 6 moist fine tubular pores; neutral; abrupt smooth Chroma—3 or 4 boundary. Texture—very cobbly clay, extremely cobbly clay, Cg—18 to 60 inches; pale brown (10YR 6/3) very cobbly clay loam, extremely cobbly clay loamy sand, very dark grayish brown (10YR loam, extremely gravelly clay, extremely 3/2) moist; common medium distinct mottles, gravelly clay loam, or very gravelly clay dark yellowish brown (10YR 3/6) moist; single loam grain; loose; common very fine and fine roots; Rock fragment content—40 to 80 percent few fine irregular pores; neutral. Clay content—35 to 55 percent Example Pedon Location Calcium carbonate equivalent—20 to 30 percent Map unit in which located: Aeric Fluvaquents 2Bkqm horizon: Location in survey area: About 14 miles south of Value—7 or 8 dry 1 1 1 Rogerson, Idaho; in the NE /4SW /4SE /4 of Chroma—1 to 3 sec. 7, T. 15 E., R.15 E. Thickness of duripan—dominantly 8 to 15 inches Range in Characteristics Aeric Fluvaquents Profile: Depth class: Very deep Depth to bedrock—more than 60 inches Drainage class: Somewhat poorly drained to very Depth to water table—6 to 36 inches poorly drained Particle-size control section: Permeability: Slow or moderate Clay content—5 to 45 percent Position on landscape: Flood plains Parent material: Kind—alluvium; source—mixed Ag horizon: Slope range: 0 to 2 percent Value—4 to 6 dry, 2 or 3 moist Elevation: 5,000 to 5,500 feet Chroma—1 or 2 Average annual precipitation: 8 to 12 inches Texture—silty clay, silty clay loam, or silt loam Average annual air temperature: 47 to 49 Cg horizon: degrees F Value—5 or 6 dry, 2 or 3 moist Frost-free period: 100 to 110 days Chroma—1 to 3 Taxonomic class: Aeric Fluvaquents Texture—stratified loamy sand to silty clay loam

Example Pedon Amboat Series Ag1—0 to 4 inches; light brownish gray (10YR Depth class: Very deep 6/3) silty clay loam, very dark grayish brown Drainage class: Well drained (10YR 3/2) moist; common medium distinct Permeability: Very slow mottles, yellow (10YR 7/6) dry; moderate Position on landscape: Summits coarse platy structure; hard, firm, sticky and Parent material: Kind—colluvium and residuum; plastic; many very fine to medium roots; source—welded tuff common fine tubular pores; neutral; clear Slope range: 2 to 20 percent smooth boundary. Elevation: 5,800 to 6,600 feet Ag2—4 to 13 inches; light brownish gray (10YR Average annual precipitation: 13 to 16 inches 6/2) silty clay loam, very dark grayish brown Average annual air temperature: 40 to 44 (10YR 3/2) moist; common coarse distinct degrees F mottles, yellow (10YR 7/6) dry; moderate Frost-free period: 70 to 90 days medium platy structure; hard, firm, sticky and plastic; many very fine to medium roots; Taxonomic class: Clayey-skeletal, common fine tubular pores; neutral; clear montmorillonitic, frigid Typic Palexerolls smooth boundary. Typical Pedon Ag3—13 to 18 inches; dark gray (10YR 4/1 silty clay, black (10YR 2/1) moist; common fine A—0 to 3 inches; dark brown (10YR 4/3) gravelly distinct mottles, dark yellowish brown (10YR loam, very dark grayish brown (10YR 3/2) 3/6) moist; moderate medium platy structure; moist; weak fine granular structure; slightly 158 Soil Survey

hard, friable, slightly sticky and slightly Bt1 horizon: plastic; many very fine, fine, and coarse Value—4 or 5 dry, 2 or 3 moist roots; many very fine tubular pores; 20 Chroma—2 or 3 percent gravel; neutral; clear smooth Texture—gravelly clay loam, gravelly silty clay boundary. loam, or gravelly clay AB—3 to 8 inches; dark brown (10YR 4/3) Gravel content—15 to 30 percent gravelly loam, very dark brown (10YR 2/2) Cobble content—0 to 5 percent moist; weak medium subangular blocky Clay content—35 to 55 percent structure; slightly hard, friable, sticky and 2Bt2 horizon: plastic; many very fine, fine, and coarse Hue—7.5YR or 10YR roots; many very fine tubular pores; 15 Value—4 or 5 dry, 3 to 5 moist percent gravel; neutral; clear smooth Chroma—2 to 4 boundary. Cobble content—0 to 5 percent Bt1—8 to 17 inches; dark brown (10YR 4/3) Stone content—60 to 85 percent gravelly clay, dark brown (10YR 3/3) moist; Clay content—60 to 85 percent moderate medium subangular blocky structure; hard, firm, sticky and plastic; common roots; common very fine tubular Aninto Series pores; common distinct clay films on faces of Depth class: Very deep peds and in pores; 30 percent gravel; neutral; Drainage class: Well drained abrupt smooth boundary. Permeability: Ver y slow 2Bt2—17 to 60 inches; brown (7.5YR 4/2) Position on landscape: Terraces extremely stony clay, dark brown (7.5YR 4/4) Parent material: Kind—alluvium; source—welded moist; strong medium angular blocky tuff structure; very hard, very firm, very sticky Slope range: 1 to 30 percent and very plastic; common roots; few very fine Elevation: 5,500 to 6,000 feet tubular pores; many prominent clay films on Average annual precipitation: 12 to 16 inches faces of peds and in pores; 85 percent gray Average annual air temperature: 42 to 44 (10YR 5/1) fractured vesicular welded tuff, degrees F very dark gray (10YR 3/1) moist; fractures 1 Frost-free period: 90 to 100 days are /2 inch to 2 inches wide and run perpendicular to the surface; seams of clay in Taxonomic class: Clayey-skeletal, fractures; neutral. montmorillonitic, frigid Typic Palexerolls Typical Pedon Location Typical Pedon Map unit in which located: Brose-Amboat A—0 to 6 inches; brown (10YR 5/3) very gravelly complex, 2 to 20 percent slopes silty clay loam, very dark grayish brown Location in survey area: About 8 miles south of (10YR 3/2) moist; weak fine granular 1 1 1 Rogerson, Idaho; in the NE /4NW /4NW /4 of structure; soft, very friable, slightly sticky sec. 29, T. 15 S., R. 16 E. and slightly plastic; many very fine, fine, and medium roots; many very fine and fine Range in Characteristics tubular pores; 40 percent gravel; slightly acid; abrupt smooth boundary. Profile: Bt1—6 to 13 inches; brown (10YR 4/3) very Depth to bedrock—more than 60 inches gravelly clay, dark brown (10YR 3/3) moist; Thickness of mollic epipedon—12 to 20 inches moderate fine angular blocky structure; very A horizon: hard, very firm, very sticky and very plastic; Value—4 or 5 dry, 2 or 3 moist common very fine, fine, and medium roots; Chroma—1 to 3 common very fine and fine tubular pores; Gravel content—10 to 20 percent many distinct clay films on faces of peds and Cobble content—0 to 10 percent in pores; 40 percent gravel; slightly acid; clear Stone content—0 to 5 percent smooth boundary. Reaction—slightly acid or neutral Bt2—13 to 26 inches; brown (10YR 4/3) very Jerome-Twin Falls, Idaho 159

gravelly silty clay, brown (7.5YR 4/4) moist; A horizon: moderate medium prismatic structure parting Value—4 or 5 dry, 2 or 3 moist to moderate medium angular blocky; very Chroma—2 or 3 hard, very firm, very sticky and very plastic; Bt horizon: common very fine and fine roots; few very Hue—7.5YR or 10YR fine and fine tubular pores; many prominent Value—4 to 6 dry, 3 or 4 moist clay films on faces of peds and in pores; 40 Chroma—3 or 4 percent gravel; slightly acid; gradual wavy Texture—very gravelly clay, very gravelly silty boundary. clay, extremely gravelly silty clay, or Bt3—26 to 41 inches; yellowish brown (10YR 5/4) extremely gravelly clay extremely gravelly silty clay, brown (7.5YR Gravel content—40 to 75 percent 4/4) moist; moderate medium angular blocky structure; very hard, very firm, very sticky and very plastic; common very fine and fine Antelope Springs Series roots; few very fine and fine tubular pores; Depth class: Very deep common distinct clay films on faces of peds Drainage class: Well drained and in pores; 70 percent gravel; neutral; clear Permeability: Slow smooth boundary. Position on landscape: Alluvial fans and 2Btk—41 to 56 inches; dark yellowish brown terraces (10YR 4/4) clay, brown (10YR 4/3) moist; Parent material: Kind—alluvium; source—mixed moderate medium angular blocky structure; Slope range: 0 to 4 percent very hard, very firm, very sticky and very Elevation: 3,000 to 4,500 feet plastic; common very fine and fine roots; few Average annual precipitation: 8 to 10 inches very fine and fine tubular pores; common Average annual air temperature: 49 to 51 distinct clay films on faces of peds and in degrees F pores; slightly effervescent (10 percent Frost-free period: 110 to 140 days calcium carbonate equivalent); few fine irregularly shaped filaments or threads of Taxonomic class: Fine-loamy, mixed, mesic carbonates; neutral; abrupt smooth boundary. Xerollic Natrargids 2Bk—56 to 70 inches; brown (7.5YR 5/4) clay Typical Pedon loam, brown (7.5YR 4/4) moist; massive; hard, firm, very sticky and very plastic; few A—0 to 4 inches; pale brown (10YR 6/3) loam, very fine and fine roots; few very fine and fine brown (10YR 5/3) moist; moderate medium tubular pores; slightly effervescent (11 platy structure; slightly hard, friable, slightly percent calcium carbonate equivalent); few sticky and slightly plastic; common very fine fine irregularly shaped soft masses of roots; common fine vesicular pores; strongly carbonates; mildly alkaline. effervescent; moderately alkaline; clear smooth boundary. Typical Pedon Location Btkn—4 to 13 inches; brown (10YR 5/3) clay loam, dark brown (10YR 4/3) moist; weak Map unit in which located: Aninto complex, 10 to medium subangular blocky structure; hard, 30 percent slopes firm, sticky and plastic; common very fine Location in survey area: About 17 miles roots; common very fine tubular pores; southeast of Rogerson, Idaho; in the 1 1 1 common distinct clay films on faces of peds NW /4SE /4SE /4 of sec. 25, T. 16 S., and in pores; strongly effervescent; strongly R. 17 E. alkaline; clear smooth boundary. Range in Characteristics C1—13 to 25 inches; pale brown (10YR 6/3) loam, dark brown (10YR 4/3) moist; massive; Profile: hard, firm, sticky and plastic; few very fine Depth to bedrock—more than 60 inches roots; few very fine tubular pores; strongly Thickness of mollic epipedon—10 to 15 inches effervescent; lime segregated in filaments; Particle-size control section: very strongly alkaline; gradual wavy Clay content—50 to 59 percent boundary. 160 Soil Survey

C2—25 to 60 inches; pale brown (10YR 6/3) Typical Pedon loam, dark brown (10YR 4/3) moist; massive; A—0 to 4 inches; brown (10YR 5/3) sandy loam, slightly hard, friable, slightly sticky and very dark grayish brown (10YR 3/2) moist; slightly plastic; few very fine roots; few very weak fine granular structure; soft, friable; fine tubular pores; strongly effervescent; lime many roots; many very fine irregular pores; segregated in filaments; very strongly neutral; abrupt smooth boundary. alkaline. Bt1—4 to 8 inches; yellowish brown (10YR 5/4) Typical Pedon Location sandy clay loam, dark brown (10YR 4/3) moist; weak medium subangular blocky Map unit in which located: Antelope Springs structure; slightly hard, friable, slightly sticky loam, 0 to 4 percent slopes and slightly plastic; many very fine and fine Location in survey area: About 4 miles southeast 1 1 1 roots; many very fine and fine tubular pores; of Hollister, Idaho; in the NE /4NE /4NE /4 of few faint clay films on faces of peds and in sec. 12, T. 13 S., R. 16 E. pores; mildly alkaline; gradual wavy boundary. Bt2—8 to 15 inches; light yellowish brown (10YR Range in Characteristics 6/4) sandy clay loam, dark brown (10YR 4/3) Profile: moist; moderate medium subangular blocky Depth to bedrock—more than 60 inches structure; hard, friable, slightly sticky and slightly plastic; common very fine and fine A horizon: roots; many very fine and fine tubular pores; Value—6 or 7 dry, 3 to 5 moist few faint clay films on faces of peds and Chroma—2 or 3 in pores; mildly alkaline; clear smooth Reaction—moderately alkaline or strongly boundary. alkaline Bk—15 to 26 inches; very pale brown (10YR 7/3) Btkn horizon: sandy loam, brown (10YR 5/3) moist; weak Value—5 or 6 dry, 4 or 5 moist medium subangular blocky structure; very Chroma—2 or 3 hard, firm; few very fine and fine roots; few 1 Texture—loam or clay loam fine tubular pores; 5 percent durinodes /2 to 1 Clay content—24 to 34 percent inch in diameter; strongly effervescent (13 Reaction—moderately alkaline or strongly percent calcium carbonate equivalent); few alkaline fine lime filaments; moderately alkaline; clear smooth boundary. C horizon: Bkqm—26 to 40 inches; very pale brown (10YR Value—6 or 7 dry, 4 to 6 moist 7/3) duripan, brown (10YR 5/3) moist; Chroma—3 or 4 1 1 massive; extremely hard; thin ( /16 to /8 inch Clay content—20 to 25 percent thick) continuous laminar cap; subsequent continuous silica-cemented laminations every Arbidge Series 3 to 8 inches; strongly effervescent cemented sandy loam matrix between Depth class: Moderately deep to a duripan laminations; few very fine roots to fractures; Drainage class: Well drained clear wavy boundary. Permeability: Moderately slow 3C—40 to 65 inches; multicolored extremely Position on landscape: Terraces gravelly sand; few very fine roots; lime and Parent material: Kind—alluvium; source—welded silica coatings on underside of gravel; 80 tuff and volcanic ash percent gravel. Slope range: 1 to 4 percent Elevation: 4,400 to 5,500 feet Typical Pedon Location Average annual precipitation: 9 to 12 inches Map unit in which located: Arbidge sandy loam, Average annual air temperature: 45 to 48 1 to 4 percent slopes degrees F Location in survey area: About 5 miles Frost-free period: 100 to 120 days southwest of Rogerson, Idaho; in the 1 1 1 Taxonomic class: Fine-loamy, mixed, mesic NW /4NW /4SW /4 of sec. 26, T. 14 S., Xerollic Durargids R. 15 E. Jerome-Twin Falls, Idaho 161

Range in Characteristics Typical Pedon Profile: A—0 to 2 inches; grayish brown (10YR 5/2) Depth to bedrock—more than 60 inches sandy loam, very dark grayish brown (10YR Depth to secondary lime—10 to 25 inches 3/2) moist; weak medium platy structure; Depth to duripan—20 to 40 inches slightly hard, very friable, slightly sticky and Depth to extremely gravelly sand—22 to 40 slightly plastic; many roots; many very fine inches or more irregular pores; neutral; clear smooth boundary. A horizon: AB—2 to 6 inches; brown (10YR 5/3) loam, very Value—5 or 6 dry, 3 or 4 moist dark grayish brown (10YR 3/2) moist; Chroma—2 or 3 moderate fine subangular blocky structure; Gravel content—0 to 15 percent slightly hard, friable, slightly sticky and Bt horizon: slightly plastic; many roots; many very fine Value—5 or 6 dry, 3 or 4 moist irregular pores; neutral; gradual wavy Chroma—2 to 4 boundary. Texture—sandy clay loam, clay loam, or Bt1—6 to 12 inches; brown (10YR 5/3) sandy loam clay loam, dark brown (10YR 3/3) moist; Gravel content—0 to 10 percent moderate medium subangular blocky Clay content—20 to 30 percent structure; slightly hard, friable, sticky and plastic; common roots; many very fine Bk horizon: irregular pores; few faint clay films on faces Value—6 to 8 dry, 4 to 6 moist of peds and in pores; neutral; clear smooth Chroma—2 to 4 boundary. Texture—sandy loam, sandy clay loam, or Bt2—12 to 19 inches; pale brown (10YR 6/3) gravelly sandy loam sandy clay loam, brown (10YR 4/3) moist; Gravel content—0 to 20 percent strong medium angular blocky structure; Effervescence—strong or violent very hard, firm, sticky and plastic; Reaction—mildly alkaline or moderately common very fine to medium roots; alkaline common very fine irregular pores; common Bkqm horizon: distinct clay films on faces of peds and in 1 Thickness of upper silica lamination— /16 to pores; mildly alkaline; abrupt smooth 1 /8 inch boundary. 1 Thickness of lower silica laminations— /16 to 1 Bkqm—19 to 32 inches; white (10YR 8/1) inch fractured duripan, very pale brown Laminar cap—continuous or intermittent (10YR 7/3) moist; platy; indurated; extremely 1 hard, extremely firm; many /16- to 1 /4-inch-thick lime-and silica-cemented Arness Series lenses mixed with ignimbrite sand and gravel; few very fine and fine roots in fractures of Depth class: Shallow to a duripan 1 duripan; fractures are /4 inch wide and Drainage class: Well drained 8 inches apart; strongly effervescent; Permeability: Moderately slow moderately alkaline; abrupt wavy Position on landscape: Terraces boundary. Parent material: Kind—alluvium; source— R—32 inches; black (10YR 2/1) ignimbrite, black ignimbrite, welded tuff, and volcanic ash (7.5YR 2/0) moist. Slope range: 2 to 6 percent Elevation: 5,100 to 5,900 feet Typical Pedon Location Average annual precipitation: 11 to 13 inches Average annual air temperature: 43 to 46 Map unit in which located: Arness sandy loam, 2 degrees F to 6 percent slopes Frost-free period: 90 to 100 days Location in survey area: About 16 miles west of 1 1 1 Taxonomic class: Loamy, mixed, frigid, shallow Rogerson, Idaho; in the NW /4NE /4SE /4 of Aridic Durixerolls sec. 23, T. 14 S., R. 13 E. 162 Soil Survey

Range in Characteristics equivalent); mildly alkaline; clear smooth boundary. Profile: BA—3 to 9 inches; pale brown (10YR 6/3) silt Depth to bedrock—20 to 40 inches loam, grayish brown (10YR 5/2) moist; weak Depth to duripan—14 to 20 inches medium subangular block structure; slightly Thickness of mollic epipedon—7 to 12 inches hard, friable; many very fine and fine roots; Particle-size control section: many very fine and fine tubular pores; Clay content—22 to 34 percent strongly effervescent (8 percent calcium carbonate equivalent); moderately alkaline; A horizon: gradual wavy boundary. Value—4 or 5 dry, 2 or 3 moist Bk1—9 to 22 inches; very pale brown (10YR 7/3) Chroma—2 or 3 silt loam, brown (10YR 5/3) moist; weak Gravel content—0 to 10 percent medium subangular blocky structure; hard, Bt horizon: firm; few very fine and fine roots; many very Value—5 or 6 dry, 3 or 4 moist fine and fine tubular pores; strongly Chroma—2 to 4 effervescent (18 percent calcium carbonate Texture—sandy clay loam or gravelly sandy clay equivalent); moderately alkaline; gradual loam wavy boundary. Gravel content—0 to 20 percent Bk2—22 to 40 inches; pale brown (10YR 6/3) silt Reaction—neutral or mildly alkaline loam, brown (10YR 5/3) moist; massive; slightly hard, friable; few very fine and fine Bkqm horizon: 1 1 roots; common fine tubular pores; strongly Thickness of upper silica lamination— /16 to /2 effervescent (15 percent calcium carbonate inch equivalent); moderately alkaline; gradual Thickness of lower silica laminations—2 inches wavy boundary. or less Bk3—40 to 53 inches; pale brown (10YR 6/3) silt Cementation between laminations—weak to loam, brown (10YR 5/3) moist; massive; very strong hard, friable; few very fine roots; common fine Thickness of duripan—3 to 15 inches tubular pores; strongly effervescent (10 percent calcium carbonate equivalent); Bahem Series moderately alkaline; gradual wavy boundary. Bk4—53 to 70 inches; pale brown (10YR 6/3) silt Depth class: Very deep loam, brown (10YR 5/3) moist; massive; Drainage class: Well drained slightly hard, friable; common fine tubular Permeability: Moderate pores; strongly effervescent (10 percent Position on landscape: Terraces calcium carbonate equivalent); moderately Parent material: Kind—loess and alluvium; alkaline. source—mixed Slope range: 1 to 12 percent Typical Pedon Location Elevation: 3,500 to 4,500 feet Map unit in which located: Bahem silt loam, 4 to Average annual precipitation: 8 to 10 inches 8 percent slopes Average annual air temperature: 48 to 50 Location in survey area: About 21 miles degrees F northwest of Buhl, Idaho; in the Frost-free period: 120 to 140 days 1 1 1 SW /4NE /4SE /4 of sec. 29, T. 6 S., R. 13 E. Taxonomic class: Coarse-silty, mixed, mesic Xerollic Calciorthids Range in Characteristics Profile: Typical Pedon Depth to bedrock—more than 60 inches A—0 to 3 inches; pale brown (10YR 6/3) silt Depth to secondary lime—8 to 10 inches loam, dark grayish brown (10YR 4/2) moist; Particle-size control section: moderate medium platy structure; soft, Clay content—10 to 18 percent friable; many very fine and fine roots; many very fine and fine tubular pores; strongly A horizon: effervescent (9 percent calcium carbonate Chroma—2 or 3 Jerome-Twin Falls, Idaho 163

Reaction—mildly alkaline or moderately alkaline hard, friable, slightly sticky and slightly plastic; common fine and very fine roots; few Bk horizon: fine tubular pores; few faint clay films in Value—6 or 7 dry, 4 or 5 moist pores; mildly alkaline; abrupt smooth Chroma—2 or 3 boundary. Texture—silt loam or very fine sandy loam Bt2—14 to 17 inches; brown (10YR 5/3) loam, Calcium carbonate equivalent—10 to 30 percent dark yellowish brown (10YR 3/4) moist; weak Durinode content—0 to 10 percent medium to coarse subangular blocky structure; slightly hard, friable, slightly sticky Banbury Series and slightly plastic; few fine and very fine roots; few fine tubular pores; few faint clay Depth class: Shallow to basalt films in pores; mildly alkaline; abrupt wavy Drainage class: Well drained boundary. Permeability: Moderate R1—17 to 19 inches; fractured basalt; coatings of Position on landscape: Terraces lime on underside of fragments. Parent material: Kind—alluvium and residuum; R2—19 inches; basalt. source—basalt Slope range: 2 to 20 percent Typical Pedon Location Elevation: 3,000 to 4,500 feet Map unit in which located: Banbury loam, 2 to 12 Average annual precipitation: 8 to 10 percent slopes inches Location in survey area: About 2 miles north of Average annual air temperature: 49 to 51 1 1 1 Buhl, Idaho; in the SW /4SW /4NW /4 of sec. degrees F 24, T. 9 S., R. 14 E. Frost-free period: 120 to 140 days Taxonomic class: Loamy, mixed, mesic Lithic Range in Characteristics Xerollic Haplargids Profile: Depth to bedrock—10 to 20 inches Typical Pedon Reaction—mildly alkaline or moderately A1—0 to 3 inches; dark grayish brown (10YR 4/2) alkaline loam, dark brown (10YR 3/3) moist; weak A1 horizon: thick platy structure parting to weak medium Value—4 to 6 dry, 2 to 4 moist to fine granular; soft, very friable; many fine Chroma—2 or 3 and very fine roots; common very fine irregular pores; mildly alkaline; abrupt smooth Bt horizon: boundary. Value—4 to 6 dry, 3 or 4 moist A2—3 to 5 inches; brown (10YR 4/3) loam, dark Chroma—2 to 4 brown (10YR 3/3) moist; weak medium to fine Texture—loam, clay loam, or gravelly loam granular structure; soft, very friable, slightly Gravel content—0 to 20 percent sticky; common fine and very fine roots; few Clay content—25 to 33 percent very fine tubular pores and common very fine irregular pores; mildly alkaline; abrupt smooth Bancy Series boundary. BA—5 to 10 inches; brown (10YR 4/3) loam, Depth class: Shallow to a duripan dark brown (10YR 3/3) moist; weak medium Drainage class: Well drained prismatic structure parting to weak medium Permeability: Slow subangular blocky; soft, very friable, slightly Position on landscape: Terraces sticky and slightly plastic; common very Parent material: Kind—alluvium; source—welded fine and fine roots; few very fine tubular tuff and volcanic ash pores; mildly alkaline; abrupt smooth Slope range: 2 to 12 percent boundary. Elevation: 5,500 to 6,000 feet Bt1—10 to 14 inches; brown (10YR 5/3) loam, Average annual precipitation: 12 to 16 inches dark yellowish brown (10YR 3/4) moist; weak Average annual air temperature: 42 to 44 medium prismatic structure parting to weak degrees F medium to coarse subangular blocky; slightly Frost-free period: 90 to 100 days 164 Soil Survey

Taxonomic class: Clayey, montmorillonitic, frigid, Gravel content—15 to 25 percent shallow Typic Durixerolls Cobble content—0 to 5 percent Bt horizon: Typical Pedon Value—4 to 6 A—0 to 3 inches; brown (10YR 5/3) gravelly clay Chroma—3 or 4 loam, dark brown (10YR 3/3) moist; weak Gravel content—0 to 10 percent medium granular structure; soft, very friable, Cobble content—0 to 5 percent slightly sticky and slightly plastic; many very Btkq horizon (where present): fine to fine roots; many fine vesicular pores; Rock fragment content—5 to 35 percent 25 percent gravel; neutral; abrupt smooth boundary. Bkqm horizon: Bt1—3 to 8 inches; brown (10YR 5/3) clay, dark Thickness of upper silica lamination—3 to 6 brown (10YR 3/3) moist; moderate medium inches subangular blocky structure; hard, firm, very Thickness of lower silica laminations—2 to 4 sticky and very plastic; common very fine inches roots; common very fine tubular pores; many Thickness of duripan—10 to 20 inches distinct clay films on faces of peds and in pores; neutral; abrupt wavy boundary. Barrymore Series Bt2—8 to 17 inches; yellowish brown (10YR 5/4) clay, dark yellowish brown (10YR 3/4) moist; Depth class: Moderately deep to basalt moderate medium angular blocky structure; Drainage class: Well drained very hard, firm, very sticky and very plastic; Permeability: Moderate few very fine roots; common very fine tubular Position on landscape: Terraces pores; many distinct clay films on faces of Parent material: Kind—alluvium and loess; peds and in pores; neutral; abrupt wavy source—mixed boundary. Slope range: 1 to 4 percent Bkqm—17 to 31 inches; white (10YR 8/1) Elevation: 3,500 to 4,000 feet duripan, very pale brown (10YR 7/3) moist; Average annual precipitation: 9 to 11 inches massive; extremely hard, extremely firm; Average annual air temperature: 47 to 49 many continuous silica-cemented degrees F laminations throughout duripan; violently Frost-free period: 130 to 140 days effervescent; abrupt wavy boundary. Taxonomic class: Coarse-silty, mixed, mesic 2R—31 inches; fractured welded tuff. Xerollic Camborthids Typical Pedon Location Typical Pedon Map unit in which located: Bancy-Tanner A—0 to 5 inches; yellowish brown (10YR 5/4) complex, 2 to 12 percent slopes silt loam, dark yellowish brown (10YR 4/4) Location in survey area: About 15 miles moist; moderate medium platy structure; soft, southeast of Rogerson, Idaho; in the 1 1 1 friable; common very fine and fine roots; NW /4SE /4SE /4 of sec. 21, T. 16 S., many very fine and fine irregular pores; R. 17 E. neutral; clear smooth boundary. Bw—5 to 17 inches; yellowish brown (10YR 5/4) Range in Characteristics silt loam, brown (10YR 4/3) moist; moderate Profile: medium subangular blocky structure; Depth to bedrock—22 to 40 inches slightly hard, friable; few fine and very fine Depth to duripan—14 to 20 inches roots; common very fine and few fine Thickness of mollic epipedon—7 to 12 inches tubular pores; neutral; clear smooth boundary. Particle-size control section: Bk—17 to 25 inches; very pale brown (10YR 7/3) Clay content—40 to 50 percent silt loam, brown (10YR 5/3) moist; massive; A horizon: hard, friable; few very fine roots; common Value—4 or 5 dry very fine tubular pores; 5 percent gravel; Chroma—2 or 3 strongly effervescent (25 percent calcium Jerome-Twin Falls, Idaho 165

carbonate equivalent); moderately alkaline; and fine roots; many very fine and fine abrupt smooth boundary. tubular pores; 10 percent gravel; neutral; clear 2R—25 inches; fractured basalt; lime coatings on smooth boundary. surface and in fractures. Bt1—5 to 13 inches; pale brown (10YR 6/3) sandy clay loam, brown (10YR 4/3) moist; Typical Pedon Location moderate medium subangular blocky structure; hard, friable, sticky and plastic; Map unit in which located: Barrymore-Starbuck common very fine and fine roots; many very complex, 1 to 4 percent slopes fine and fine tubular pores; few faint clay Location in survey area: About 7 miles north of 1 1 1 films on faces of peds and in pores; 5 Jerome, Idaho; in the NE /4NE /4NW /4 of sec. percent gravel; neutral; gradual wavy 6, T. 7 S., R. 17 E. boundary. Range in Characteristics Bt2—13 to 24 inches; pale brown (10YR 6/3) gravelly sandy clay loam, brown (10YR 4/3) Profile: moist; moderate medium subangular blocky Depth to bedrock—20 to 40 inches structure; hard, friable, sticky and plastic; few Depth to secondary lime—15 to 20 inches very fine and fine roots; common very fine A horizon: and fine tubular pores; common distinct clay Value—5 or 6 dry, 3 or 4 moist films on faces of peds and in pores; 15 Chroma—2 to 4 percent gravel; neutral; gradual wavy boundary. Bw horizon: 2Bw—24 to 30 inches; very pale brown (10YR Value—5 or 6 dry 7/3) gravelly sandy loam, brown (10YR 5/3) Chroma—3 or 4 moist; weak medium subangular blocky Clay content—14 to 20 percent structure; slightly hard, friable; few fine and Bk horizon: very fine roots; few fine and very fine tubular Value—6 or 7 dry, 4 to 6 moist pores; 20 percent gravel; mildly alkaline; Chroma—2 or 3 gradual wavy boundary. Clay content—8 to 18 percent 2Bk—30 to 60 inches; multicolored extremely Gravel content—0 to 10 percent gravelly sand; single grain; loose; weak lime Calcium carbonate equivalent—15 to 30 percent and silica cementation with carbonates and silica coatings on underside of gravel; Blacknest Series strongly effervescent; moderately alkaline. Typical Pedon Location Depth class: Very deep Drainage class: Well drained Map unit in which located: Rakane-Blacknest Permeability: Moderately slow over very rapid complex, 1 to 4 percent slopes Position on landscape: Terraces Location in survey area: About 14 miles Parent material: Kind—old alluvium; source— northwest of Buhl, Idaho; in the 1 1 1 mixed NW /4NW /4SE /4 of sec. 18, T. 8 S., R. 13 E. Slope range: 1 to 15 percent Elevation: 3,000 to 4,000 feet Range in Characteristics Average annual precipitation: 8 to 10 inches Profile: Average annual air temperature: 47 to 49 Depth to bedrock—more than 60 inches degrees F Depth to secondary lime—20 to 40 inches Frost-free period: 120 to 140 days Depth to extremely gravelly sand—20 to 40 Taxonomic class: Fine-loamy, mixed, mesic inches Xerollic Haplargids Particle-size control section: Typical Pedon Rock fragment content—5 to 30 percent Clay content—18 to 30 percent A—0 to 5 inches; pale brown (10YR 6/3) loam, brown (10YR 4/3) moist; moderate medium A horizon: platy structure; slightly hard, friable, slightly Value—3 or 4 moist sticky and slightly plastic; common very fine Chroma—2 or 3 166 Soil Survey

Gravel content—0 to 10 percent very fine and fine irregular pores; 45 percent gravel and 25 percent cobbles; strongly Bt horizon: effervescent; carbonates and silica coatings Chroma—3 or 4 on underside of coarse fragments; mildly Texture—loam, sandy clay loam, clay loam, alkaline; abrupt wavy boundary. gravelly loam, gravelly sandy clay loam, or R—44 inches; welded tuff. gravelly clay loam Typical Pedon Location Bluegulch Series Map unit in which located: Bluegulch gravelly loam, 2 to 12 percent slopes Depth class: Deep to welded tuff Location in survey area: About 12 miles Drainage class: Well drained southwest of Buhl, Idaho; in the Permeability: Moderate 1 1 1 SW /4NW /4NW /4 of sec. 12, T. 10 S., Position on landscape: Ridges and dip slopes R. 12 E. Parent material: Kind—colluvium; source—welded tuff Range in Characteristics Slope range: 2 to 30 percent Profile: Elevation: 3,500 to 4,000 feet Depth to bedrock—40 to 60 inches Average annual precipitation: 8 to 10 inches Depth to secondary lime—18 to 35 inches Average annual air temperature: 49 to 51 Rock fragment content—50 to 70 percent degrees F Frost-free period: 120 to 140 days A horizon: Value—5 or 6 dry, 3 or 4 moist Taxonomic class: Loamy-skeletal, mixed, mesic Gravel content—15 to 30 percent Xerollic Camborthids Bw horizon: Typical Pedon Value—3 or 4 moist A—0 to 4 inches; brown (10YR 5/3) gravelly Gravel content—15 to 45 percent loam, dark brown (10YR 3/3) moist; weak Cobble content—0 to 5 percent medium granular structure; soft, friable, Clay content—18 to 26 percent slightly sticky and slightly plastic; common Bk horizon: very fine, fine, and medium roots; many very Value—4 or 5 moist fine and fine tubular pores; 25 percent gravel; Chroma—2 or 3 neutral; clear smooth boundary. Texture—extremely gravelly sandy loam or Bw1—4 to 12 inches; pale brown (10YR 6/3) extremely gravelly loam gravelly loam, brown (10YR 4/3) moist; weak Gravel content—45 to 55 percent medium subangular blocky structure; slightly Cobble content—10 to 25 percent hard, friable, slightly sticky and slightly plastic; common very fine, fine, and medium roots; many very fine and fine tubular pores; Brose Series 15 percent gravel; neutral; gradual wavy Depth class: Shallow to welded tuff boundary. Drainage class: Well drained Bw2—12 to 20 inches; pale brown (10YR 6/3) Permeability: Ver y slow very gravelly loam, brown (10YR 4/3) moist; Position on landscape: Summits moderate medium subangular blocky Parent material: Kind—colluvium and residuum; structure; hard, friable, slightly sticky and source—welded tuff slightly plastic; common very fine and few Slope range: 2 to 20 percent medium roots; common very fine and fine Elevation: 5,800 to 6,600 feet tubular pores; 45 percent gravel and 5 Average annual precipitation: 12 to 16 inches percent cobbles; mildly alkaline; clear smooth Average annual air temperature: 40 to 44 boundary. degrees F Bk—20 to 44 inches; light gray (10YR 7/2) Frost-free period: 70 to 90 days extremely gravelly sandy loam, grayish brown (10YR 5/2) moist; massive; slightly Taxonomic class: Clayey, montmorillonitic, frigid hard, friable; few very fine and fine roots; few Lithic Ultic Argixerolls Jerome-Twin Falls, Idaho 167

Typical Pedon A1—0 to 1 inch; brown (10YR 5/3) extremely cobbly loam, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; soft, friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine tubular pores; 30 percent gravel, 30 percent cobbles, and 5 percent stones; neutral; clear smooth boundary. A2—1 inch to 3 inches; brown (10YR 5/3) gravelly loam, very dark grayish brown (10YR 3/1) moist; weak fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine tubular pores; 20 percent gravel; neutral; clear smooth boundary. Bt1—3 to 9 inches; brown (10YR 5/3) gravelly clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium subangular Figure 11.—Profile of Brose extremely cobbly loam in blocky structure; hard, firm, sticky and an area of Brose-Amboat complex, 2 to 20 percent slopes. plastic; common very fine and fine roots; many very fine tubular pores; common distinct clay films on faces of peds and in pores; 20 percent gravel; neutral; clear Range in Characteristics smooth boundary. Bt2—9 to 11 inches; brown (10YR 5/3) gravelly Profile: clay, dark brown (10YR 4/3) moist; moderate Depth to bedrock—10 to 20 inches medium subangular blocky structure; very Thickness of mollic epipedon—10 to 18 hard, firm, very sticky and very plastic; inches common very fine and fine roots; common very fine tubular pores; common distinct clay Particle-size control section: films on faces of peds and in pores; 20 Clay content—40 to 60 percent percent gravel; neutral; abrupt smooth Base saturation—60 to 70 percent boundary. Reaction—slightly acid or neutral 2Bt3—11 to 18 inches; reddish brown (5YR 5/3) A1 horizon: gravelly clay, reddish brown (5YR 4/3) moist; Value—2 or 3 moist moderate medium prismatic structure; very Chroma—1 to 3 hard, very firm, very sticky and very plastic; common very fine and fine roots; few very Bt1 horizon: fine tubular pores; many prominent clay Value—4 or 5 dry, 2 or 3 moist films on faces of peds and in pores; 30 Chroma—2 or 3 percent gravel; neutral; abrupt smooth Texture—gravelly loam or gravelly clay boundary. loam 2R—18 inches; dark gray (10YR 4/1) welded tuff, Gravel content—15 to 30 percent black (10YR 2/1) moist; extremely hard; silica Cobble content—0 to 5 percent coatings on rock faces in places. Clay content—25 to 40 percent Bt2 and 2Bt3 horizons: Typical Pedon Location Hue—5YR to 10YR Map unit in which located: Brose-Amboat Value—4 or 5 dry, 3 or 4 moist complex, 2 to 20 percent slopes (fig. 11) Chroma—2 to 4 Location in survey area: About 8 miles south of Gravel content—15 to 30 percent 1 1 1 Rogerson, Idaho; in the NE /4NW /4NW /4 of Cobble content—0 to 5 percent sec. 29, T. 15 S., R. 16 E. Clay content—50 to 70 percent 168 Soil Survey

Budlewis Series brown (10YR 6/4) moist; massive; very hard, firm, sticky and plastic; few very fine Depth class: Moderately deep to a duripan roots; few very fine tubular pores; 5 percent Drainage class: Well drained gravel and 5 percent cobbles; violently Permeability: Slow effervescent (30 percent calcium carbonate Position on landscape: Terraces equivalent); moderately alkaline; abrupt Parent material: Kind—alluvium and residuum; smooth boundary. source—mixed and basalt Bkqm—31 to 36 inches; white (10YR 8/1) Slope range: 2 to 6 percent fractured duripan, very pale brown Elevation: 5,300 to 6,000 feet (10YR 7/3) moist; platy; indurated; 1 Average annual precipitation: 12 to 15 inches extremely hard, extremely firm; many /8- 1 Average annual air temperature: 43 to 46 to /4-inch-thick lime- and silica-cemented degrees F lenses mixed with basalt gravel and Frost-free period: 90 to 100 days cobbles; few very fine and fine roots in 1 fractures of duripan; fractures /4 inch wide Taxonomic class: Fine, montmorillonitic, frigid and 10 inches apart; strongly effervescent; Typic Durixerolls moderately alkaline; abrupt smooth boundary. Typical Pedon 2R—36 inches; dark gray (10YR 4/1) basalt, black (10YR 2/1) moist; lime coating, A—0 to 4 inches; brown (10YR 5/3) silt loam, violently effervescent. very dark grayish brown (10YR 3/2) moist; moderate medium platy structure; slightly Typical Pedon Location hard, friable, slightly sticky and slightly Map unit in which located: Budlewis-Tanner plastic; many very fine to medium roots; complex, 2 to 6 percent slopes many very fine tubular pores; neutral; abrupt Location in survey area: About 20 miles smooth boundary. southwest of Rogerson, Idaho; in the Bt1—4 to 11 inches; grayish brown (10YR 5/2) 1 1 1 SE /4NE /4SE /4 of sec. 24, T. 14 S., R. 12 E. silty clay loam, very dark grayish brown (10YR 3/2) moist; moderate fine angular Range in Characteristics blocky structure; hard, firm, sticky and plastic; common very fine to medium roots; Profile: common very fine tubular pores; many Depth to bedrock—21 to 40 inches distinct clay films on faces of peds and in Depth to duripan—20 to 39 inches pores; neutral; clear smooth boundary. Thickness of mollic epipedon—10 to 14 inches Bt2—11 to 19 inches; pale brown (10YR 6/3) silty Particle-size control section: clay, brown (10YR 4/3) moist; strong medium Clay content—40 to 50 percent prismatic structure; very hard, very firm, very sticky and very plastic; few very fine to A horizon: medium roots; few very fine tubular pores; Value—4 or 5 dry, 2 or 3 moist many prominent clay films on faces of peds Chroma—2 or 3 and in pores; 5 percent gravel; neutral; clear Bt horizon: smooth boundary. Hue—10YR or 7.5YR Btk—19 to 27 inches; very pale brown (10YR 7/3) Value—5 to 7 dry, 3 to 5 moist silty clay loam, brown (10YR 5/3) moist; Chroma—2 to 4 moderate medium angular blocky structure; Texture—silty clay loam, clay, or silty clay very hard, firm, sticky and plastic; few very Clay content—37 to 55 percent fine roots; few very fine tubular pores; Gravel content—0 to 5 percent common faint clay films on faces of peds Cobble content—0 to 5 percent and in pores; 5 percent gravel; strongly Reaction—neutral or mildly alkaline effervescent (16 percent calcium carbonate equivalent); mildly alkaline; abrupt smooth Btk and Bk horizons: boundary. Value—7 or 8 dry, 5 or 6 moist Bk—27 to 31 inches; very pale brown Texture—silty clay loam, clay loam, or gravelly (10YR 8/4) silty clay loam, light yellowish loam Jerome-Twin Falls, Idaho 169

Clay content—24 to 35 percent Bk—22 to 29 inches; very pale brown (10YR 7/3) Gravel content—0 to 20 percent gravelly loam, brown (10YR 5/3) moist; Cobble content—0 to 5 percent massive; hard, friable, slightly sticky and Reaction—mildly alkaline to strongly alkaline slightly plastic; few very fine and fine roots; common very fine tubular pores; 20 percent Bkqm horizon: 1 gravel-sized duripan fragments; violently Thickness of upper silica lamination— /16 to 1 effervescent; strongly alkaline; abrupt wavy inch 1 boundary. Thickness of lower silica laminations— /2 inch to Bkqm—29 to 60 inches; white (10YR 8/2) 3 inches fractured duripan, light gray (10YR 7/2) moist; Cementation between laminations—weak to very massive; extremely hard, extremely firm; strong many continuous silica-cemented laminations throughout duripan; intermittent layers of Chayson Series noncemented material at intervals of 8 to 24 inches; few very fine roots in fractures of Depth class: Moderately deep to a duripan 1 duripan; fractures /4 inch wide and 14 inches Drainage class: Well drained apart; violently effervescent. Permeability: Moderately slow Position on landscape: Terraces Typical Pedon Location Parent material: Kind—alluvium; source—welded Map unit in which located: Budlewis-Chayson tuff, volcanic ash, and flow rock complex, 2 to 6 percent slopes Slope range: 2 to 6 percent Location in survey area: About 23 miles Elevation: 5,300 to 6,000 feet southwest of Rogerson, Idaho; in the Average annual precipitation: 12 to 16 inches 1 1 1 SE /4NW /4SE /4 of sec. 3, T. 15 S., R. 12 E. Average annual air temperature: 41 to 45 degrees F Range in Characteristics Frost-free period: 90 to 100 days Profile: Taxonomic class: Fine-loamy, mixed, frigid Typic Depth to bedrock—45 to 60 inches or more Durixerolls Depth to duripan—20 to 40 inches Thickness of mollic epipedon—10 to 17 inches Typical Pedon Particle-size control section: A—0 to 4 inches; dark grayish brown (10YR 4/2) Clay content—24 to 34 percent loam, very dark brown (10YR 2/2) moist; moderate medium platy structure; slightly A horizon: hard, friable, slightly sticky and slightly Value—4 or 5 dry, 2 or 3 moist plastic; common roots; many very fine and Chroma—2 or 3 fine tubular pores; 10 percent gravel; mildly Gravel content—0 to 10 percent alkaline; clear smooth boundary. Bt horizon: Bt1—4 to 11 inches; grayish brown (10YR 5/2) Value—5 or 6 dry, 2 to 4 moist clay loam, very dark brown (10YR 2/2) moist; Chroma—2 to 4 moderate medium subangular blocky Texture—loam, clay loam, or gravelly loam structure; slightly hard, firm, slightly sticky Gravel content—0 to 10 percent and slightly plastic; common roots; many Cobble content—0 to 5 percent very fine and fine tubular pores; few faint clay films on faces of peds and in pores; mildly Bk horizon: alkaline; abrupt smooth boundary. Value—5 to 7 dry, 4 or 5 moist Bt2—11 to 22 inches; brown (10YR 5/3) clay Chroma—3 or 4 loam, brown (10YR 4/3) moist; moderate Texture—gravelly loam, gravelly clay loam, or medium angular blocky structure; hard, firm, clay loam sticky and plastic; few very fine and fine Gravel content—0 to 20 percent roots; common very fine tubular pores; many Cobble content—0 to 5 percent distinct clay films on faces of peds and in Effervescence—strong or violent pores; mildly alkaline; abrupt smooth Reaction—moderately alkaline or strongly boundary. alkaline 170 Soil Survey

Bkqm horizon: Location in survey area: About 8 miles south of 1 1 1 Value—7 or 8 dry, 6 or 7 moist Twin Falls, Idaho; in the SE /4SE /4SW /4 of Chroma—2 to 4 sec. 31, T. 11 S., R. 17 E. Thickness of duripan—12 to 24 inches Range in Characteristics Chiara Series Profile: Depth to bedrock—more than 60 inches Depth class: Shallow to a duripan Depth to secondary lime—7 to 12 inches Drainage class: Well drained Depth to duripan—10 to 20 inches Permeability: Moderate Position on landscape: Terraces A horizon: Parent material: Kind—alluvium; source—mixed Value—5 or 6 dry, 3 or 4 moist Slope range: 1 to 8 percent Bw horizon: Elevation: 3,600 to 4,500 feet Chroma—3 or 4 Average annual precipitation: 8 to 10 inches Average annual air temperature: 47 to 49 Bkq horizon: degrees F Value—7 or 8 dry, 5 or 6 moist Frost-free period: 120 to 130 days Chroma—2 to 4 Gravel content—0 to 5 percent Taxonomic class: Loamy, mixed, mesic, shallow Durinode content—20 to 40 percent Xerollic Durorthids

Typical Pedon Chuska Series A—0 to 3 inches; pale brown (10YR 6/3) silt Depth class: Shallow to a duripan loam, dark brown (10YR 3/3) moist; weak fine Drainage class: Well drained granular structure; soft, friable; many very Permeability: Moderately slow fine, fine, and medium roots; many very fine Position on landscape: Ridges, terraces, and dip and fine tubular pores; neutral; clear smooth slopes boundary. Parent material: Kind—alluvium; source—welded Bw—3 to 9 inches; light yellowish brown (10YR tuff 6/4) silt loam, brown (10YR 4/3) moist; weak Slope range: 1 to 12 percent medium subangular blocky structure; slightly Elevation: 3,500 to 5,700 feet hard, friable; many very fine, fine, and Average annual precipitation: 9 to 12 inches medium roots; many very fine and fine Average annual air temperature: 46 to 51 tubular pores; 5 percent durinodes; mildly degrees F alkaline; clear smooth boundary. Frost-free period: 100 to 140 days Bkq—9 to 17 inches; white (10YR 8/2) silt loam, Taxonomic class: Loamy, mixed, mesic, shallow pale brown (10YR 6/3) moist; massive; hard, Xerollic Durargids firm; common very fine and fine roots; common very fine and fine tubular pores; 20 Typical Pedon percent durinodes; 5 percent gravel-sized duripan fragments; strongly effervescent (19 A—0 to 3 inches; pale brown (10YR 6/3) gravelly percent calcium carbonate equivalent); loam, dark brown (10YR 4/3) moist; weak moderately alkaline; abrupt smooth boundary. medium platy structure; soft, friable, slightly Bkqm—17 to 49 inches; white (10YR 8/2) sticky and slightly plastic; common roots; fractured indurated duripan, pale brown (10YR many very fine and fine vesicular pores; 25 6/3) moist; massive; extremely hard, percent gravel; moderately alkaline; abrupt extremely firm; many continuous silica- smooth boundary. cemented laminations throughout duripan; Bt1—3 to 7 inches; pale brown (10YR 6/3) clay violently effervescent. loam, dark brown (10YR 4/3) moist; moderate medium subangular blocky structure; slightly Typical Pedon Location hard, friable, sticky and plastic; common very Map unit in which located: Chiara silt loam, 1 to 8 fine to medium roots; many very fine and fine percent slopes tubular pores; common distinct clay films on Jerome-Twin Falls, Idaho 171

faces of peds and in pores; 10 percent gravel; 3R—51 inches; light yellowish brown (10YR 6/4) moderately alkaline; abrupt smooth boundary. welded tuff, yellowish brown (10YR 5/4) Bt2—7 to 10 inches; pale brown (10YR 5/3) clay moist; extremely hard; coating of lime on loam, dark brown (10YR 4/3) moist; moderate upper boundary. medium subangular blocky structure; hard, Typical Pedon Location firm, sticky and plastic; few very fine and fine roots; common very fine and fine tubular Map unit in which located: Chuska gravelly loam, pores; common distinct clay films on faces of 2 to 12 percent slopes peds and in pores; 10 percent gravel-sized Location in survey area: About 8 miles south duripan fragments; moderately alkaline; of Rogerson, Idaho; in the 1 1 1 abrupt smooth boundary. SW /4SE /4SW /4 of sec. 10, T. 15 S., Btk—10 to 14 inches; very pale brown (10YR 7/4) R. 15 E. gravelly clay loam, yellowish brown (10YR 5/4) moist; moderate medium subangular Range in Characteristics blocky structure; hard, firm, sticky and Profile: plastic; few very fine and fine roots; common Depth to bedrock—40 to 60 inches or more very fine tubular pores; common faint clay Depth to duripan—12 to 20 inches films on faces of peds and in pores; 25 percent gravel-sized duripan fragments; Particle-size control section: violently effervescent (20 percent calcium Clay content—26 to 34 percent carbonate equivalent); strongly alkaline; A horizon: abrupt smooth boundary. Value—5 or 6 dry, 3 or 4 moist Bkqm—14 to 18 inches; white (10YR 8/2) Chroma—2 or 3 fractured indurated duripan, light yellowish brown (10YR 6/4) moist; massive; extremely Bt horizon: hard, extremely firm; many continuous silica- Value—5 or 6 dry, 3 or 4 moist cemented laminations throughout duripan; Chroma—2 to 4 few very fine roots in fractures of duripan; Texture—clay loam, loam, gravelly clay loam, or 1 fractures /4 inch wide and 10 inches apart; gravelly loam violently effervescent; abrupt smooth Gravel content—5 to 25 percent boundary. Effervescence—slight to strong 2Bkq—18 to 29 inches; very pale brown (10YR Bkqm horizon: 7/3) extremely gravelly sandy loam, light Thickness of upper silica lamination—1 inch to 3 yellowish brown (10YR 6/4) moist; massive; inches very hard, very firm; few very fine and fine 1 Thickness of lower silica laminations— /2 inch to roots; few very fine and fine tubular pores; 50 2 inches percent gravel and 20 percent gravel-sized duripan fragments; coatings of lime on gravel and pendants of lime on underside of gravel; Colthorp Series weakly cemented matrix; violently Depth class: Shallow to a duripan effervescent (25 percent calcium carbonate Drainage class: Well drained equivalent); strongly alkaline; abrupt wavy Permeability: Moderately slow boundary. Position on landscape: Terraces 2Bk—29 to 51 inches; very pale brown (10YR Parent material: Kind—alluvium; source—mixed 7/4) extremely gravelly sandy loam, yellowish Slope range: 1 to 15 percent brown (10YR 5/4) moist; massive; slightly Elevation: 4,200 to 4,700 feet hard, friable; few very fine roots; few very fine Average annual precipitation: 9 to 10 tubular pores; 60 percent gravel and 15 inches percent cobbles; coatings of lime on rock Average annual air temperature: 49 to 51 fragments and pendants of lime on degrees F undersides of rock fragments; violently Frost-free period: 110 to 120 days effervescent (25 percent calcium carbonate equivalent); moderately alkaline; abrupt Taxonomic class: Loamy, mixed, mesic, shallow smooth boundary. Xerollic Durargids 172 Soil Survey

Typical Pedon Range in Characteristics A—0 to 3 inches; pale brown (10YR 6/3) cobbly Profile: silt loam, dark brown (10YR 3/3) moist; Depth to bedrock—20 to 40 inches moderate medium platy structure; slightly Depth to secondary lime—5 to 14 inches hard, friable; many very fine, fine, and Depth to duripan—10 to 20 inches medium roots; many very fine and fine A horizon: tubular pores; 10 percent gravel and 10 Value—5 or 6 dry, 3 or 4 moist percent cobbles; neutral; clear smooth Chroma—2 or 3 boundary. Bt—3 to 8 inches; very pale brown (10YR 7/3) silt Bt horizon: loam, brown (10YR 4/3) moist; moderate Value—5 to 7 dry, 3 to 5 moist medium subangular blocky structure; slightly Chroma—2 to 4 hard, friable, slightly sticky and slightly Texture—silt loam or silty clay loam plastic; common very fine and fine roots; Clay content—20 to 30 percent common very fine and fine tubular pores; few Gravel content—0 to 10 percent faint clay films on faces of peds and in pores; Cobble content—0 to 5 percent 10 percent gravel; neutral; clear smooth Bkq horizon: boundary. Value—6 to 8 dry, 4 to 6 moist Btk—8 to 11 inches; very pale brown (10YR 7/3) Chroma—2 to 4 silt loam, yellowish brown (10YR 5/4) moist; Texture—gravelly silt loam, gravelly loam, or silt moderate medium subangular blocky loam structure; hard, friable, slightly sticky and Gravel content—0 to 30 percent slightly plastic; common very fine and fine roots; common very fine and fine tubular pores; few faint clay films on faces of peds Congle Series and in pores; 10 percent gravel; slightly Depth class: Very deep effervescent in places; mildly alkaline; clear Drainage class: Well drained smooth boundary. Permeability: Moderately slow Bkq—11 to 18 inches; very pale brown (10YR Position on landscape: Foot slopes and back 8/3) gravelly silt loam, light yellowish brown slopes (10YR 6/4) moist; weak medium subangular Parent material: Kind—colluvium; source—welded blocky structure; very hard, firm; common tuff and volcanic ash very fine and fine roots; common fine and Slope range: 8 to 30 percent very fine tubular pores; 10 percent durinodes; Elevation: 4,800 to 6,400 feet 25 percent gravel-sized duripan fragments; Average annual precipitation: 13 to 20 inches strongly effervescent (18 percent calcium Average annual air temperature: 42 to 45 carbonate equivalent); moderately alkaline; degrees F abrupt smooth boundary. Frost-free period: 80 to 100 days Bkqm—18 to 24 inches; white (10YR 8/2) indurated duripan, light yellowish brown Taxonomic class: Fine-loamy, mixed, frigid (10YR 6/4) moist; massive; extremely hard, Pachic Ultic Haploxerolls extremely firm; many continuous silica- Typical Pedon cemented laminations throughout duripan; violently effervescent; abrupt wavy A—0 to 4 inches; dark brown (10YR 4/3) gravelly boundary. loam, black (10YR 2/1) moist; weak fine platy 2R—24 inches; basalt. structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine Typical Pedon Location roots; many very fine and fine tubular pores; Map unit in which located: Colthorp cobbly silt 15 percent gravel; neutral; clear smooth loam, 1 to 4 percent slopes boundary. Location in survey area: About 1 mile south of Bw1—4 to 11 inches; dark brown (10YR 3/3) 1 1 1 Hollister, Idaho; in the SE /4NW /4NW /4 of gravelly loam, very dark brown (10YR 2/2) sec. 34, T. 12 S., R. 16 E. moist; moderate medium subangular blocky Jerome-Twin Falls, Idaho 173

structure; slightly hard, friable, slightly sticky Permeability: Moderately slow and slightly plastic; many very fine and fine Position on landscape: Hill slopes and breaks roots; many very fine tubular pores; 15 Parent material: Kind—colluvium; source—welded percent gravel; neutral; clear smooth tuff and volcanic ash boundary. Slope range: 4 to 75 percent Bw2—11 to 42 inches; dark brown (10YR 3/3) Elevation: 5,800 to 7,600 feet gravelly clay loam, black (10YR 2/1) moist; Average annual precipitation: 20 to 25 inches moderate medium subangular blocky Average annual air temperature: 40 to 42 structure; hard, firm, sticky and plastic; degrees F common very fine and fine roots; common Frost-free period: 20 to 60 days very fine and fine tubular pores; 15 percent Taxonomic class: Fine-loamy, mixed Argic Pachic gravel; neutral; abrupt smooth boundary. Cryoborolls Bw3—42 to 62 inches; light yellowish brown (10YR 6/4) gravelly clay loam, dark brown Typical Pedon (10YR 4/3) moist; moderate medium A—0 to 6 inches; very dark grayish brown (10YR subangular blocky structure; hard, firm, 3/2) gravelly loam, very dark brown (10YR sticky and plastic; very few fine and fine 2/2) moist; weak fine granular structure; roots; common very fine tubular pores; 25 slightly hard, friable, slightly sticky and percent gravel; neutral. slightly plastic; many roots; many very fine and fine tubular pores; 25 percent gravel; Typical Pedon Location moderately acid; clear smooth boundary. Map unit in which located: Congle gravelly loam, Bt1—6 to 15 inches; dark grayish brown (10YR 8 to 30 percent slopes 4/2) gravelly loam, very dark grayish brown Location in survey area: About 12 miles east of (10YR 3/2) moist; moderate medium 1 1 1 Hollister, Idaho; in the SW /4SW /4NE /4 of subangular blocky structure; slightly hard, sec. 34, T. 12 S., R. 18 E. friable, slightly sticky and slightly plastic; many roots; many fine and very fine tubular Range in Characteristics pores; common faint clay films on faces of Profile: peds and in pores; 25 percent gravel; slightly Depth to welded tuff or volcanic ash—more than acid; gradual wavy boundary. 60 inches Bt2—15 to 30 inches; brown (10YR 4/3) gravelly Thickness of mollic epipedon—20 to 42 inches loam, dark brown (10YR 3/3) moist; moderate Rock fragment content—5 to 30 percent medium subangular blocky structure; hard, Base saturation—60 to 70 percent in upper 30 firm, slightly sticky and slightly plastic; inches common roots; many fine and very fine Reaction—neutral or slightly acid tubular pores; common faint clay films on faces of peds and in pores; 25 percent Particle-size control section: gravel; moderately acid; clear smooth Clay content—28 to 35 percent boundary. A horizon: Bt3—30 to 65 inches; brown (10YR 5/3) gravelly Value—3 or 4 dry, 2 or 3 moist clay loam, dark brown (10YR 3/3) moist; Chroma—1 to 3 moderate medium angular blocky structure; hard, firm, sticky and plastic; common very Bw horizon: fine and fine roots; common very fine and Value—3 to 6 dry, 2 or 3 moist fine tubular pores; many distinct clay films on Chroma—1 to 4 faces of peds and in pores; 20 percent Texture—clay loam, gravelly clay loam, gravelly gravel; moderately acid; abrupt smooth loam, or gravelly silty clay loam boundary. 2C—65 to 70 inches; yellowish brown (10YR 5/4) Dehana Series silty clay loam, dark yellowish brown (10YR 4/6) moist; massive; hard, firm, sticky and Depth class: Very deep plastic; few very fine roots; few very fine Drainage class: Well drained tubular pores; moderately acid. 174 Soil Survey

Typical Pedon Location Typical Pedon Map unit in which located: Dehana-Rock outcrop A—0 to 4 inches; pale brown (10YR 6/3) silt complex, 4 to 40 percent slopes loam, dark brown (10YR 3/3) moist; moderate Location in survey area: About 22 miles medium platy structure; soft, friable; many southwest of Rogerson, Idaho; in the very fine and fine roots; common very fine 1 1 1 SW /4NE /4NE /4 of sec. 16, T. 16 S., R. 13 E. and fine tubular pores; neutral; gradual wavy boundary. Range in Characteristics BA—4 to 14 inches; pale brown (10YR 6/3) silt loam, brown (10YR 4/3) moist; weak medium Profile: subangular blocky structure; slightly hard, Depth to welded tuff or volcanic ash—more than friable, slightly sticky and slightly plastic; 60 inches many very fine and fine roots; common Thickness of mollic epipedon—35 to 65 inches fine tubular pores; neutral; gradual wavy Particle-size control section: boundary. Rock fragment content—20 to 35 percent Bw—14 to 21 inches; pale brown (10YR 6/3) silt Clay content—20 to 30 percent loam, brown (10YR 4/3) moist; moderate Base saturation—60 to 70 percent medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; A horizon: common very fine and fine roots; common Value—3 or 4 dry, 2 or 3 moist fine tubular pores; slightly effervescent (8 Chroma—1 or 2 percent calcium carbonate equivalent); mildly Gravel content—15 to 30 percent alkaline; clear smooth boundary. Reaction—slightly acid or moderately acid 2Bkq—21 to 27 inches; light gray (10YR 7/2) Bt1 and Bt2 horizons: loam, grayish brown (10YR 5/2) moist; Value—3 to 5 dry, 2 to 4 moist massive; very hard, firm, slightly sticky and Chroma—1 to 3 slightly plastic; few very fine roots; few fine Texture—gravelly loam or gravelly clay loam tubular pores; 10 percent durinodes; 10 Gravel content—20 to 25 percent percent gravel-sized duripan fragments; Cobble content—0 to 10 percent strongly effervescent (34 percent calcium Reaction—slightly acid or moderately acid carbonate equivalent); mildly alkaline; abrupt smooth boundary. Bt3 horizon: 1 2Bkqm—27 to 45 inches; fractured duripan; /4- to Value—5 or 6 dry, 3 or 4 moist 3-inch-thick silica lenses throughout; Chroma—2 to 4 extremely hard, platy, rocklike material; Texture—gravelly clay loam or cobbly loam gradual wavy boundary. Gravel content—15 to 20 percent 3Bk—45 to 61 inches; multicolored sand and Cobble content—0 to 15 percent gravel; single grain; loose, very friable; strongly effervescent (8 percent calcium Dolman Series carbonate equivalent); moderately alkaline. Depth class: Moderately deep to a duripan Typical Pedon Location Drainage class: Well drained Map unit in which located: Dolman silt loam, 1 to Permeability: Moderate 4 percent slopes Position on landscape: Terraces Location in survey area: About 17 miles Parent material: Kind—old alluvium; source— northwest of Buhl, Idaho; in the mixed 1 1 1 SW /4SE /4SE /4 of sec. 35, T. 7 S., R. 12 E. Slope range: 1 to 4 percent Elevation: 3,000 to 4,000 feet Range in Characteristics Average annual precipitation: 8 to 10 inches Average annual air temperature: 47 to 49 Profile: degrees F Depth to bedrock—more than 60 inches Frost-free period: 120 to 140 days Depth to secondary lime—14 to 24 inches Depth to duripan—20 to 40 inches Taxonomic class: Coarse-silty, mixed, mesic Xerollic Durorthids Particle-size control section: Jerome-Twin Falls, Idaho 175

Gravel content—0 to 10 percent slightly hard, friable, slightly sticky and Clay content—12 to 17 percent slightly plastic; many very fine and fine roots; many very fine and fine tubular pores; 50 A horizon: percent gravel; neutral; clear smooth Value—5 or 6 dry boundary. Chroma—2 or 3 Bw3—21 to 36 inches; yellowish brown (10YR Gravel content—0 to 10 percent 5/4) extremely gravelly clay loam, dark brown Bw horizon: (10YR 4/3) moist; weak medium subangular Value—3 or 4 moist blocky structure; hard, friable, sticky and Gravel content—0 to 5 percent plastic; common very fine and fine roots; Clay content—16 to 24 percent many very fine and fine tubular pores; 70 Calcium carbonate equivalent—0 to 5 percent percent gravel; neutral; gradual wavy boundary. 2Bkq horizon: C—36 to 65 inches; brown (10YR 5/3) extremely Value—6 to 8 dry, 4 to 6 moist gravelly clay loam, very dark grayish brown Chroma—2 to 4 (10YR 3/2) moist; massive; slightly hard, Texture—very fine sandy loam, loam, or silt loam friable, sticky and plastic; common very fine Calcium carbonate equivalent—15 to 35 percent and fine roots; common very fine tubular pores; 70 percent gravel; neutral. Doodlelink Series Typical Pedon Location Depth class: Very deep Map unit in which located: Doodlelink very Drainage class: Well drained gravelly loam, 30 to 75 percent slopes Permeability: Moderately slow Location in survey area: About 14 miles east of Position on landscape: Breaks 1 1 1 Rogerson, Idaho; in the SE /4SE /4SE /4 of Parent material: Kind—colluvium; source—welded sec. 36, T. 12 S., R. 18 E. tuff and volcanic ash Slope range: 8 to 75 percent Range in Characteristics Elevation: 4,800 to 6,400 feet Profile: Average annual precipitation: 14 to 18 inches Depth to welded tuff or volcanic ash—more than Average annual air temperature: 42 to 45 60 inches degrees F Thickness of mollic epipedon—20 to 30 inches Frost-free period: 80 to 100 days Rock fragment content—40 to 80 percent Taxonomic class: Loamy-skeletal, mixed, frigid Base saturation—55 to 65 percent in upper 30 Pachic Ultic Haploxerolls inches Particle-size control section: Typical Pedon Clay content—20 to 30 percent A—0 to 6 inches; dark grayish brown (10YR 4/2) A and Bw1 horizons: very gravelly loam, black (10YR 2/1) moist; Value—3 to 5 dry, 2 or 3 moist weak fine granular structure; soft, very Chroma—1 to 3 friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine Bw2 and Bw3 horizons: and fine tubular pores; 50 percent gravel; Value—4 to 6 dry, 3 or 4 moist neutral; gradual wavy boundary. Chroma—1 to 3 Bw1—6 to 12 inches; dark brown (10YR 4/3) very Texture—very gravelly sandy loam, extremely gravelly loam, black (10YR 2/1) moist; weak gravelly loam, or extremely gravelly clay fine subangular blocky structure; slightly loam hard, friable, slightly sticky and slightly plastic; many very fine and fine roots; many Eep Series very fine and fine tubular pores; 50 percent gravel; neutral; clear smooth boundary. Depth class: Very deep Bw2—12 to 21 inches; brown (10YR 5/3) very Drainage class: Well drained gravelly loam, dark brown (10YR 3/3) moist; Permeability: Moderate weak fine subangular blocky structure; Position on landscape: Breaks and hill slopes 176 Soil Survey

Parent material: Kind—colluvium; source— Typical Pedon Location volcanic ash and welded tuff Map unit in which located: Eep very cobbly sandy Slope range: 6 to 75 percent loam, 6 to 35 percent slopes Elevation: 5,800 to 6,800 feet Location in survey area: About 21 miles Average annual precipitation: 16 to 22 inches southwest of Rogerson, Idaho; in the Average annual air temperature: 40 to 44 1 1 1 NE /4SE /4SE /4 of sec. 7, T. 15 S., R. 13 E. degrees F Frost-free period: 60 to 100 days Range in Characteristics Taxonomic class: Ashy-skeletal, frigid Vitrandic Profile: Argixerolls Depth to bedrock—more than 60 inches Thickness of mollic epipedon—10 to 20 inches Typical Pedon Rock fragment content—40 to 70 percent A—0 to 9 inches; dark grayish brown (10YR 4/2) Base saturation—65 to 75 percent in upper 40 very cobbly sandy loam, very dark brown inches (10YR 2/2) moist; weak medium granular Particle-size control section: structure; soft, friable; many roots; many very Clay content—20 to 30 percent fine tubular pores; 20 percent gravel, 30 percent cobbles, and 5 percent stones; A horizon: neutral; gradual wavy boundary. Chroma—1 or 2 Bt1—9 to 17 inches; brown (10YR 5/3) very Reaction—slightly acid or neutral gravelly clay loam, very dark grayish brown Volcanic glass content—75 to 85 percent (10YR 3/2) moist; moderate medium Bt horizon: subangular blocky structure; slightly hard, Value—4 or 5 dry, 2 or 3 moist friable, sticky and plastic; many roots; many Chroma—2 or 3 very fine tubular pores; common distinct clay Texture—very gravelly clay loam, very cobbly films on faces of peds and in pores; 40 loam, or very gravelly loam percent gravel and 15 percent cobbles; Gravel content—25 to 40 percent slightly acid; gradual wavy boundary. Cobble content—10 to 20 percent Bt2—17 to 26 inches; brown (10YR 5/3) very Stone content—0 to 10 percent gravelly loam, dark brown (10YR 3/3) moist; Volcanic glass content—65 to 85 percent moderate medium subangular blocky Reaction—slightly acid or neutral structure; slightly hard, friable, slightly sticky and slightly plastic; many roots; many very BC horizon: fine tubular pores; few faint clay films on Value—5 to 8 dry, 3 to 7 moist faces of peds and in pores; 40 percent Chroma—1 to 4 gravel, 20 percent cobbles, and 5 percent Texture—very cobbly sandy loam, very gravelly stones; neutral; gradual wavy boundary. sandy loam, or extremely gravelly sandy BC—26 to 38 inches; pale brown (10YR 6/3) very loam cobbly sandy loam, brown (10YR 4/3) moist; Gravel content—30 to 60 percent massive; slightly hard, friable; common very Cobble content—10 to 30 percent fine to medium roots; many very fine Volcanic glass content—85 to 95 percent tubular pores; 30 percent gravel and 20 percent cobbles; neutral; clear wavy Elhina Series boundary. C—38 to 76 inches; white (10YR 8/1) Depth class: Moderately deep to a duripan unconsolidated loamy sand volcanic ash, Drainage class: Well drained light gray (10YR 7/2) moist; single grain; Permeability: Slow loose; few very fine roots; abrupt wavy Position on landscape: Terraces boundary. Parent material: Kind—alluvium; source—welded Cr—76 to 78 inches; very pale brown (10YR 7/3) tuff consolidated volcanic ash, light yellowish Slope range: 2 to 6 percent brown (10YR 6/4) moist; massive; very hard, Elevation: 5,200 to 5,800 feet very firm. Average annual precipitation: 9 to 11 inches Jerome-Twin Falls, Idaho 177

Average annual air temperature: 43 to 45 sand, dark yellowish brown (10YR 3/6) moist; degrees F massive; slightly hard, very friable; few very Frost-free period: 85 to 95 days fine roots; 70 percent gravel; slightly effervescent; moderately alkaline. Taxonomic class: Fine, montmorillonitic, frigid Abruptic Xerollic Durargids Typical Pedon Location Typical Pedon Map unit in which located: Elhina very gravelly loam, 2 to 6 percent slopes A—0 to 1 inch; grayish brown (10YR 5/2) very Location in survey area: About 14 miles south of gravelly loam, very dark grayish brown (10YR 1 1 1 Salmon Falls Dam; in the NE /4SW /4NE /4 of 3/2) moist; moderate fine granular structure; sec. 22, T. 16 S., R. 14 E. soft, very friable, slightly sticky and slightly plastic; many roots; many very fine tubular Range in Characteristics pores; 35 percent gravel; neutral; abrupt Profile: smooth boundary. Depth to bedrock—more than 60 inches E—1 inch to 3 inches; light brownish gray (10YR Depth to duripan—20 to 40 inches 6/2) gravelly clay loam, dark brown (10YR 3/3) moist; moderate medium platy structure; Particle-size control section: hard, firm, sticky and plastic; many roots; Clay content—36 to 50 percent many fine vesicular pores; 20 percent gravel; A horizon: slightly acid; abrupt smooth boundary. Value—2 or 3 moist Bt1—3 to 8 inches; brown (10YR 5/3) clay, dark Chroma—2 or 3 brown (10YR 4/3) moist; strong fine angular blocky structure; hard, firm, very sticky and E horizon: very plastic; few very fine roots; few very fine Chroma—2 or 3 tubular pores; many prominent clay films on Texture—gravelly clay loam or gravelly loam faces of peds and in pores; 5 percent gravel; Gravel content—20 to 30 percent neutral; clear smooth boundary. Clay content—20 to 30 percent Bt2—8 to 12 inches; light yellowish brown (10YR Bt horizon: 6/4) clay, yellowish brown (10YR 5/4) moist; Value—5 or 6 dry, 3 to 5 moist strong medium angular blocky structure; very Chroma—2 to 4 hard, very firm, very sticky and very plastic; Texture—clay, gravelly clay, or gravelly clay few very fine roots; few very fine tubular loam pores; many prominent clay films on faces of Gravel content—5 to 30 percent peds and in pores; 10 percent gravel; neutral; Clay content—36 to 50 percent abrupt smooth boundary. Reaction—slightly acid or neutral 2Bk—12 to 21 inches; pale brown (10YR 6/3) extremely gravelly loam, yellowish brown 2Bkqm horizon: (10YR 5/4) moist; massive; very hard, very Thickness of upper silica lamination—1 inch to 3 firm, slightly sticky and slightly plastic; few inches 1 very fine roots; few very fine tubular pores; 70 Thickness of lower silica laminations— /8 inch to percent gravel; strongly effervescent; 3 inches moderately alkaline; abrupt smooth boundary. Thickness of duripan—10 to 24 inches 2Bkqm—21 to 32 inches; white (10YR 8/1) fractured indurated duripan, very pale brown Elijah Series (10YR 7/3) moist; massive; extremely hard, 1 extremely firm; many /8-inch-thick silica- Depth class: Moderately deep to a duripan cemented laminations throughout duripan; Drainage class: Well drained few very fine roots in fractures of duripan; Permeability: Moderately slow 1 fractures /4 inch wide and 10 inches apart; Position on landscape: Terraces violently effervescent; moderately alkaline; Parent material: Kind—alluvium; source—mixed abrupt smooth boundary. Slope range: 1 to 6 percent 2Bkq—32 to 60 inches; brownish yellow (10YR Elevation: 4,600 to 5,200 feet 6/6) weakly cemented extremely gravelly Average annual precipitation: 8 to 11 inches 178 Soil Survey

Average annual air temperature: 46 to 48 Range in Characteristics degrees F Profile: Frost-free period: 100 to 120 days Depth to bedrock—more than 60 inches Taxonomic class: Fine-silty, mixed, mesic Depth to duripan—20 to 40 inches Xerollic Durargids Particle-size control section: Typical Pedon Clay content—26 to 35 percent A—0 to 3 inches; pale brown (10YR 6/3) silt A horizon: loam, very dark grayish brown (10YR 3/2) Value—5 or 6 dry, 3 or 4 moist moist; weak medium platy structure; slightly Chroma—2 or 3 hard, very friable, slightly sticky and slightly Gravel content—0 to 5 percent plastic; many roots; many very fine and Reaction—neutral or mildly alkaline fine tubular pores; neutral; clear smooth Bt horizon: boundary. Value—5 to 7 dry, 3 to 5 moist Bt1—3 to 7 inches; pale brown (10YR 6/3) silty Chroma—2 to 4 clay loam, dark brown (10YR 3/3) moist; Texture—silt loam or silty clay loam weak medium subangular blocky structure; Reaction—neutral or mildly alkaline hard, firm, sticky and plastic; many roots; many very fine tubular pores; common faint Bk horizon: clay films on faces of peds and in pores; Value—7 or 8 dry, 5 or 6 moist neutral; clear smooth boundary. Chroma—3 or 4 Bt2—7 to 14 inches; pale brown (10YR 6/3) silty Texture—loam or silt loam clay loam, brown (10YR 4/3) moist; moderate Gravel content—0 to 5 percent medium subangular blocky structure; hard, Clay content—12 to 18 percent firm, sticky and plastic; common very fine Bkqm horizon: and fine roots; common very fine tubular Thickness of upper silica lamination—1 inch to 3 pores; common faint clay films on faces of inches peds and in pores; neutral; abrupt smooth Thickness of lower silica laminations—1 inch to 8 boundary. inches Bk—14 to 38 inches; very pale brown (10YR 7/3) Cementation between laminations—weak to loam, brown (10YR 5/3) moist; massive; hard, strong firm, slightly sticky and slightly plastic; few Thickness of duripan—20 to 40 inches very fine roots; few very fine tubular pores; violently effervescent (17 percent calcium carbonate equivalent); mildly alkaline; abrupt Emberton Series smooth boundary. Depth class: Moderately deep to basalt Bkqm—38 to 60 inches; white (10YR 8/2) Drainage class: Somewhat excessively drained fractured duripan, light gray (10YR 7/2) moist; Permeability: Moderately rapid platy; indurated; extremely hard, extremely Position on landscape: Terraces firm; many 1- to 3-inch-thick lime-and silica- Parent material: Kind—wind-modified alluvium; cemented lenses with weakly cemented source—mixed sandy loam between lenses; duripan massive Slope range: 1 to 6 percent at at depth of 52 inches; few very fine roots 1 3 Elevation: 3,500 to 4,000 feet in fractures of duripan; fractures /8 to /4 inch Average annual precipitation: 9 to 10 inches wide and 8 inches apart; violently Average annual air temperature: 50 to 52 effervescent; moderately alkaline. degrees F Typical Pedon Location Frost-free period: 130 to 140 days Map unit in which located: Elijah-Pigtail complex, Taxonomic class: Sandy, mixed, mesic Xeric 1 to 6 percent slopes Torriorthents Location in survey area: About 18 miles west Typical Pedon of Rogerson, Idaho; in the 1 1 1 SW /4SW /4NW /4 of sec. 28, T. 13 S., A—0 to 8 inches; yellowish brown (10YR 5/4) R. 13 E. loamy fine sand, dark brown (10YR 3/3) Jerome-Twin Falls, Idaho 179

moist; single grain; loose; common roots; Average annual air temperature: 49 to 51 many very fine irregular pores; slightly acid; degrees F gradual wavy boundary. Frost-free period: 130 to 140 days C1—8 to 32 inches; yellowish brown (10YR 5/4) Taxonomic class: Sandy, mixed, mesic Xerollic loamy fine sand, brown (10YR 4/3) moist; Calciorthids massive; loose; common roots; many very fine irregular pores; slightly acid; clear wavy Typical Pedon boundary. A—0 to 9 inches; brown (10YR 5/3) loamy fine 2C2—32 to 39 inches; pale brown (10YR 6/3) fine sand, very dark grayish brown (10YR 3/2) sandy loam, yellowish brown (10YR 5/4) moist; weak medium platy structure; soft, moist; massive; slightly hard, friable; few very very friable; many very fine roots and fine and fine roots; common very fine and common fine roots; moderately alkaline; fine tubular pores; 5 percent gravel; mildly abrupt smooth boundary. alkaline; abrupt smooth boundary. Bw—9 to 26 inches; pale brown (10YR 6/3) loamy 3R—39 inches; basalt. fine sand, very dark grayish brown (10YR 4/2) moist; weak coarse subangular blocky Typical Pedon Location structure; soft, very friable; common very fine Map unit in which located: Kecko-Emberton roots; moderately alkaline; abrupt wavy complex, 1 to 6 percent slopes boundary. Location in survey area: About 9 miles northeast Bk—26 to 60 inches; pale brown (10YR 6/3) 1 1 1 of Twin Falls, Idaho; in the SW /4SW /4NE /4 of loamy fine sand, dark grayish brown (10YR sec. 23, T. 9 S., R. 18 E. 4/2) moist; massive; soft, very friable; common very fine roots; strongly Range in Characteristics effervescent (8 percent calcium carbonate equivalent); strongly alkaline. Profile: Depth to bedrock—20 to 40 inches Typical Pedon Location Particle-size control section: Map unit in which located: Fathom loamy fine Clay content—5 to 10 percent sand, 0 to 12 percent slopes Location in survey area: About 3.5 miles north of A and C horizons: 1 1 1 Kimberly, Idaho; in the SW /4SE /4NW /4 of Value—5 or 6 dry, 3 or 4 moist sec. 4, T. 10 S., R. 18 E. Chroma—2 to 4 Reaction—slightly acid or neutral Range in Characteristics 2C2 horizon: Profile: Value—6 or 7 dry Depth to bedrock—more than 60 inches Chroma—2 to 4 Depth to secondary lime—15 to 27 inches Texture—fine sandy loam or sandy loam Gravel content—0 to 10 percent Particle-size control section: Reaction—neutral or mildly alkaline Clay content—0 to 5 percent A horizon: Fathom Series Value—5 or 6 dry, 3 or 4 moist Chroma—2 or 3 Depth class: Very deep Drainage class: Somewhat excessively Bw and Bk horizons: drained Value—5 to 7 dry, 4 or 5 moist Permeability: Rapid Chroma—2 or 3 Position on landscape: Alluvial fans, terraces, Texture—loamy fine sand or loamy sand and breaks Parent material: Kind—wind-modified alluvium; Flatron Series source—mixed Slope range: 0 to 60 percent Depth class: Shallow to welded tuff Elevation: 3,000 to 3,700 feet Drainage class: Well drained Average annual precipitation: 8 to 10 inches Permeability: Slow 180 Soil Survey

Position on landscape: Ridges and dip slopes Thickness of mollic epipedon—10 to 20 inches Parent material: Kind—residuum; source—welded Particle-size control section: tuff Clay content—36 to 50 percent Slope range: 2 to 20 percent Elevation: 5,000 to 5,700 feet A horizon: Average annual precipitation: 14 to 16 inches Value—2 or 3 moist Average annual air temperature: 45 to 48 Chroma—2 or 3 degrees F Gravel content—25 to 40 percent Frost-free period: 100 to 110 days Cobble content—5 to 10 percent Stone content—5 to 10 percent Taxonomic class: Clayey-skeletal, montmorillonitic, mesic Lithic Argixerolls Bt horizon: Chroma—2 or 3 Typical Pedon Texture—very gravelly clay loam, very cobbly A—0 to 4 inches; grayish brown (10YR 5/2) very clay, extremely cobbly clay loam, or gravelly loam, very dark grayish brown (10YR extremely gravelly clay 3/2) moist; weak fine granular structure; soft, Gravel content—20 to 40 percent very friable, slightly sticky and slightly Cobble content—20 to 25 percent plastic; many roots; many very fine tubular Stone content—5 to 15 percent pores; 25 percent gravel, 5 percent cobbles, and 5 percent stones; neutral; abrupt smooth Forvic Series boundary. Bt1—4 to 6 inches; brown (10YR 5/3) very cobbly Depth class: Moderately deep to a duripan clay loam, brown (10YR 3/3) moist; moderate Drainage class: Well drained medium subangular blocky structure; hard, Permeability: Slow friable, sticky and plastic; many roots; Position on landscape: Terraces common very fine tubular pores; common Parent material: Kind—alluvium and colluvium; distinct clay films on faces of peds and in source—welded tuff pores; 25 percent gravel, 20 percent cobbles, Slope range: 2 to 6 percent and 5 percent stones; neutral; clear smooth Elevation: 5,800 to 6,200 feet boundary. Average annual precipitation: 16 to 18 inches Bt2—6 to 12 inches; brown (10YR 5/3) extremely Average annual air temperature: 41 to 43 gravelly clay, dark brown (10YR 3/3) moist; degrees F strong medium subangular blocky structure; Frost-free period: 80 to 90 days hard, firm, sticky and plastic; few very fine Taxonomic class: Fine, montmorillonitic, frigid and fine roots; few very fine tubular pores; Typic Durixerolls common distinct clay films on faces of peds and in pores; 35 percent gravel, 20 percent Typical Pedon cobbles, and 10 percent stones; thin carbonate coating on underside of welded tuff A—0 to 7 inches; dark grayish brown (10YR 4/2) fragments; mildly alkaline; abrupt smooth silty clay loam, black (10YR 2/1) moist; boundary. moderate medium platy structure; soft, R—12 inches; gray (10YR 6/1) welded tuff, dark friable, slightly sticky and slightly plastic; gray (10YR 4/1) moist. many very fine and fine roots; many very fine and fine tubular pores; 10 percent gravel; Typical Pedon Location slightly acid; clear smooth boundary. Map unit in which located: Ragpie-Flatron Bt1—7 to 12 inches; brown (10YR 4/3) clay, very complex, 2 to 20 percent slopes dark grayish brown (10YR 3/2) moist; Location in survey area: About 7 miles east of moderate fine subangular blocky structure; 1 1 1 Hollister, Idaho; in the SE /4SW /4NE /4 of hard, firm, sticky and plastic; many very fine sec. 26, T. 12 S., R. 17 E. and fine roots; common very fine and fine tubular pores; common distinct clay films on Range in Characteristics faces of peds and in pores; 10 percent gravel; Profile: slightly acid; gradual wavy boundary. Depth to bedrock—10 to 20 inches Bt2—12 to 21 inches; dark brown (10YR 3/3) Jerome-Twin Falls, Idaho 181

gravelly clay, dark brown (10YR 3/3) moist; Chroma—2 or 3 strong coarse prismatic structure parting to Texture—clay or gravelly clay strong medium angular blocky; extremely Gravel content—10 to 30 percent hard, extremely firm, very sticky and very Bt3 horizon: plastic; common very fine and fine roots; few Hue—10YR or 7.5YR very fine and fine tubular pores; many Value—5 or 6 dry, 3 or 4 moist prominent clay films on faces of peds and in Chroma—3 or 4 pores; 15 percent gravel; slightly acid; abrupt Texture—very gravelly sandy clay or very smooth boundary. gravelly clay Bt3—21 to 30 inches; light brown (7.5YR 6/4) Gravel content—35 to 55 percent very gravelly sandy clay, brown (7.5YR 4/4) moist; moderate medium angular blocky Bkqm horizon: 1 structure; hard, firm, sticky and plastic; Thickness of upper silica lamination— /2 inch to common very fine and fine roots; few very 2 inches 1 fine and fine tubular pores; many distinct clay Thickness of lower silica laminations— /4 to 1 films on faces of peds and in pores; 35 inch percent gravel; slightly acid; abrupt smooth Thickness of duripan—4 to 11 inches boundary. Bkqm—30 to 35 inches; white (10YR 8/2) Gosinta Series indurated duripan, very pale brown (10YR 7/3) moist; massive; extremely hard, extremely Depth class: Very deep firm; few very fine and fine roots in fractures Drainage class: Moderately well drained of duripan; many continuous silica Permeability: Moderately slow laminations between cemented gravel; Position on landscape: Alluvial terraces 1 fractures /4 inch wide and 10 inches apart; Parent material: Kind—recent alluvium; source— violently effervescent; abrupt smooth mixed boundary. Slope range: 0 to 2 percent 2Cr—35 to 39 inches; very pale brown (10YR 7/4) Elevation: 3,000 to 5,000 feet welded volcanic ash, dark yellowish brown Average annual precipitation: 10 to 12 inches (10YR 4/6) moist; moderate medium platy Average annual air temperature: 47 to 50 structure; top of plates slightly effervescent. degrees F Frost-free period: 110 to 140 days Typical Pedon Location Taxonomic class: Fine-loamy, mixed, mesic Map unit in which located: Forvic silty clay loam, Cumulic Haploxerolls 2 to 6 percent slopes Location in survey area: About 19 miles Typical Pedon southeast of Rogerson, Idaho; in the 1 1 1 A1—0 to 2 inches; dark grayish brown (10YR 4/2) NE /4SE /4SE /4 of sec. 21, T. 16 S., R. 18 E. silt loam, very dark brown (10YR 2/2) moist; Range in Characteristics moderate medium platy structure; hard, friable, slightly sticky and slightly plastic; Profile: many roots; few very fine tubular pores; Depth to welded ash—24 to 50 inches neutral; abrupt smooth boundary. Depth to duripan—20 to 40 inches A2—2 to 8 inches; grayish brown (10YR 5/2) silt Thickness of mollic epipedon—20 to 30 loam, black (10YR 2/1) moist; moderate inches medium subangular blocky structure; slightly Particle-size control section: hard, friable, slightly sticky and slightly Clay content—50 to 59 percent plastic; many roots; many very fine tubular pores; mildly alkaline; gradual wavy boundary. A horizon: AB—8 to 24 inches; grayish brown (10YR 5/2) silt Value—3 or 4 dry loam, very dark brown (10YR 2/2) moist; Chroma—1 or 2 moderate medium subangular blocky Gravel content—5 to 25 percent structure; slightly hard, friable, slightly sticky Bt1 and Bt2 horizons: and slightly plastic; many roots; many very Value—3 to 5 dry, 2 or 3 moist fine tubular pores; strongly effervescent in 182 Soil Survey

places (5 percent calcium carbonate 2C2 horizon: equivalent); mildly alkaline; gradual wavy Value—5 or 6 dry, 3 or 4 moist boundary. Chroma—2 or 3 Bw—24 to 38 inches; light brownish gray (10YR Texture—very gravelly sandy loam or very 6/2) loam, dark brown (10YR 3/3) moist; gravelly loam common medium mottles that are strong Gravel content—35 to 55 percent brown (7.5YR 5/6) when moist; moderate medium subangular blocky structure; slightly Harsan Series hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; Depth class: Deep to a duripan many very fine tubular pores; neutral; clear Drainage class: Well drained smooth boundary. Permeability: Moderately slow C1—38 to 50 inches; pale brown (10YR 6/3) Position on landscape: Terraces sandy loam, very dark grayish brown (10YR Parent material: Kind—wind-modified alluvium; 3/2) moist; common medium to large mottles source—mixed that are strong brown (7.5YR 5/6) when Slope range: 1 to 8 percent moist; massive; slightly hard, friable, slightly Elevation: 3,500 to 4,000 feet sticky and slightly plastic; few very fine roots; Average annual precipitation: 9 to 10 inches few very fine tubular pores; 10 percent gravel; Average annual air temperature: 48 to 50 neutral; abrupt smooth boundary. degrees F 2C2—50 to 65 inches; grayish brown (10YR 5/2) Frost-free period: 130 to 140 days very gravelly sandy loam, very dark grayish Taxonomic class: Fine-loamy, mixed, mesic brown (10YR 3/2) moist; common medium to Xerollic Haplargids large mottles that are strong brown (7.5YR 5/6) when moist; massive; slightly hard, Typical Pedon friable; few very fine roots; few very fine A—0 to 4 inches; brown (10YR 5/3) loamy sand, irregular pores; 45 percent gravel; neutral. very dark grayish brown (10YR 3/2) moist; Typical Pedon Location single grain; loose; common very fine, fine, and medium roots; many very fine irregular Map unit in which located: Gosinta silt loam, 0 to pores; slightly acid; gradual wavy boundary. 2 percent slopes AB—4 to 9 inches; brown (10YR 5/3) loamy fine Location in survey area: About 3 miles south of 1 1 1 sand, dark brown (10YR 3/3) moist; weak Rock Creek, Idaho; in the NE /4SE /4SE /4 of medium subangular blocky structure; slightly sec. 11, T. 12 S., R. 18E. hard, very friable; few very fine, fine, and Range in Characteristics medium roots; many very fine irregular pores; neutral; clear smooth boundary. Profile: Bt1—9 to 19 inches; yellowish brown (10YR 5/4) Depth to bedrock—more than 60 inches sandy loam, brown (10YR 5/3) moist; Depth to mottles—24 to 60 inches moderate medium subangular blocky Depth to water table—24 to 48 inches structure; hard, friable, slightly sticky and Thickness of mollic epipedon—24 to 30 slightly plastic; few very fine, fine, and inches medium roots; many fine tubular pores; Particle-size control section: common faint clay films on faces of peds Clay content—20 to 30 percent and in pores and some clay bridges between sand grains; neutral; clear smooth A1 horizon: boundary. Value—3 to 5 dry, 2 or 3 moist Bt2—19 to 34 inches; light yellowish brown (10YR Chroma—2 or 3 6/4) sandy clay loam, yellowish brown (10YR Gravel content—0 to 10 percent 5/4) moist; strong medium subangular blocky Reaction—neutral or mildly alkaline structure; extremely hard, firm, slightly sticky Bw and C1 horizons: and slightly plastic; few very fine, fine, and Value—5 or 6 dry, 2 to 4 moist medium roots; common fine tubular pores; Chroma—2 to 4 common faint clay films on faces of peds Texture—loam, clay loam, or sandy loam and in pores and some clay bridges between Jerome-Twin Falls, Idaho 183

sand grains; mildly alkaline; gradual wavy Slope range: 3 to 40 percent boundary. Elevation: 6,800 to 7,600 feet 2Bkq—34 to 54 inches; very pale brown (10YR Average annual precipitation: 20 to 25 inches 7/3) clay loam, dark yellowish brown (10YR Average annual air temperature: 36 to 39 4/4) moist; moderate thin platy structure; very degrees F hard, firm, sticky and plastic; few very fine Frost-free period: 20 to 50 days and fine roots; few fine tubular pores; 5 Taxonomic class: Loamy-skeletal, mixed Argic percent gravel; strongly effervescent (18 Lithic Cryoborolls percent calcium carbonate equivalent); many soft lime masses; mildly alkaline; abrupt Typical Pedon wavy boundary. A—0 to 3 inches; brown (10YR 5/3) extremely 2Bkqm—54 to 60 inches; very pale brown (10YR gravelly loam, very dark grayish brown (10YR 8/3) duripan, light yellowish brown (10YR 6/4) 3/2) moist; moderate thick platy structure; moist; extremely hard, extremely firm. slightly hard, friable, slightly sticky and slightly plastic; many roots; many very fine Typical Pedon Location tubular pores; 70 percent gravel; strongly Map unit in which located: Harsan-Sidlake-Quincy acid; clear smooth boundary. complex, 1 to 8 percent slopes Bt1—3 to 9 inches; brown (10YR 4/3) very Location in survey area: About 6 miles northwest gravelly clay loam, very dark grayish brown 1 1 1 of Jerome, Idaho; in the SE /4SW /4SE /4 of (10YR 3/2) moist; moderate medium sec. 20, T. 7 S., R. 16 E. subangular blocky structure; slightly hard, friable, sticky and plastic; common roots; Range in Characteristics many very fine tubular pores; few faint clay Profile: films on faces of peds and in pores; 35 Depth to bedrock—more than 60 inches percent gravel; moderately acid; gradual wavy Depth to duripan—40 to 60 inches boundary. Bt2—9 to 15 inches; brown (10YR 4/3) very Particle-size control section: gravelly clay loam, dark brown (10YR 3/3) Clay content—18 to 30 percent moist; moderate fine angular blocky structure; A horizon: hard, firm, sticky and plastic; few roots; few Value—5 or 6 dry, 3 or 4 moist very fine tubular pores; common distinct clay Chroma—2 to 4 films on faces of peds and in pores; 40 Reaction—slightly acid or neutral percent gravel; strongly acid; abrupt wavy boundary. Bt horizon: R—15 inches; brown (10YR 4/3) welded tuff, dark Value—5 to 7 dry, 4 to 6 moist yellowish brown (10YR 3/4) moist. Chroma—3 or 4 Texture—sandy loam or sandy clay loam Typical Pedon Location Reaction—neutral or mildly alkaline Map unit in which located: Hogmalat-Rock 2Bkq horizon: outcrop complex, 3 to 40 percent slopes Value—6 to 8 dry, 4 to 6 moist Location in survey area: About 13 miles Chroma—2 to 4 southwest of Rogerson, Idaho; in the 1 1 1 Texture—clay loam, gravelly clay loam, or silt SE /4NE /4NE /4 of sec. 16, T. 15 S., R. 14 E. loam Range in Characteristics Gravel content—0 to 20 percent Profile: Hogmalat Series Depth to bedrock—9 to 20 inches Thickness of mollic epipedon—10 to 20 inches Depth class: Shallow to welded tuff Base saturation—50 to 55 percent Drainage class: Well drained Particle-size control section: Permeability: Moderately slow Clay content—24 to 34 percent Position on landscape: Shoulders and summits Parent material: Kind—residuum; source—welded A horizon: tuff Value—3 to 5 dry, 2 or 3 moist 184 Soil Survey

Chroma—1 to 3 BC2—50 to 62 inches; light yellowish brown Reaction—strongly acid or moderately acid (10YR 6/4) loam, dark yellowish brown (10YR 4/4) moist; massive; hard, firm, slightly sticky Bt horizon: and slightly plastic; slightly effervescent; Value—4 or 5 dry, 2 or 3 moist mildly alkaline; abrupt smooth boundary. Chroma—2 or 3 BC3—62 to 72 inches; yellowish brown (10YR Texture—very gravelly clay loam or very gravelly 5/4) loam, brown (10YR 4/3) moist; massive; loam slightly hard, very friable; strongly Gravel content—35 to 55 percent effervescent; mildly alkaline. Reaction—strongly acid or moderately acid Typical Pedon Location Hoosegow Series Map unit in which located: Hoosegow-Sidlake- Rock outcrop complex, 2 to 15 percent Depth class: Very deep slopes Drainage class: Well drained Location in survey area: About 12 miles Permeability: Moderate northeast of Jerome, Idaho; in the Position on landscape: Terraces 1 1 1 SE /4SE /4NE /4 of sec. 16, T. 7 S., R. 18 E. Parent material: Kind—alluvium; source—mixed Slope range: 2 to 15 percent Range in Characteristics Elevation: 3,500 to 4,000 feet Average annual precipitation: 9 to 11 inches Particle-size control section: Average annual air temperature: 47 to 49 Clay content—20 to 27 percent degrees F A horizon: Frost-free period: 130 to 140 days Value—4 or 5 dry, 3 or 4 moist Taxonomic class: Fine-loamy, mixed, mesic Chroma—3 or 4 Xerollic Haplargids Bt horizon: Typical Pedon Value—5 or 6 dry Chroma—3 or 4 A—0 to 6 inches; brown (10YR 5/3) loam, dark Texture—loam or sandy clay loam brown (10YR 3/3) moist; weak fine granular structure; soft, friable, slightly sticky and slightly plastic; many very fine and fine roots; Howcree Series many very fine and fine tubular pores; neutral; Depth class: Very deep clear smooth boundary. Drainage class: Well drained Bw—6 to 15 inches; yellowish brown (10YR 5/4) Permeability: Slow loam, brown (10YR 4/3) moist; moderate Position on landscape: Terraces medium subangular blocky structure; slightly Parent material: Kind—alluvium; source—welded hard, friable, slightly sticky and slightly tuff and volcanic ash plastic; common very fine and fine roots; Slope range: 2 to 6 percent many very fine and fine tubular pores; neutral; Elevation: 5,500 to 6,000 feet gradual wavy boundary. Average annual precipitation: 12 to 15 inches Bt—15 to 35 inches; yellowish brown (10YR 5/4) Average annual air temperature: 41 to 44 loam, brown (10YR 4/3) moist; moderate degrees F medium subangular blocky structure; very Frost-free period: 90 to 100 days hard, firm, sticky and plastic; few very fine and fine roots; many fine tubular pores; Taxonomic class: Clayey-skeletal, common distinct clay films on faces of peds montmorillonitic, frigid Ultic Argixerolls and in pores; neutral; gradual wavy boundary. Typical Pedon BC1—35 to 50 inches; light yellowish brown (10YR 6/4) loam, brown (10YR 4/3) moist; A—0 to 4 inches; dark grayish brown (10YR 4/2) moderate medium subangular blocky loam, very dark brown (10YR 2/2) moist; structure; hard, firm, sticky and plastic; few weak fine granular structure; slightly hard, very fine roots; many fine tubular pores; friable, slightly sticky and slightly plastic; mildly alkaline; gradual wavy boundary. many roots; many fine and very fine Jerome-Twin Falls, Idaho 185

tubular pores; slightly acid; clear smooth Bt1 and Bt2 horizons: boundary. Hue—10YR or 7.5YR Bt1—4 to 11 inches; grayish brown (10YR 5/2) Value—5 or 6 dry, 3 or 4 moist gravelly clay loam, very dark grayish brown Chroma—2 to 4 (10YR 3/2) moist; moderate medium Reaction—slightly acid or neutral subangular blocky structure; slightly hard, Texture—gravelly clay loam, gravelly clay, or very friable, sticky and plastic; common roots; gravelly clay many fine and very fine tubular pores; few Gravel content—25 to 50 percent faint clay films on faces of peds and in pores; Clay content—35 to 45 percent 30 percent gravel; slightly acid; gradual wavy Bt3 horizon: boundary. Hue—10YR or 7.5YR Bt2—11 to 19 inches; brown (10YR 5/3) gravelly Value—5 or 6 dry clay, dark brown (10YR 3/3) moist; strong fine Chroma—3 or 4 angular blocky structure; hard, firm, very Reaction—slightly acid or neutral sticky and very plastic; common roots; Texture—very gravelly clay or very gravelly common very fine and fine tubular pores; sandy clay common distinct clay films on faces of peds Gravel content—40 to 55 percent and in pores; 35 percent gravel; slightly acid; Cobble content—0 to 5 percent gradual wavy boundary. Clay content—45 to 55 percent Bt3—19 to 30 inches; pale brown (10YR 6/3) very gravelly clay, brown (10YR 4/3) moist; strong fine angular blocky structure; very hard, very Hutton Series firm, very sticky and very plastic; few very Depth class: Very deep fine roots; few very fine and fine tubular Drainage class: Poorly drained pores; common distinct clay films on faces of Permeability: Very slow peds and in pores; 55 percent gravel; neutral; Position on landscape: Flood plains gradual wavy boundary. Parent material: Kind—recent alluvium; source— Bq—30 to 60 inches; light yellowish brown welded tuff and volcanic ash (10YR 6/4) extremely gravelly sandy loam, Slope range: 0 to 2 percent dark yellowish brown (10YR 4/4) moist; Elevation: 5,500 to 5,800 feet strong fine angular blocky structure; very Average annual precipitation: 12 to 16 inches hard, firm, slightly sticky and slightly Average annual air temperature: 44 to 46 plastic; few very fine to medium roots; few degrees F very fine tubular pores; 80 percent gravel; Frost-free period: 50 to 90 days neutral. Taxonomic class: Fine, montmorillonitic, frigid Typical Pedon Location Cumulic Haplaquolls Map unit in which located: Howcree-Ibola Typical Pedon complex, 2 to 6 percent slopes 0e—0 to 2 inches; organic matter; decomposing Location in survey area: About 22 miles plant roots and leaves intermixed within southwest of Rogerson, Idaho; in the 1 1 1 grass sod. SW /4NE /4NW /4 of sec. 11, T. 15 S., A1—2 to 6 inches; very dark gray (N 3/0) silty R. 12 E. clay loam, black (N 2/0) moist; moderate Range in Characteristics medium granular structure; hard, firm, sticky and plastic; many very fine and fine roots; Profile: many fine tubular pores; neutral; clear smooth Depth to bedrock—more than 60 inches boundary. Thickness of mollic epipedon—12 to 20 inches A2—6 to 14 inches; very dark gray (N 3/0) silty Base saturation in upper 30 inches—60 to 70 clay loam, black (N 2/0) moist; moderate percent coarse prismatic structure; very hard, very A horizon: firm, very sticky and very plastic; common Value—4 or 5 dry, 2 or 3 moist very fine and fine roots; common fine tubular Chroma—1 to 3 pores; neutral; clear smooth boundary. 186 Soil Survey

BA—14 to 26 inches; gray (N 5/0) silty clay loam, Bg2 and Bg3 horizons: very dark gray (N 3/0) moist; weak medium Hue—10YR or 2.5Y prismatic structure; hard, firm, very sticky Value—5 to 7 dry, 2 to 5 moist and very plastic; common very fine and fine Chroma—1 or 2 roots; common very fine tubular pores; Texture—clay loam or clay slightly acid; abrupt smooth boundary. Clay content—30 to 50 percent Bg1—26 to 41 inches; gray (10YR 5/1) silty clay loam, very dark gray (10YR 3/1) moist; Ibola Series common medium prominent mottles that are light olive brown (2.5Y 5/6) when moist; Depth class: Moderately deep to a duripan strong coarse prismatic structure; very hard, Drainage class: Well drained very firm, very sticky and very plastic; few Permeability: Moderately slow very fine roots; common very fine tubular Position on landscape: Terraces pores; neutral; clear smooth boundary. Parent material: Kind—mixed alluvium; source— Bg2—41 to 50 inches; gray (10YR 5/1) clay, very welded tuff and volcanic ash dark gray (10YR 3/1) moist; many large Slope range: 2 to 6 percent prominent mottles that are olive brown (2.5Y Elevation: 5,500 to 6,000 feet 4/4) when moist; strong medium angular Average annual precipitation: 12 to 15 inches blocky structure; very hard, very firm, very Average annual air temperature: 41 to 46 sticky and very plastic; few very fine roots; degrees F few very fine tubular pores; neutral; gradual Frost-free period: 90 to 100 days wavy boundary. Taxonomic class: Fine-loamy, mixed, frigid Typic 2Bg3—50 to 62 inches; light gray (2.5Y 7/2) clay Durixerolls loam, grayish brown (2.5Y 5/2) moist; many medium prominent mottles that are light olive Typical Pedon brown (2.5Y 5/6) when moist; massive; hard, A—0 to 4 inches; brown (10YR 4/3) loam, very firm, sticky and plastic; few very fine roots; dark brown (10YR 2/2) moist; weak fine few very fine tubular pores; neutral. granular structure; soft, very friable, slightly Typical Pedon Location sticky and slightly plastic; many roots; many very fine and fine tubular pores; 5 percent Map unit in which located: Hutton mucky peat, 0 gravel; slightly acid; abrupt smooth boundary. to 2 percent slopes Bt1—4 to 8 inches; dark grayish brown (10YR Location in survey area: About 18 miles 4/2) loam, very dark brown (10YR 2/2) moist; southwest of Rogerson, Idaho; in the 1 1 1 moderate medium subangular blocky SW /4SW /4NW /4 of sec. 12, T. 15 S., structure; slightly hard, friable, slightly sticky R. 12 E. and slightly plastic; many roots; many very Range in Characteristics fine and fine tubular pores; few faint clay films on faces of peds and in pores; 5 Profile: percent gravel; moderately acid; clear smooth Depth to bedrock—more than 60 inches boundary. Depth to water table—12 to 24 inches Bt2—8 to 18 inches; grayish brown (10YR 5/2) Thickness of mollic epipedon—24 to 30 inches clay loam, dark brown (7.5YR 3/2) moist; Particle-size control section: strong medium angular blocky structure; Clay content—35 to 40 percent hard, firm, sticky and plastic; common roots; common very fine and fine tubular pores; A1 horizon: common distinct clay films on faces of peds Hue—10YR or neutral and in pores; moderately acid; clear smooth Value—3 to 5 dry, 2 or 3 moist boundary. Chroma—0 to 2 Bt3—18 to 27 inches; light brown (7.5YR 6/4) Bg1 horizon: gravelly loam, dark brown (7.5YR 4/4) moist; Hue—10YR or 2.5Y moderate medium subangular blocky Value—5 or 6 dry, 3 to 5 moist structure; hard, firm, slightly sticky and Chroma—1 or 2 slightly plastic; common roots; common very Texture—silty clay loam or clay loam fine and fine tubular pores; few faint clay Jerome-Twin Falls, Idaho 187

films on faces of peds and in pores; 15 Average annual air temperature: 47 to 49 percent gravel; moderately acid; abrupt degrees F smooth boundary. Frost-free period: 130 to 140 days Bqm—27 to 28 inches; white (10YR 8/2) duripan, Taxonomic class: Fine-loamy, mixed, mesic light gray (10YR 7/2) moist; continuous silica Xerollic Durargids cap over noncalcareous matrix; abrupt smooth boundary. Typical Pedon Crk—28 to 64 inches; light brown (7.5YR 6/4) Ap1—0 to 3 inches; yellowish brown (10YR 5/4) semiconsolidated volcanic ash, brown (7.5YR loam, dark brown (10YR 3/3) moist; weak fine 4/4) moist; noncalcareous matrix with lime granular structure; slightly hard, friable, masses intermixed. slightly sticky and slightly plastic; common very fine and fine roots and few medium Typical Pedon Location roots; common very fine and fine irregular Map unit in which located: Howcree-Ibola pores; neutral; gradual smooth boundary. complex, 2 to 6 percent slopes Ap2—3 to 7 inches; yellowish brown (10YR 5/4) Location in survey area: About 23 miles loam, dark brown (10YR 3/3) moist; moderate southwest of Rogerson, Idaho; in the fine granular structure; slightly hard, friable, 1 1 1 NW /4SW /4SW /4 of sec. 11, T. 15 S., slightly sticky and slightly plastic; common R. 12 E. very fine and fine roots and few medium roots; common very fine irregular pores and Range in Characteristics few fine irregular pores; neutral; clear smooth Profile: boundary. Depth to weathered bedrock—20 to 40 inches Bt1—7 to 12 inches; yellowish brown (10YR 5/4) Depth to duripan—20 to 40 inches loam, brown (10YR 4/3) moist; moderate Thickness of mollic epipedon—11 to 19 medium subangular blocky structure; slightly inches hard, friable, slightly sticky and slightly Thickness of duripan—1 inch to 4 inches plastic; common very fine and fine roots and few medium roots; common fine tubular A horizon: pores; common faint clay films on faces of Value—4 or 5 dry, 2 or 3 moist peds and in pores; neutral; gradual smooth Chroma—2 or 3 boundary. Gravel content—0 to 10 percent Bt2—12 to 23 inches; yellowish brown (10YR 5/4) Reaction—slightly acid or neutral loam, brown (10YR 4/3) moist; moderate Bt horizon: medium subangular blocky structure; slightly Hue—10YR or 7.5YR hard, firm, sticky and plastic; few very fine Value—4 to 6 dry, 2 to 4 moist roots; common fine tubular pores; common Chroma—2 to 4 faint clay films on faces of peds and in pores; Texture—loam, clay loam, gravelly loam, or neutral; gradual smooth boundary. gravelly clay loam Bk—23 to 39 inches; very pale brown (10YR 7/3) Clay content—24 to 34 percent silt loam, light yellowish brown (10YR 6/4) Gravel content—0 to 25 percent moist; moderate medium subangular blocky Cobble content—0 to 5 percent structure; slightly hard, firm, sticky and Reaction—moderately acid to neutral plastic; few very fine roots; few fine tubular pores; 5 percent gravel and 5 percent Idow Series cobbles; violently effervescent (35 percent calcium carbonate equivalent); moderately Depth class: Moderately deep to a duripan alkaline; abrupt smooth boundary. Drainage class: Well drained Bkqm—39 to 60 inches; very pale brown (10YR Permeability: Moderately slow 8/3) fractured duripan, very pale brown (10YR Position on landscape: Terraces 7/3) moist; platy; indurated; extremely hard, 1 Parent material: Kind—alluvium; source—mixed extremely firm; /4-inch-thick laminar silica Slope range: 1 to 4 percent lenses with gravelly sandy loam between Elevation: 3,500 to 4,000 feet plates; fractures more than 10 inches apart; Average annual precipitation: 9 to 10 inches violently effervescent. 188 Soil Survey

Typical Pedon Location 25 percent gravel; slightly acid; clear smooth boundary. Map unit in which located: Paulville-Idow Bt1—8 to 14 inches; dark grayish brown (10YR complex, 1 to 4 percent slopes 4/2) very gravelly clay loam, black (10YR Location in survey area: About 4 miles north of 1 1 1 2/1) moist; moderate medium subangular Jerome, Idaho; in the NE /4NE /4NE /4 of sec. blocky structure; hard, firm, sticky and 30, T. 7 S., R. 17 E. plastic; common roots; common very fine Range in Characteristics tubular pores; common distinct clay films on faces of peds and in pores; 40 percent gravel; Profile: neutral; gradual wavy boundary. Depth to secondary lime—17 to 33 inches Bt2—14 to 23 inches; dark grayish brown (10YR Depth to duripan—20 to 40 inches 4/2) very gravelly clay, black (10YR 2/1) Ap1 horizon: moist; strong fine angular blocky structure; Value—4 or 5 dry, 3 or 4 moist very hard, very firm, very sticky and very Chroma—3 or 4 plastic; few very fine roots; few very fine tubular pores; many prominent clay films on Bt horizon: faces of peds and in pores; 50 percent gravel; Value—5 or 6 dry, 3 or 4 moist slightly acid; abrupt smooth boundary. Chroma—3 or 4 Bt3—23 to 38 inches; pale brown (10YR 6/3) Texture—loam or clay loam extremely gravelly clay, brown (10YR 4/3) Clay content—20 to 30 percent moist; moderate fine angular blocky structure; Bk horizon: very hard, very firm, very sticky and very Value—6 or 7 dry, 4 to 6 moist plastic; few very fine tubular pores; many Chroma—3 or 4 prominent clay films on faces of peds and in Texture—silt loam, clay loam, or loam pores; 70 percent gravel; slightly acid; abrupt Gravel content—0 to 5 percent smooth boundary. Cobble content—0 to 5 percent 2C—38 to 60 inches; pale brown (10YR 6/3) Durinode content—0 to 10 percent extremely gravelly sandy loam, brown (10YR Effervescence—slight to violent 4/3) moist; massive; extremely hard, very firm; few very fine tubular pores; 70 percent Isknat Series gravel; neutral. Typical Pedon Location Depth class: Very deep Drainage class: Well drained Map unit in which located: Isknat gravelly loam, Permeability: Slow 3 to 15 percent slopes Position on landscape: Fan terraces and alluvial Location in survey area: About 13 miles fans southwest of Rogerson, Idaho; in the 1 1 1 Parent material: Kind—colluvium; source—mixed NW /4NW /4NW /4 of sec. 26, T. 15 S., Slope range: 2 to 15 percent R. 14 E. Elevation: 5,200 to 5,900 feet Range in Characteristics Average annual precipitation: 12 to 16 inches Average annual air temperature: 42 to 44 Profile: degrees F Depth to bedrock—more than 60 inches Frost-free period: 80 to 90 days Thickness of mollic epipedon—20 to 34 inches Base saturation—65 to 75 percent Taxonomic class: Clayey-skeletal, montmorillonitic, frigid Pachic Ultic Particle-size control section: Argixerolls Clay content—35 to 50 percent Typical Pedon A horizon: Value—3 to 5 dry, 2 or 3 moist A—0 to 8 inches; gray (10YR 5/1) gravelly loam, Chroma—1 to 3 very dark gray (10YR 3/1) moist; moderate medium platy structure; slightly hard, friable, Bt1 horizon: slightly sticky and slightly plastic; many Value—4 or 5 dry, 2 or 3 moist roots; many very fine and fine tubular pores; Chroma—1 or 2 Jerome-Twin Falls, Idaho 189

Texture—very gravelly clay loam or gravelly clay tubular pores; common distinct clay films on loam faces of peds and in pores; slightly acid; Gravel content—30 to 50 percent clear wavy boundary. Bt2—12 to 21 inches; brown (10YR 5/3) clay, Bt2 and Bt3 horizons: dark brown (10YR 3/3) moist; moderate Hue—10YR or 7.5YR medium prismatic structure; very hard, very Value—4 to 6 dry, 2 to 4 moist firm, very sticky and very plastic; common Chroma—1 to 4 roots; common very fine tubular pores; many Texture—very gravelly clay or extremely gravelly distinct clay films on faces of peds and in clay pores; 5 percent gravel and 5 percent Gravel content—40 to 70 percent cobbles; neutral; gradual wavy boundary. Cobble content—0 to 5 percent Bt3—21 to 30 inches; pale brown (10YR 6/3) clay, Reaction—slightly acid or neutral brown (10YR 4/3) moist; strong medium 2Bt horizon (where present): angular blocky structure; very hard, very firm, Texture—clayey below a depth of 40 inches very sticky and very plastic; common roots; common very fine tubular pores; common 2C horizon (where present): distinct clay films on faces of peds and in Value—5 to 8 dry, 4 to 6 moist pores; 5 percent gravel and 5 percent Chroma—3 to 6 cobbles; neutral; clear wavy boundary. Texture—extremely gravelly sandy loam or Bk—30 to 42 inches; very pale brown (10YR 7/3) extremely gravelly loamy sand (sandy- gravelly loam, brown (10YR 5/3) moist; skeletal below a depth of 40 inches only) massive; hard, firm, slightly sticky and Gravel content—60 to 70 percent slightly plastic; few roots; few very fine Cobble content—10 to 20 percent tubular pores; 20 percent gravel; strongly effervescent (35 percent calcium carbonate Iwica Series equivalent); mildly alkaline; abrupt smooth boundary. Depth class: Deep to a duripan 2Bkqm—42 to 60 inches; white (10YR 8/1) Drainage class: Well drained duripan, light gray (10YR 7/2) moist; Permeability: Slow indurated; extremely hard, extremely firm; Position on landscape: Terraces 1 /8-inch-thick laminar cap over strongly Parent material: Kind—alluvium; source—mixed cemented sand and gravel. Slope range: 2 to 6 percent Elevation: 5,500 to 6,000 feet Typical Pedon Location Average annual precipitation: 12 to 15 inches Average annual air temperature: 42 to 44 Map unit in which located: Iwica-Budlewis degrees F complex, 2 to 6 percent slopes Frost-free period: 90 to 100 days Location in survey area: About 36 miles southwest of Twin Falls, Idaho; in the Taxonomic class: Fine, montmorillonitic, frigid 1 1 1 NW /4SE /4SW /4 of sec. 29, T. 14 S., R. 13 E. Calcic Pachic Argixerolls Range in Characteristics Typical Pedon Profile: A—0 to 5 inches; dark grayish brown (10YR 4/2) Depth to bedrock—more than 60 inches silt loam, black (10YR 2/1) moist; moderate Depth to duripan—40 to 60 inches medium platy structure; slightly hard, friable, Thickness of mollic epipedon—20 to 26 slightly sticky and slightly plastic; many very inches fine and fine roots; many very fine tubular Base saturation—65 to 75 percent pores; 5 percent gravel; slightly acid; clear A horizon: smooth boundary. Value—4 or 5 dry, 2 or 3 moist Bt1—5 to 12 inches; grayish brown (10YR 5/2) Chroma—1 or 2 silty clay loam, very dark grayish brown (10YR 3/2) moist; strong fine angular blocky Bt horizon: structure; hard, friable, sticky and plastic; Value—4 to 6 dry, 2 to 4 moist many very fine and fine roots; many very fine Chroma—2 or 3 190 Soil Survey

Texture—silty clay loam or clay massive; hard, firm, sticky and slightly Gravel content—0 to 5 percent plastic; few very fine roots; common very Cobble content—0 to 5 percent fine and fine tubular pores; 5 percent gravel Clay content—30 to 55 percent and 10 percent cobbles; violently effervescent (20 percent calcium carbonate Bk horizon: equivalent); moderately alkaline; abrupt Value—6 or 7 dry, 4 or 5 moist smooth boundary. Chroma—3 or 4 2Bkqm—35 to 39 inches; white (10YR 8/2) Texture—gravelly loam or gravelly clay loam indurated duripan, gray (10YR 6/2) moist; Gravel content—20 to 30 percent 1 many continuous /8-inch-thick laminar caps; Clay content—20 to 35 percent abrupt wavy boundary. Bkqm horizon: 3R—39 inches; fractured basalt; lime coating on 1 Thickness of upper silica lamination— /8 to 1 inch surface and in fractures. Thickness of duripan—20 inches or more Typical Pedon Location Jestrick Series Map unit in which located: Jestrick-Kecko complex, 1 to 8 percent slopes Depth class: Moderately deep to a duripan Location in survey area: About 6 miles Drainage class: Somewhat excessively drained southwest of Jerome, Idaho; in the Permeability: Moderately rapid 1 1 1 NW /4NE /4SW /4 of sec. 4, T. 9 S., R. 16 E. Position on landscape: Terraces Parent material: Kind—eolian material; source— Range in Characteristics mixed Slope range: 1 to 8 percent Profile: Elevation: 3,500 to 4,000 feet Depth to bedrock—25 to 40 inches Average annual precipitation: 9 to 10 inches Depth to duripan—21 to 38 inches Average annual air temperature: 47 to 49 Ap horizon: degrees F Value—5 or 6 dry, 3 or 4 moist Frost-free period: 130 to 140 days Chroma—2 or 3 Taxonomic class: Coarse-loamy, mixed, mesic Bw horizon: Xerollic Durorthids Value—5 or 6 dry, 3 or 4 moist Typical Pedon Chroma—3 or 4 Texture—fine sandy loam or sandy loam Ap—0 to 12 inches; brown (10YR 5/3) loamy fine Gravel content—0 to 5 percent sand, dark brown (10YR 3/3) moist; single grain; loose; many very fine and fine roots; 2Bkq horizon: many very fine and fine interstitial pores; 2 Value—5 or 6 dry, 3 or 4 moist percent gravel; neutral; abrupt smooth Chroma—3 or 4 boundary. Gravel content—5 to 10 percent Bw1—12 to 22 inches; yellowish brown (10YR Cobble content—10 to 15 percent 5/4) fine sandy loam, brown (10YR 4/3) Calcium carbonate equivalent—10 to 20 moist; weak fine granular structure; loose; percent common very fine and fine roots; many very Effervescence—strong or violent fine and fine tubular pores; 2 percent gravel; mildly alkaline; clear wavy boundary. Kavon Series Bw2—22 to 31 inches; yellowish brown (10YR 5/4) fine sandy loam, brown (10YR 4/3) Depth class: Very deep moist; moderate medium subangular blocky Drainage class: Well drained structure; hard, friable; few very fine roots; Permeability: Moderately slow many very fine and fine tubular pores; 2 Position on landscape: Hill slopes percent gravel; mildly alkaline; abrupt smooth Parent material: Kind—glacial till and colluvium; boundary. source—welded tuff and volcanic ash 2Bkq—31 to 35 inches; pale brown (10YR 6/3) Slope range: 5 to 35 percent cobbly loam, brown (10YR 5/3) moist; Elevation: 6,800 to 7,700 feet Jerome-Twin Falls, Idaho 191

Average annual precipitation: 20 to 25 inches Location in survey area: About 23 miles Average annual air temperature: 38 to 41 southwest of Rogerson, Idaho; in the 1 1 1 degrees F SW /4SW /4NW /4 of sec. 21, T. 16 S., Frost-free period: 20 to 50 days R. 13 E. Taxonomic class: Loamy-skeletal, mixed, frigid Range in Characteristics Xeric Palehumults Profile: Depth to bedrock—more than 60 inches Typical Pedon Thickness of umbric epipedon—30 to 50 A1—0 to 4 inches; brown (10YR 4/3) very inches gravelly loam, very dark brown (10YR 2/2) Rock fragment content—40 to 80 percent moist; weak fine granular structure; slightly Base saturation—less than 15 percent hard, friable, slightly sticky and slightly Particle-size control section: plastic; common very fine and fine roots; Clay content—20 to 30 percent many very fine tubular pores; 60 percent gravel and 3 percent boulders; extremely A1 and A2 horizons: acid; clear smooth boundary. Chroma—1 to 3 A2—4 to 12 inches; dark grayish brown (10YR Reaction—very strongly acid or extremely 4/2) very gravelly loam, very dark brown acid (10YR 2/2) moist; weak medium subangular Bt1 and Bt2 horizons: blocky structure; slightly hard, friable, slightly Value—4 to 6 dry, 3 or 4 moist sticky and slightly plastic; common very fine Chroma—2 to 4 and fine roots; many very fine tubular pores; Texture—very gravelly loam or extremely 50 percent gravel; extremely acid; gradual gravelly clay loam wavy boundary. Gravel content—40 to 70 percent Bt1—12 to 20 inches; brown (10YR 5/3) very Cobble content—0 to 10 percent gravelly loam, dark brown (10YR 3/3) moist; Base saturation—5 to 20 percent moderate medium subangular blocky structure; hard, firm, slightly sticky and Bt3 horizon: slightly plastic; few very fine roots; common Hue—10YR or 7.5YR very fine tubular pores; few faint clay films on Chroma—3 or 4 faces of peds and in pores; 50 percent gravel; Texture—extremely cobbly clay, extremely extremely acid; clear smooth boundary. gravelly clay loam, or extremely cobbly Bt2—20 to 39 inches; brown (10YR 4/3) very clay loam gravelly loam, dark brown (10YR 3/3) moist; Gravel content—35 to 40 percent moderate medium subangular blocky Cobble content—20 to 40 percent structure; hard, firm, slightly sticky and Stone content—5 to 10 percent slightly plastic; few very fine tubular pores; few faint clay films on faces of peds and in Kecko Series pores; 50 percent gravel; extremely acid; clear smooth boundary. Depth class: Very deep Bt3—39 to 62 inches; light yellowish brown (10YR Drainage class: Well drained 6/4) extremely gravelly clay loam, dark Permeability: Moderately rapid yellowish brown (10YR 4/4) moist; strong fine Position on landscape: Terraces angular blocky structure; hard, firm, sticky Parent material: Kind—wind-modified alluvium; and plastic; few very fine tubular pores; source—mixed common distinct clay films on faces of peds Slope range: 1 to 8 percent and in pores; 40 percent gravel, 20 percent Elevation: 2,900 to 4,400 feet cobbles, and 5 percent stones; extremely Average annual precipitation: 8 to 11 inches acid. Average annual air temperature: 48 to 51 degrees F Typical Pedon Location Frost-free period: 120 to 140 days Map unit in which located: Kavon very gravelly Taxonomic class: Coarse-loamy, mixed, mesic loam, 5 to 35 percent slopes Xerollic Camborthids 192 Soil Survey

Typical Pedon Chroma—2 to 4 Texture—fine sandy loam, sandy loam, or loamy A—0 to 7 inches; brown (10YR 5/3) loamy fine fine sand sand, dark brown (10YR 3/3) moist; single grain; loose; many roots; many very fine to Bk horizon: fine irregular pores; 2 percent gravel; neutral; Value—4 to 6 moist clear smooth boundary. Chroma—2 or 3 Bw—7 to 25 inches; yellowish brown (10YR 5/4) Texture—fine sandy loam, loamy fine sand, fine sandy loam, brown (10YR 4/3) moist; loamy sand, or sandy loam weak medium subangular blocky structure; Calcium carbonate equivalent—15 to 25 percent loose; many roots; many very fine and fine irregular pores; 5 percent gravel; neutral; Keman Series abrupt smooth boundary. Bk1—25 to 38 inches; very pale brown (10YR Depth class: Very deep 7/3) fine sandy loam, brown (10YR 5/3) Drainage class: Well drained moist; massive; hard, firm; common very fine Permeability: Moderate and fine roots; common very fine tubular Position on landscape: Summits pores; strongly effervescent (15 percent Parent material: Kind—glacial till and colluvium; calcium carbonate equivalent); moderately source—welded tuff and volcanic ash alkaline; abrupt smooth boundary. Slope range: 2 to 35 percent Bk2—38 to 48 inches; very pale brown (10YR Elevation: 6,800 to 7,700 feet 7/3) sandy loam, brown (10YR 5/3) moist; Average annual precipitation: 20 to 25 inches moderate medium platy structure; extremely Average annual air temperature: 38 to 41 hard, very firm; common very fine and fine degrees F roots; few very fine tubular pores; violently Frost-free period: 20 to 50 days effervescent (21 percent calcium carbonate Taxonomic class: Loamy-skeletal, mixed Argic equivalent); moderately alkaline; abrupt Pachic Cryoborolls smooth boundary. 2Bk—48 to 74 inches; pale brown (10YR 6/3) fine Typical Pedon sand, grayish brown (10YR 5/2) moist; A—0 to 5 inches; very dark gray (10YR 3/1) very massive; soft, very friable; few very fine gravelly loam, black (10YR 2/1) moist; weak tubular pores; strongly effervescent (20 fine granular structure; soft, very friable, percent calcium carbonate equivalent); slightly sticky and slightly plastic; many very moderately alkaline. fine and fine roots; many very fine tubular Typical Pedon Location pores; 50 percent gravel; moderately acid; gradual wavy boundary. Map unit in which located: Kecko-Emberton AB—5 to 14 inches; very dark grayish brown complex, 1 to 6 percent slopes (10YR 3/2) very gravelly loam, black (10YR Location in survey area: About 6 miles northwest 1 1 1 2/1) moist; moderate medium subangular of Eden, Idaho; in the NW /4SE /4SW /4 of blocky structure; slightly hard, friable, slightly sec. 21, T. 9 S., R. 17 E. sticky and slightly plastic; many very fine Range in Characteristics and fine roots; many very fine tubular pores; 50 percent gravel; moderately acid; gradual Profile: wavy boundary. Depth to bedrock—more than 60 inches Bt1—14 to 33 inches; dark grayish brown (10YR Depth to secondary lime—20 to 30 inches 4/2) very gravelly loam, very dark brown Particle-size control section: (10YR 2/2) moist; moderate medium Clay content—10 to 18 percent subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; A horizon: common very fine and fine roots; common Value—5 or 6 dry, 2 to 4 moist very fine tubular pores; common faint clay Chroma—2 or 3 films on faces of peds and in pores; 55 Bw horizon: percent gravel; moderately acid; abrupt Value—5 or 6 dry, 3 or 4 moist smooth boundary. Jerome-Twin Falls, Idaho 193

Bt2—33 to 60 inches; light brownish gray (10YR Position on landscape: Terraces and breaks 6/2) extremely gravelly clay loam, dark Parent material: Kind—lacustrine sediment; grayish brown (10YR 4/2) moist; moderate source—mixed medium subangular blocky structure; hard, Slope range: 4 to 60 percent firm, sticky and plastic; few fine roots; few Elevation: 2,800 to 3,500 feet very fine tubular pores; few faint clay films on Average annual precipitation: 8 to 10 inches faces of peds and in pores; 65 percent gravel; Average annual air temperature: 49 to 51 moderately acid. degrees F Frost-free period: 130 to 140 days Typical Pedon Location Taxonomic class: Fine-silty, mixed (calcareous), Map unit in which located: Keman very gravelly mesic Xeric Torriorthents loam, 2 to 35 percent slopes Location in survey area: About 26 miles Typical Pedon southwest of Rogerson, Idaho; in the 1 1 1 NW /4NE /4SE /4 of sec. 26, T. 16 S., R. 12 E. A1—0 to 4 inches; light gray (10YR 7/2) silty clay, yellowish brown (10YR 5/4) moist; Range in Characteristics moderate very fine granular structure; slightly Profile: hard, friable, very sticky and very plastic; Depth to bedrock—more than 60 inches common fine roots; common fine vesicular Thickness of mollic epipedon—30 to 50 inches pores; slightly effervescent (6 percent Rock fragment content—40 to 75 percent calcium carbonate equivalent); moderately Base saturation—50 to 70 percent alkaline; abrupt smooth boundary. A2—4 to 7 inches; light gray (10YR 7/2) clay, Particle-size control section: pale brown (10YR 6/3) moist; weak thin platy Clay content—18 to 24 percent structure; slightly hard, friable, very sticky A horizon: and very plastic; common very fine, fine, and Value—3 or 4 dry medium roots; common very fine tubular Chroma—1 to 3 pores; slightly effervescent (6 percent Reaction—strongly acid or moderately acid calcium carbonate equivalent); few fine segregated lime filaments; moderately Bt1 horizon: alkaline; abrupt smooth boundary. Value—3 to 5 dry, 2 or 3 moist 2Bk1—7 to 11 inches; pale brown (10YR 6/3) Chroma—1 to 3 loam, brown (10YR 5/3) moist; massive; hard, Texture—very gravelly loam or extremely gravelly firm, slightly sticky and slightly plastic; few loam very fine, fine, and medium roots; few very Clay content—14 to 24 percent fine and fine tubular pores; strongly Gravel content—40 to 70 percent effervescent (8 percent calcium carbonate Cobble content—0 to 10 percent equivalent); many fine segregated lime Bt2 horizon: filaments; moderately alkaline; abrupt smooth Value—5 or 6 dry boundary. Chroma—2 to 4 2Bk2—11 to 14 inches; brown (10YR 5/3) sandy Texture—very gravelly loam or extremely gravelly loam, dark brown (10YR 4/3) moist; massive; clay loam hard, very firm, slightly sticky and slightly Clay content—24 to 34 percent plastic; few very fine, fine, and medium roots; Gravel content—40 to 65 percent few very fine tubular pores; slightly Cobble content—0 to 15 percent effervescent (5 percent calcium carbonate Stone content—0 to 5 percent equivalent); lime in soft segregated masses; Reaction—strongly acid or moderately acid moderately alkaline; abrupt smooth boundary. 3Bk3—14 to 27 inches; brown (10YR 5/3) silty Kudlac Series clay loam, dark grayish brown (10YR 4/2) moist; massive; very hard, very firm, sticky Depth class: Very deep and plastic; few very fine, fine, and medium Drainage class: Well drained roots; few very fine and fine tubular pores; Permeability: Very slow strongly effervescent (10 percent calcium 194 Soil Survey

carbonate equivalent); many soft segregated Lankbush Series lime masses; moderately alkaline; abrupt smooth boundary. Depth class: Very deep 3C1—27 to 30 inches; white (10YR 8/2) silty clay Drainage class: Well drained loam, pale brown (10YR 6/3) moist; massive; Permeability: Moderately slow very hard, extremely firm, sticky and plastic; Position on landscape: Foot slopes and terraces few very fine and fine roots; few very fine Parent material: Kind—alluvium; source—welded and fine tubular pores; violently effervescent tuff and volcanic ash (38 percent calcium carbonate equivalent); Slope range: 2 to 10 percent strongly alkaline; abrupt smooth Elevation: 3,000 to 5,500 feet boundary. Average annual precipitation: 9 to 12 inches 3C2—30 to 43 inches; brown (7.5YR 5/2) silty Average annual air temperature: 46 to 48 clay loam, dark brown (7.5YR 4/2) moist; degrees F massive; very hard, very firm, sticky and Frost-free period: 100 to 140 days plastic; few very fine and fine roots; few very Taxonomic class: Fine-loamy, mixed, mesic fine and fine tubular pores; strongly Xerollic Haplargids effervescent (9 percent calcium carbonate equivalent); strongly alkaline; clear smooth Typical Pedon boundary. A—0 to 6 inches; brown (10YR 5/3) loamy sand, 4C3—43 to 60 inches; grayish brown (2.5Y 5/2) dark brown (10YR 4/3) moist; single grain; silty clay, grayish brown (2.5Y 5/2) moist; loose; many very fine and fine roots; many massive; hard, very firm, very sticky and very fine discontinuous irregular pores; 5 very plastic; few very fine and fine roots; few percent gravel; neutral; abrupt smooth very fine and fine tubular pores; few lime boundary. veins in noncalcareous matrix; moderately Bt—6 to 20 inches, brown (10YR 5/3) sandy alkaline. clay loam, dark brown (10YR 4/3) moist; Typical Pedon Location moderate medium subangular blocky structure; hard, firm, slightly sticky and Map unit in which located: Kudlac silty clay, 4 to slightly plastic; common very fine roots; 30 percent slopes many fine and very fine discontinuous tubular Location in survey area: About 14 miles pores; common faint clay films on faces of northwest of Buhl, Idaho; in the 1 1 1 peds and in pores; mildly alkaline; clear NE /4NE /4SE /4 of sec. 18, T. 8 S., R. 13 E. smooth boundary. Range in Characteristics Bw1—20 to 38 inches; light yellowish brown (10YR 6/4) sandy loam, brown (10YR 5/3) Profile: moist; weak medium subangular blocky Depth to hard lacustrine sediment—4 to 20 structure; hard, firm; common very fine roots; inches common very fine and fine discontinuous Depth to bedrock—more than 60 inches tubular pores; 5 percent gravel; mildly Calcium carbonate equivalent—5 to 40 percent alkaline; clear smooth boundary. Reaction—moderately alkaline or strongly Bw2—38 to 46 inches; light yellowish brown alkaline (10YR 6/4) loamy sand, yellowish brown Particle-size control section: (10YR 5/4) moist; massive; hard, firm; Clay content—25 to 34 percent common very fine roots; few very fine and fine discontinuous tubular pores; 10 percent A1 horizon: gravel; slightly effervescent; mildly alkaline; Value—6 or 7 dry, 4 to 6 moist clear smooth boundary. Chroma—2 to 4 2Bk1—46 to 60 inches; very pale brown (10YR 2Bk, 3Bk, and 3C horizons: 7/3) loamy sand, light yellowish brown (10YR Hue—10YR, 7.5YR, or 2.5Y 6/4) moist; massive; loose; common very fine Value—5 to 8 dry, 4 to 6 moist roots; few very fine and fine discontinuous Chroma—2 to 4 tubular pores; 5 percent gravel; strongly Texture—loam, sandy loam, silt loam, silty clay effervescent; moderately alkaline; clear loam, or silty clay smooth boundary. Jerome-Twin Falls, Idaho 195

2Bk2—60 to 65 inches; very pale brown (10YR Typical Pedon 7/4) sandy loam, light yellowish brown (10YR A—0 to 2 inches; pale brown (10YR 6/3) silt 6/4) moist; massive; very hard, firm, slightly loam, dark brown (10YR 3/3) moist; moderate sticky and slightly plastic; few fine roots; few medium platy structure; slightly hard, friable, fine and very fine discontinuous tubular slightly sticky and slightly plastic; common pores; 10 percent gravel; strongly very fine and fine roots; many very fine effervescent; moderately alkaline. tubular pores; 5 percent gravel and Typical Pedon Location 5 percent cobbles; neutral; clear smooth boundary. Map unit in which located: Lankbush loamy sand, Bt1—2 to 8 inches; pale brown (10YR 6/3) silty 2 to 10 percent slopes clay loam, brown (10YR 4/3) moist; weak fine Location in survey area: About 13 miles angular blocky structure; hard, firm, sticky southwest of Rogerson, Idaho; in the 1 1 1 and plastic; common very fine and fine roots; NE /4NW /4NW /4 of sec. 5, T. 16 S., R. 15 E. many very fine tubular pores; few faint clay films on faces of peds and in pores; neutral; Range in Characteristics clear smooth boundary. Profile: Bt2—8 to 11 inches; pale brown (10YR 6/3) Depth to bedrock—more than 60 inches silty clay loam, brown (10YR 4/3) moist; Depth to secondary lime—more than 40 inches strong medium angular blocky structure; hard, firm, sticky and plastic; common A horizon: very fine roots; common very fine tubular Value—5 or 6 dry, 3 or 4 moist pores; many distinct clay films on Chroma—3 or 4 faces of peds and in pores; strongly Gravel content—0 to 10 percent effervescent (4 percent calcium carbonate Bt horizon: equivalent); mildly alkaline; clear smooth Value—5 or 6 dry, 3 or 4 moist boundary. Chroma—3 or 4 Bkq—11 to 16 inches; very pale brown (10YR Gravel content—0 to 10 percent 7/3) gravelly loam, brown (10YR 4/3) moist; Clay content—20 to 29 percent moderate medium subangular blocky structure; very hard, very firm, slightly sticky 2Bk horizon: and slightly plastic; few very fine roots; few Value—6 or 7 dry, 5 or 6 moist very fine tubular pores; 20 percent gravel; Chroma—3 or 4 violently effervescent (32 percent calcium Texture—loamy sand, gravelly loamy sand, or carbonate equivalent); mildly alkaline; abrupt sandy loam smooth boundary. Gravel content—0 to 25 percent Bkqm—16 to 26 inches; white (10YR 8/1) Reaction—mildly alkaline or moderately fractured duripan, very pale brown (10YR 7/3) alkaline moist; massive; indurated; extremely hard, 1 extremely firm; many /8- to 1-inch-thick lime- Lud Series and silica-cemented lenses; few very fine 1 roots in fractures of duripan; fractures /4 inch Depth class: Shallow to a duripan wide and 9 inches apart; violently Drainage class: Well drained effervescent; moderately alkaline; abrupt Permeability: Slow wavy boundary. Position on landscape: Terraces 2R—26 inches; dark gray (10YR 4/1) fractured Parent material: Kind—alluvium; source—mixed basalt, black (10YR 2/1) moist; lime coating; Slope range: 2 to 10 percent violently effervescent. Elevation: 4,500 to 5,300 feet Average annual precipitation: 9 to 11 inches Typical Pedon Location Average annual air temperature: 45 to 47 Map unit in which located: Lud silt loam, 2 to 10 degrees F percent slopes Frost-free period: 100 to 120 days Location in survey area: About 13 miles west of 1 1 1 Taxonomic class: Clayey, montmorillonitic, Rogerson, Idaho; in the NE /4NE /4NW /4 of mesic, shallow Xerollic Durargids sec. 17, T. 14 S., R. 14 E. 196 Soil Survey

Range in Characteristics slightly hard, friable, sticky and plastic; common very fine and fine roots; many very Profile: fine tubular pores; 30 percent gravel and 5 Depth to bedrock—21 to 40 inches percent cobbles; mildly alkaline; abrupt Depth to duripan—10 to 20 inches smooth boundary. Particle-size control section: Bk1—10 to 16 inches; very pale brown (10YR Clay content—35 to 45 percent 7/3) extremely cobbly loam, brown (10YR 5/3) moist; massive; slightly hard, friable, A horizon: slightly sticky and slightly plastic; few very Value—5 or 6 dry, 3 or 4 moist fine and fine roots; common very fine Chroma—2 or 3 irregular pores; 35 percent gravel and 45 Bt horizon: percent cobbles; strongly effervescent (17 Value—6 or 7 dry, 4 or 5 moist percent calcium carbonate equivalent); Chroma—3 or 4 moderately alkaline; abrupt smooth Texture—silty clay loam, silty clay, cobbly silty boundary. clay, or cobbly silty clay loam Bk2—16 to 36 inches; very pale brown (10YR Reaction—neutral or mildly alkaline 7/3) extremely gravelly sandy loam, brown (10YR 5/3) moist; massive; hard, firm, Bkqm horizon: 1 slightly sticky and slightly plastic; few very Thickness of upper silica lamination— /8 inch to 1 fine roots; common very fine irregular pores; 1 /2 inches 1 50 percent gravel and 20 percent cobbles; Thickness of lower silica laminations— /8 to 1 strongly effervescent (23 percent calcium inch carbonate equivalent); moderately alkaline; Cementation between laminations—weak to very gradual wavy boundary. strong R—36 inches; extremely hard welded tuff. Thickness of duripan—3 to 20 inches Typical Pedon Location Mackey Series Map unit in which located: Mackey very gravelly loam, 8 to 30 percent slopes Depth class: Moderately deep to welded tuff Location in survey area: About 8 miles northeast Drainage class: Well drained 1 1 1 of Hollister, Idaho; in the SE /4NE /4NW /4 of Permeability: Moderate sec. 14, T. 12 S., R. 17 E. Position on landscape: Dip slopes Parent material: Kind—residuum and colluvium; Range in Characteristics source—mixed Profile: Slope range: 8 to 30 percent Depth to bedrock—20 to 40 inches Elevation: 4,300 to 5,500 feet Depth to secondary lime—8 to 20 inches Average annual precipitation: 10 to 13 inches Average annual air temperature: 47 to 49 A horizon: degrees F Value—5 to 7 dry, 3 or 4 moist Frost-free period: 100 to 120 days Chroma—2 or 3 Gravel content—30 to 45 percent Taxonomic class: Loamy-skeletal, mixed, mesic Cobble content—0 to 10 percent Xerollic Camborthids Bw horizon: Typical Pedon Value—6 or 7 dry, 3 or 4 moist Chroma—3 or 4 A—0 to 3 inches; pale brown (10YR 6/3) very Texture—very gravelly clay loam or very gravelly gravelly loam, dark brown (10YR 3/3) moist; loam weak fine platy structure; slightly hard, Gravel content—30 to 40 percent friable, slightly sticky and slightly plastic; Cobble content—5 to 15 percent many roots; many very fine tubular pores; 40 percent gravel; neutral; clear wavy boundary. Bk horizon: Bw—3 to 10 inches; pale brown (10YR 6/3) very Value—6 or 7 dry, 4 or 5 moist gravelly clay loam, brown (10YR 4/3) moist; Chroma—2 to 4 weak medium subangular blocky structure; Texture—extremely gravelly sandy loam, Jerome-Twin Falls, Idaho 197

1 1 1 extremely gravelly loam, or very gravelly of Jerome, Idaho; in the NE /4NE /4NE /4 of sandy loam sec. 17, T. 7 S., R. 18 E. Gravel content—35 to 50 percent Range in Characteristics Cobble content—20 to 45 percent Profile: McCain Series Depth to bedrock—20 to 40 inches Particle-size control section: Depth class: Moderately deep to basalt Clay content—18 to 30 percent Drainage class: Well drained Permeability: Moderately slow A horizon: Position on landscape: Terraces Value—5 or 6 dry, 3 or 4 moist Parent material: Kind—alluvium; source—mixed Chroma—2 or 3 Slope range: 1 to 6 percent Gravel content—0 to 10 percent Elevation: 3,500 to 4,500 feet Bt horizon: Average annual precipitation: 9 to 10 inches Value—5 or 6 dry, 4 or 5 moist Average annual air temperature: 47 to 49 Chroma—3 or 4 degrees F Texture—silt loam or silty clay loam Frost-free period: 130 to 140 days Bk horizon: Taxonomic class: Fine-silty, mixed, mesic Value—6 or 7 dry, 4 or 5 moist Xerollic Haplargids Chroma—2 to 4 Gravel content—0 to 10 percent Typical Pedon Durinode content—0 to 20 percent A—0 to 6 inches; brown (10YR 5/3) silt loam, dark brown (10YR 3/3) moist; moderate fine Minidoka Series granular structure; soft, friable, slightly sticky and slightly plastic; many very fine and fine Depth class: Moderately deep to a duripan roots; many very fine and fine interstitial Drainage class: Well drained pores; 5 percent gravel; neutral; clear smooth Permeability: Moderate boundary. Position on landscape: Terraces Bt—6 to 16 inches; yellowish brown (10YR 5/4) Parent material: Kind—alluvium; source—mixed silt loam, brown (10YR 4/3) moist; moderate Slope range: 0 to 4 percent medium subangular blocky structure; hard, Elevation: 3,500 to 4,500 feet friable, slightly sticky and slightly plastic; Average annual precipitation: 8 to 10 inches common very fine and fine roots; common Average annual air temperature: 48 to 50 fine tubular pores; few faint clay films on degrees F faces of peds and in pores; 5 percent Frost-free period: 120 to 140 days gravel; mildly alkaline; abrupt smooth Taxonomic class: Coarse-silty, mixed, mesic boundary. Xerollic Durorthids Bk—16 to 23 inches; very pale brown (10YR 7/3) silt loam, yellowish brown (10YR 5/4) moist; Typical Pedon massive; very hard, friable; few very fine Ap—0 to 6 inches; pale brown (10YR 6/3) silt roots; common very fine and fine irregular loam, brown (10YR 4/3) moist; weak fine pores; 10 percent gravel; 10 percent granular structure; slightly hard, friable; many durinodes; strongly effervescent (20 percent very fine to medium roots; many very fine calcium carbonate equivalent); moderately tubular pores; strongly effervescent; mildly alkaline; abrupt smooth boundary. alkaline; gradual wavy boundary. R—23 inches; fractured basalt; lime coatings on Bk—6 to 13 inches; pale brown (10YR 6/3) silt surface and in fractures. loam, brown (10YR 4/3) moist; weak medium subangular blocky structure; slightly hard, Typical Pedon Location friable; many very fine to medium roots; Map unit in which located: Power-McCain many very fine tubular pores; strongly complex, 1 to 6 percent slopes effervescent; moderately alkaline; abrupt Location in survey area: About 10 miles northeast smooth boundary. 198 Soil Survey

Bkq1—13 to 20 inches; light gray (10YR 7/2) silt Average annual precipitation: 8 to 10 inches loam, grayish brown (10YR 5/2) moist; Average annual air temperature: 48 to 50 massive; hard, firm; common very fine and degrees F fine roots; common very fine tubular pores; Frost-free period: 120 to 140 days 25 percent durinodes; violently effervescent; Taxonomic class: Loamy, mixed, mesic, shallow moderately alkaline; gradual wavy boundary. Xerollic Durorthids Bkq2—20 to 26 inches; light gray (10YR 7/2) silt loam, grayish brown (10YR 5/2) moist; Typical Pedon massive; hard, firm; common very fine and Ap—0 to 3 inches; pale brown (10YR 6/3) silt fine roots; common very fine tubular pores; loam, brown (10YR 4/3) moist; weak fine 10 percent gravel-sized duripan fragments; 15 granular structure; slightly hard, friable, percent durinodes; violently effervescent; slightly sticky and slightly plastic; many fine moderately alkaline; abrupt smooth boundary. roots; many fine vesicular pores; strongly Bkqm—26 to 40 inches; white (10YR 8/2) effervescent; moderately alkaline; gradual indurated duripan, light gray (10YR 7/2) wavy boundary. moist; extremely hard, extremely firm; many Bk1—3 to 8 inches; pale brown (10YR 6/3) silt continuous silica-cemented laminations loam, brown (10YR 4/3) moist; weak medium throughout duripan; violently effervescent; subangular blocky structure; slightly hard, abrupt smooth boundary. friable, slightly sticky and slightly plastic; 2R—40 inches; basalt. many fine roots; common very fine and fine Typical Pedon Location tubular pores; strongly effervescent; moderately alkaline; gradual wavy boundary. Map unit in which located: Minidoka silt loam, 2 Bk2—8 to 15 inches; very pale brown (10YR 7/3) to 4 percent slopes silt loam, brown (10YR 5/3) moist; weak Location in survey area: About 5 miles east of 1 1 1 medium subangular blocky structure; hard, Castleford, Idaho; in the NW /4NW /4NW /4 of very friable; many fine roots; common very sec. 25, T. 10 S., R. 14 E. fine and fine tubular pores; violently effervescent; moderately alkaline; abrupt Range in Characteristics smooth boundary. Profile: Bkqm—15 to 30 inches; white (10YR 8/2) Depth to bedrock—40 to 60 inches indurated duripan, light gray (10YR 7/2) Depth to duripan—20 to 40 inches moist; massive; extremely hard, extremely Depth to secondary lime—7 to 16 inches firm; many continuous silica-cemented laminations throughout duripan; violently Ap horizon: effervescent; abrupt smooth boundary. Value—6 or 7 dry, 4 or 5 moist 2R—30 inches; basalt. Chroma—2 or 3 Typical Pedon Location Bkq horizon: Value—6 to 8 dry, 4 or 5 moist Map unit in which located: Minveno silt loam, 2 to Chroma—2 or 3 8 percent slopes Calcium carbonate equivalent—15 to 40 percent Location in survey area: About 3 miles north of 1 1 1 Durinode content—5 to 40 percent Hansen, Idaho; in the SE /4SW /4NE /4 of sec. Reaction—moderately alkaline or strongly 12, T. 10 S., R. 18 E. alkaline Range in Characteristics Minveno Series Profile: Depth to bedrock—20 to 40 inches Depth class: Shallow to a duripan Depth to duripan—10 to 20 inches Drainage class: Well drained Ap horizon: Permeability: Moderate Chroma—2 or 3 Position on landscape: Terraces Parent material: Kind—alluvium; source—mixed Bk horizon: Slope range: 0 to 20 percent Value—6 or 7 dry, 4 or 5 moist Elevation: 3,500 to 4,500 feet Chroma—2 or 3 Jerome-Twin Falls, Idaho 199

Texture—silt loam or loam Typical Pedon Location Reaction—mildly alkaline or moderately alkaline Map unit in which located: Mug very cobbly loam, 2 to 10 percent slopes Mug Series Location in survey area: About 21 miles southwest of Rogerson, Idaho; in the 1 1 1 Depth class: Moderately deep to welded tuff SW /4SW /4SW /4 of sec. 6, T. 15 S., Drainage class: Well drained R. 13 E. Permeability: Very slow Position on landscape: Terraces Range in Characteristics Parent material: Kind—colluvium and residuum; Profile: source—welded tuff Depth to bedrock—20 to 30 inches Slope range: 2 to 10 percent Thickness of mollic epipedon—9 to 15 inches Elevation: 5,600 to 6,300 feet Rock fragment content—40 to 75 percent Average annual precipitation: 12 to 15 Base saturation—65 to 75 percent inches Average annual air temperature: 43 to 45 Particle-size control section: degrees F Clay content—45 to 55 percent Frost-free period: 90 to 100 days A horizon: Taxonomic class: Clayey-skeletal, Value—4 or 5 dry montmorillonitic, frigid Ultic Palexerolls Chroma—1 to 3 Typical Pedon Bt1 horizon: Chroma—2 or 3 A—0 to 5 inches; grayish brown (10YR 5/2) very Texture—extremely gravelly clay loam or very cobbly loam, very dark grayish brown (10YR gravelly clay 3/2) moist; weak medium platy structure; Gravel content—35 to 50 percent slightly hard, friable, slightly sticky and Cobble content—5 to 30 percent slightly plastic; many roots; many very fine tubular pores; 20 percent gravel and 20 2Bt2 horizon: percent cobbles; slightly acid; abrupt smooth Hue—10YR or 7.5YR boundary. Value—4 or 5 dry Bt1—5 to 14 inches; grayish brown (10YR 5/2) Chroma—2 to 4 extremely gravelly clay loam, very dark Gravel content—15 to 25 percent grayish brown (10YR 3/2) moist; strong fine Cobble content—5 to 10 percent angular blocky structure; hard, firm, sticky Reaction—slightly acid or neutral and plastic; common fine and very fine roots; common very fine tubular pores; common distinct clay films on faces of peds and in Nawt Series pores; 40 percent gravel and 30 percent Depth class: Deep to welded tuff cobbles; slightly acid; abrupt smooth Drainage class: Well drained boundary. Permeability: Slow 2Bt2—14 to 25 inches; brown (7.5YR 5/4) Position on landscape: Breaks gravelly clay, dark brown (7.5YR 4/4) moist; Parent material: Kind—colluvium and strong coarse prismatic structure; extremely residuum; source—welded tuff and volcanic hard, very firm, very sticky and very plastic; ash few very fine and fine roots; few very fine Slope range: 15 to 75 percent tubular pores; many prominent clay films on Elevation: 4,300 to 6,000 feet faces of peds and in pores; 20 percent gravel Average annual precipitation: 12 to 16 inches and 5 percent cobbles; neutral; abrupt smooth Average annual air temperature: 47 to 50 boundary. degrees F 2R—25 inches; gray (10YR 6/1) welded tuff, dark Frost-free period: 100 to 110 days gray (10YR 4/1) moist; thin inconsistent calcium carbonate and silica coating on Taxonomic class: Fine, montmorillonitic, mesic surface. Ultic Palexerolls 200 Soil Survey

Typical Pedon outcrop association, 30 to 75 percent slopes A—0 to 5 inches; brown (10YR 5/3) extremely Location in survey area: About 8 miles east of stony loam, dark brown (10YR 3/3) moist; 1 1 1 Hollister, Idaho; in the NW /4NE /4SW /4 of moderate fine platy structure parting to weak sec. 24, T. 12 S., R. 17 E. fine granular; soft, very friable, slightly sticky and slightly plastic; many very fine and fine Range in Characteristics roots; many very fine tubular pores; 30 Profile: percent gravel, 5 percent cobbles, and 30 Depth to bedrock—40 to 60 inches percent stones; neutral; abrupt smooth Thickness of mollic epipedon—10 to 18 boundary. inches Bt1—5 to 10 inches; brown (10YR 5/3) gravelly Base saturation—65 to 75 percent clay, dark brown (10YR 3/3) moist; moderate fine to medium subangular blocky structure; Particle-size control section: hard, firm, very sticky and very plastic; many Clay content—40 to 50 percent fine and very fine roots; many very fine A horizon: tubular pores; many distinct clay films on Value—4 or 5 dry, 2 or 3 moist faces of peds and in pores; 15 percent gravel; Chroma—2 or 3 neutral; clear smooth boundary. Bt2—10 to 18 inches; brown (7.5YR 5/4) gravelly Bt horizon: clay, dark brown (7.5YR 4/4) moist; strong Hue—10YR or 7.5YR medium subangular blocky structure parting Value—5 or 6 dry, 3 or 4 moist to weak medium prismatic; very hard, firm, Chroma—3 or 4 very sticky and very plastic; common fine Texture—gravelly silty clay, gravelly clay, or and very fine roots; common very fine tubular stony clay pores; many distinct clay films on faces of Gravel content—10 to 20 percent peds and in pores; 20 percent gravel and 5 Cobble content—0 to 5 percent percent cobbles; neutral; clear smooth Stone content—0 to 5 percent boundary. Bk horizon: Bt3—18 to 36 inches; light yellowish brown (10YR Value—6 or 7 dry, 4 or 5 moist 6/4) gravelly clay, brown (7.5YR 5/4) moist; Chroma—3 or 4 moderate medium subangular blocky Texture—gravelly loam, gravelly silt loam, or very structure; very hard, very firm, sticky and gravelly clay loam plastic; common fine and very fine roots; Calcium carbonate equivalent—5 to 15 percent common very fine tubular pores; common Gravel content—30 to 45 percent faint clay films on faces of peds and in pores; Cobble content—0 to 10 percent 10 percent gravel, 5 percent cobbles, and 5 percent stones; mildly alkaline; clear smooth boundary. Oshone Series Bk—36 to 45 inches; very pale brown (10YR 7/4) Depth class: Moderately deep to a duripan very gravelly clay loam, yellowish brown Drainage class: Well drained (10YR 5/4) moist; moderate medium Permeability: Ver y slow subangular blocky structure; hard, firm, Position on landscape: Terraces sticky and plastic; few very fine roots; few Parent material: Kind—alluvium and very fine tubular pores; 45 percent gravel and colluvium; source—welded tuff and 10 percent cobbles; strongly effervescent in volcanic ash veins; lime segregated in common rounded Slope range: 2 to 10 percent fine filaments; moderately alkaline; clear Elevation: 5,500 to 6,100 feet smooth boundary. Average annual precipitation: 12 to 16 inches Cr—45 to 62 inches; brown (7.5YR 4/2) Average annual air temperature: 42 to 45 decomposing lime-coated vesicular welded degrees F tuff, dark reddish brown (5YR 3/3) moist. Frost-free period: 90 to 105 days Typical Pedon Location Taxonomic class: Fine, montmorillonitic, frigid Map unit in which located: Stricker-Nawt-Rock Typic Durixerolls Jerome-Twin Falls, Idaho 201

Typical Pedon cemented very gravelly sand; 80 percent gravel; few fine roots; strongly effervescent. A—0 to 2 inches; grayish brown (10YR 5/2) clay loam, very dark grayish brown (10YR 3/2) Typical Pedon Location moist; moderate medium platy structure; Map unit in which located: Oshone complex, 2 to slightly hard, friable, sticky and plastic; 10 percent slopes (fig. 12) common very fine, fine, and medium roots; common very fine and fine vesicular pores; 10 percent gravel; slightly acid; abrupt smooth boundary. AB—2 to 6 inches; brown (10YR 5/3) clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium subangular blocky structure; hard, friable, sticky and plastic; common very fine, fine, and medium roots; common very fine and fine tubular pores; 10 percent gravel; slightly acid; gradual wavy boundary. Bt1—6 to 16 inches; brown (10YR 5/3) clay, very dark grayish brown (10YR 3/2) moist; strong medium angular blocky structure; very hard, firm, very sticky and very plastic; common fine and medium roots; common very fine and fine tubular pores; many distinct clay films on faces of peds and in pores; 10 percent gravel; slightly acid; abrupt smooth boundary. Bt2—16 to 27 inches; brown (10YR 5/3) gravelly Figure 12.—Profile of Oshone clay loam in an area of clay, dark brown (10YR 4/3) moist; moderate Oshone complex, 2 to 10 percent slopes. medium columnar structure parting to moderate medium angular blocky; very hard, Location in survey area: About 13 miles very firm, very sticky and very plastic; few southeast of Rogerson, Idaho; in the fine roots; few very fine and fine tubular 1 1 1 NE /4NE /4NW /4 of sec. 2, T. 16 S., pores; many prominent clay films on faces of R. 17 E. peds and in pores; 15 percent gravel; neutral; abrupt smooth boundary. Range in Characteristics Bt3—27 to 38 inches; light brown (7.5YR 6/4) Profile: very gravelly clay loam, dark brown Depth to bedrock—more than 60 inches (7.5YR 4/4) moist; moderate medium Depth to duripan—20 to 40 inches subangular blocky structure; hard, firm, Thickness of mollic epipedon—7 to 16 inches sticky and plastic; few fine roots; few very fine and fine tubular pores; many distinct clay Particle-size control section: films on faces of peds and in pores; 40 Clay content—45 to 55 percent percent gravel; neutral; abrupt smooth A horizon: boundary. Value—4 or 5 dry, 2 or 3 moist Bqm—38 to 47 inches; very pale brown Chroma—2 or 3 (10YR 8/3) indurated duripan, very pale brown Gravel content—5 to 15 percent (10YR 7/3) moist; massive; extremely hard, extremely firm; continuous silica-laminated Bt1 and Bt2 horizons: cap over strongly cemented material; sand Hue—7.5YR or 10YR and gravel is extremely hard and extremely Value—3 to 6 dry, 3 or 4 moist firm when moist; few fine roots in fractures of Chroma—2 to 4 1 duripan; fractures /4 inch wide and 6 inches Texture—clay, gravelly clay, or clay loam apart; gradual smooth boundary. Gravel content—5 to 25 percent 2Bkq—47 to 60 inches; multicolored weakly Reaction—slightly acid or neutral 202 Soil Survey

Bqm horizon: percent calcium carbonate equivalent); 1 Thickness of upper silica lamination— /8 to 1 inch moderately alkaline; abrupt smooth 1 Thickness of lower silica laminations— /8 inch to boundary. 2 inches 2Bk2—23 to 41 inches; very pale brown (10YR Thickness of duripan—5 to 10 inches 7/3) loam, brown (10YR 5/3) moist; massive; very hard, friable, slightly sticky and slightly Owinza Series plastic; few very fine tubular pores; 5 percent gravel; violently effervescent (10 percent Depth class: Very deep calcium carbonate equivalent); moderately Drainage class: Well drained alkaline; abrupt smooth boundary. Permeability: Very slow 2Bk3—41 to 63 inches; very pale brown (10YR Position on landscape: Depressions in terraces 8/3) loam, light yellowish brown (10YR 6/4) Parent material: Kind—alluvium; source—mixed moist; massive; slightly hard, friable, slightly Slope range: 1 to 3 percent sticky and slightly plastic; few very fine Elevation: 3,500 to 4,500 feet tubular pores; 10 percent gravel; violently Average annual precipitation: 9 to 11 inches effervescent (52 percent calcium carbonate Average annual air temperature: 49 to 51 equivalent); moderately alkaline. degrees F Typical Pedon Location Frost-free period: 120 to 140 days Map unit in which located: Power-Owinza-Rock Taxonomic class: Fine, montmorillonitic, mesic outcrop complex, 1 to 8 percent slopes Xerollic Natrargids Location in survey area: About 11 miles Typical Pedon northeast of Hazelton, Idaho; in the 1 1 1 SE /4SE /4SE /4 of sec. 21, T. 8 S., A—0 to 4 inches; very pale brown (10YR 7/3) silt R. 21 E. loam, brown (10YR 4/3) moist; strong medium platy structure; soft, very friable, Range in Characteristics slightly sticky and slightly plastic; few very fine, fine, and medium roots; common fine, Profile: medium, and coarse vesicular pores; neutral; Depth to bedrock—more than 60 inches abrupt smooth boundary. Depth to secondary lime—12 to 21 inches Btn1—4 to 10 inches; yellowish brown (10YR 5/4) Particle-size control section: clay, yellowish brown (10YR 5/4) moist; Clay content—39 to 48 percent strong medium columnar structure; extremely Sodium absorption ratio—20 to 40 percent hard, very firm, very sticky and very plastic; few very fine, fine, and medium roots; few A horizon: very fine tubular pores; many prominent clay Value—6 or 7 dry, 3 to 5 moist films on faces of peds and in pores; slightly Chroma—2 or 3 effervescent; moderately alkaline; clear wavy Reaction—neutral or mildly alkaline boundary. Btn horizon: Btn2—10 to 16 inches; very pale brown (10YR Value—5 to 7 dry, 4 or 5 moist 7/3) clay, brown (10YR 5/3) moist; moderate Chroma—3 or 4 medium angular blocky structure; very hard, Texture—clay or clay loam firm, very sticky and very plastic; few very Reaction—mildly alkaline or moderately fine, fine, and medium roots; few very fine alkaline tubular pores; many prominent clay films on faces of peds and in pores; strongly Bk1 and 2Bk2 horizons: effervescent (8 percent calcium carbonate Value—6 to 8 dry, 4 to 6 moist equivalent); moderately alkaline; abrupt Chroma—2 to 4 smooth boundary. Texture—silty clay loam, loam, or gravelly Bk1—16 to 23 inches; white (10YR 8/2) silty clay loam loam, pale brown (10YR 6/3) moist; massive; Gravel content—0 to 20 percent very hard, firm, sticky and plastic; few very Cobble content—0 to 5 percent fine, fine, and medium roots; few very fine Reaction—moderately alkaline or strongly tubular pores; violently effervescent (17 alkaline Jerome-Twin Falls, Idaho 203

Owsel Series Bk—52 to 68 inches; very pale brown (10YR 8/3) sandy loam, pale brown Depth class: Very deep (10YR 6/3) moist; massive; slightly hard, Drainage class: Well drained friable, slightly sticky and slightly plastic; few Permeability: Moderately slow fine roots; few fine tubular pores; 5 percent Position on landscape: Terraces cobbles; violently effervescent; strongly Parent material: Kind—alluvium; source—mixed alkaline. Slope range: 0 to 20 percent Typical Pedon Location Elevation: 3,500 to 5,500 feet Average annual precipitation: 8 to 12 inches Map unit in which located: Owsel silt loam, 4 to 8 Average annual air temperature: 47 to 50 percent slopes degrees F Location in survey area: About 10 miles west of 1 1 1 Frost-free period: 110 to 140 days Rogerson, Idaho; in the SW /4SW /4SW /4 of sec. 2, T. 14 S., R. 14 E. Taxonomic class: Fine-silty, mixed, mesic Durixerollic Haplargids Range in Characteristics Typical Pedon Profile: A—0 to 3 inches; pale brown (10YR 6/3) silt Depth to bedrock—more than 60 inches loam, dark brown (10YR 3/3) moist; moderate Depth to carbonates—10 to 40 inches medium platy structure; slightly hard, friable, Clay content—24 to 35 percent slightly sticky and slightly plastic; many very A horizon: fine and fine roots; common very fine and Value—5 or 6 dry fine tubular pores; neutral; abrupt smooth Chroma—2 to 4 boundary. Reaction—neutral or mildly alkaline BA—3 to 9 inches; pale brown (10YR 6/3) silt loam, dark brown (10YR 3/3) moist; weak Bt horizon: medium subangular blocky structure; hard, Value—4 to 6 dry friable, slightly sticky and slightly plastic; Chroma—2 or 3 common very fine and fine roots; common Texture—silt loam or silty clay loam very fine and fine tubular pores; neutral; clear Bkq horizon: smooth boundary. Value—6 or 7 dry Bt1—9 to 18 inches; pale brown (10YR 6/3) silty Chroma—2 or 3 clay loam, brown (10YR 4/3) moist; moderate Texture—fine sandy loam, loam, or silt loam medium subangular blocky structure; hard, Reaction—moderately alkaline or strongly firm, sticky and plastic; common very fine alkaline and fine roots; many very fine to medium tubular pores; common distinct clay films on faces of peds and in pores; neutral; clear Paniogue Series wavy boundary. Depth class: Very deep Bt2—18 to 26 inches; pale brown (10YR 6/3) silt Drainage class: Well drained loam, brown (10YR 4/3) moist; moderate Permeability: Moderate medium angular blocky structure; very hard, Position on landscape: Terraces firm, slightly sticky and slightly plastic; Parent material: Kind—old alluvium; source— common fine roots; common very fine tubular mixed pores; few faint clay films on faces of peds Slope range: 0 to 4 percent and in pores; mildly alkaline; abrupt smooth Elevation: 2,800 to 4,000 feet boundary. Average annual precipitation: 8 to 10 inches Bkq—26 to 52 inches; very pale brown (10YR Average annual air temperature: 49 to 51 7/3) loam, brown (10YR 5/3) moist; massive; degrees F very hard, very firm, slightly sticky and Frost-free period: 120 to 140 days slightly plastic; few fine roots; few fine tubular pores; 25 percent durinodes; strongly Taxonomic class: Coarse-loamy over sandy or effervescent; moderately alkaline; clear sandy-skeletal, mixed, mesic Xerollic smooth boundary. Camborthids 204 Soil Survey

Typical Pedon Reaction—mildly alkaline or moderately alkaline A—0 to 5 inches; brown (10YR 5/3) loam, dark Bk horizon: brown (10YR 3/3) moist; weak fine granular Value—6 or 7 dry, 5 or 6 moist structure; soft, friable; common very fine and Chroma—2 to 4 fine roots; many very fine tubular pores; Texture—very fine sandy loam or loam neutral; gradual wavy boundary. Bw1—5 to 14 inches; pale brown (10YR 6/3) very Paulville Series fine sandy loam, brown (10YR 4/3) moist; weak medium subangular blocky structure; Depth class: Very deep slightly hard, friable; common very fine and Drainage class: Well drained fine roots; many very fine tubular pores; Permeability: Moderately slow mildly alkaline; gradual wavy boundary. Position on landscape: Terraces Bw2—14 to 25 inches; light yellowish brown Parent material: Kind—alluvium; source—mixed (10YR 6/4) very fine sandy loam, brown Slope range: 0 to 6 percent (10YR 4/3) moist; moderate medium Elevation: 3,500 to 5,000 feet subangular blocky structure; slightly hard, Average annual precipitation: 8 to 11 inches friable; few very fine roots; common Average annual air temperature: 47 to 51 very fine tubular pores; slightly degrees F effervescent; moderately alkaline; gradual Frost-free period: 110 to 140 days wavy boundary. Taxonomic class: Fine-loamy, mixed, mesic Bk—25 to 35 inches; very pale brown (10YR 7/3) Xerollic Haplargids sandy loam, brown (10YR 5/3) moist; moderate medium subangular blocky Typical Pedon structure; hard, friable; few very fine roots; few very fine tubular pores; strongly Ap1—0 to 3 inches; brown (10YR 4/3) loam, dark effervescent; moderately alkaline; abrupt brown (10YR 3/3) moist; weak fine granular smooth boundary. structure; slightly hard, friable; common very 2Bk2—35 to 60 inches; multicolored very gravelly fine and fine roots; common very fine and sand; single grain; 45 percent gravel; loose; fine tubular pores; neutral; clear smooth lime coatings on underside of gravel; strongly boundary. effervescent; moderately alkaline. Ap2—3 to 8 inches; brown (10YR 4/3) loam, dark brown (10YR 3/3) moist; weak medium Typical Pedon Location subangular blocky structure; slightly hard, Map unit in which located: Paniogue loam, 2 to 4 friable; common very fine and fine roots; percent slopes common very fine and fine tubular pores; Location in survey area: About 24 miles neutral; clear smooth boundary. northwest of Buhl, Idaho; in the Bt1—8 to 17 inches; yellowish brown (10YR 5/4) 1 1 1 NE /4SE /4SE /4 of sec. 11, T. 6 S., R. 12 E. loam, brown (10YR 4/3) moist; moderate medium subangular blocky structure; slightly Range in Characteristics hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; Profile: common fine tubular pores; few faint clay Depth to bedrock—more than 60 inches films on faces of peds and in pores; mildly Depth to contrasting textures—20 to 40 inches alkaline; clear smooth boundary. Particle-size control section: Bt2—17 to 31 inches; yellowish brown (10YR 5/4) Clay content—6 to 14 percent loam, brown (10YR 4/3) moist; moderate medium subangular blocky structure; slightly A horizon: hard, friable, slightly sticky and slightly Value—5 or 6 dry, 3 or 4 moist plastic; common very fine roots; common Chroma—2 or 3 very fine tubular pores; common faint clay Bw horizon: films on faces of peds and in pores; mildly Value—5 to 7 dry, 4 or 5 moist alkaline; gradual smooth boundary. Chroma—2 to 4 Bk1—31 to 40 inches; very pale brown (10YR Texture—very fine sandy loam or loam 7/3) loam, yellowish brown (10YR 5/4) moist; Jerome-Twin Falls, Idaho 205

moderate medium subangular blocky Frost-free period: 100 to 110 days structure; slightly hard, friable; few very fine Taxonomic class: Fine, montmorillonitic, mesic roots; few very fine tubular pores; 5 percent Abruptic Xerollic Durargids gravel; strongly effervescent; moderately alkaline; gradual wavy boundary. Typical Pedon Bk2—40 to 47 inches; light yellowish brown A1—0 to 3 inches; pale brown (10YR 6/3) silt (10YR 6/4) loam, yellowish brown (10YR 5/4) loam, dark brown (10YR 3/3) moist; moderate moist; moderate medium subangular blocky coarse platy structure; hard, friable, slightly structure; slightly hard, friable; few very fine sticky and slightly plastic; many very fine to roots; few very fine tubular pores; 5 percent medium roots; many very fine tubular pores; gravel; strongly effervescent; moderately neutral; abrupt smooth boundary. alkaline; abrupt smooth boundary. A2—3 to 7 inches; pale brown (10YR 6/3) Bk3—47 to 60 inches; pale brown (10YR 6/3) silty clay loam, dark brown (10YR 3/3) gravelly loam, yellowish brown (10YR 5/4) moist; moderate medium platy structure; moist; massive; hard, firm; few very fine hard, friable, sticky and plastic; many tubular pores; 20 percent gravel; strongly very fine to medium roots; many very fine effervescent; moderately alkaline. tubular pores; neutral; abrupt smooth Typical Pedon Location boundary. Bt—7 to 18 inches; pale brown (10YR 6/3) silty Map unit in which located: Paulville-Idow clay, brown (10YR 4/3) moist; strong coarse complex, 1 to 4 percent slopes prismatic structure; very hard, very firm, Location in survey area: About 6 miles north of 1 1 1 very sticky and very plastic; few very fine Jerome, Idaho; in the NW /4NW /4NE /4 of and fine roots; few very fine tubular pores; sec. 24, T. 7 S., R. 16 E. many prominent clay films on faces of Range in Characteristics peds and in pores; neutral; abrupt wavy boundary. Profile: Bkq—18 to 32 inches; very pale brown (10YR Depth to bedrock—more than 60 inches 8/3) loam, pale brown (10YR 6/3) moist; Depth to secondary lime—27 to 32 inches massive; very hard, firm, slightly sticky and Ap1 horizon: slightly plastic; few very fine roots; few very Value—4 to 6 dry, 3 or 4 moist fine tubular pores; 5 percent gravel; violently effervescent (18 percent calcium carbonate Bt horizon: equivalent); moderately alkaline; abrupt Value—5 or 6 dry, 3 or 4 moist smooth boundary. Chroma—3 or 4 Bkqm—32 to 60 inches; white (10YR 8/1) Texture—silt loam, clay loam, or loam fractured duripan, very pale brown (10YR 7/3) Clay content—24 to 31 percent moist; platy; indurated; extremely hard, 1 Bk horizon: extremely firm; many /2- to 3-inch-thick lime- Value—6 to 8 dry, 5 or 6 moist and silica-cemented laminations with sandy Chroma—2 to 4 loam between laminations; few very fine roots 1 Texture—silt loam, loam, or gravelly loam in fractures of duripan; fractures /4 inch wide and 8 inches apart; violently effervescent; Pigtail Series moderately alkaline. Typical Pedon Location Depth class: Moderately deep to a duripan Drainage class: Well drained Map unit in which located: Tanner-Pigtail complex, Permeability: Very slow 1 to 8 percent slopes Position on landscape: Depressions in terraces Location in survey area: About 20 miles west of 1 1 1 Parent material: Kind—alluvium; source—mixed Rogerson, Idaho; in the NE /4NW /4NE /4 of Slope range: 1 to 3 percent sec. 6, T. 14 S., R. 13 E. Elevation: 4,600 to 5,500 feet Range in Characteristics Average annual precipitation: 9 to 12 inches Average annual air temperature: 46 to 48 Profile: degrees F Depth to bedrock—more than 60 inches 206 Soil Survey

Depth to duripan—20 to 40 inches extremely gravelly clay, dark brown (10YR 4/3) moist; strong medium angular blocky Particle-size control section: structure; very hard, very firm, very sticky Clay content—45 to 55 percent and very plastic; few very fine roots; few very A1 horizon: fine tubular pores; many prominent clay films Value—5 or 6 dry, 3 or 4 moist on faces of peds and in pores; 60 percent Chroma—2 or 3 gravel and 5 percent cobbles; slightly acid; abrupt smooth boundary. Bt horizon: Bt3—22 to 45 inches; light yellowish brown (10YR Value—6 or 7 dry, 4 or 5 moist 6/4) extremely gravelly clay, dark yellowish Chroma—2 to 4 brown (10YR 4/4) moist; strong fine angular Bkqm horizon: blocky structure; very hard, very firm, very 1 Thickness of upper silica lamination— /2 inch to sticky and very plastic; few very fine roots; 1 3 /2 inches few very fine tubular pores; many prominent Thickness of lower silica laminations—1 inch to 6 clay films on faces of peds and in pores; 70 inches percent gravel and 5 percent cobbles; neutral; Cementation between laminations—weak or clear smooth boundary. strong 2Bt4—45 to 60 inches; light brown (7.5YR 6/4) Thickness of duripan—21 to 40 inches or more extremely gravelly clay, brown (7.5YR 4/4) moist; strong fine angular blocky structure; Player Series very hard, very firm, very sticky and very plastic; few very fine tubular pores; many Depth class: Very deep prominent clay films on faces of peds and in Drainage class: Well drained pores; 60 percent gravel and 5 percent Permeability: Very slow cobbles; neutral. Position on landscape: Breaks Typical Pedon Location Parent material: Kind—colluvium; source—welded tuff Map unit in which located: Player-Rock outcrop Slope range: 30 to 75 percent complex, 30 to 75 percent slopes Elevation: 5,400 to 6,400 feet Location in survey area: About 19 miles Average annual precipitation: 12 to 15 inches southwest of Rogerson, Idaho; in the 1 1 1 Average annual air temperature: 40 to 44 NE /4NW /4NE /4 of sec. 29, T. 16 S., R. 14 E. degrees F Range in Characteristics Frost-free period: 70 to 80 days Profile: Taxonomic class: Clayey-skeletal, Depth to bedrock—more than 60 inches montmorillonitic, frigid Ultic Palexerolls Thickness of mollic epipedon—10 to 20 inches Typical Pedon Rock fragment content—45 to 75 percent Base saturation—55 to 65 percent A—0 to 5 inches; dark grayish brown (10YR 4/2) very gravelly loam, black (10YR 2/1) moist; Particle-size control section: moderate fine granular structure; slightly Clay content—45 to 60 percent hard, friable, slightly sticky and slightly A horizon: plastic; many roots; many very fine tubular Value—3 or 4 dry, 2 to 4 moist pores; 30 percent gravel and 15 percent Chroma—1 or 2 cobbles; neutral; gradual smooth boundary. Bt1—5 to 11 inches; dark grayish brown (10YR Bt horizon: 4/2) very gravelly clay, very dark grayish Hue—10YR or 7.5YR brown (10YR 3/2) moist; moderate medium Value—3 to 6 dry, 2 to 4 moist subangular blocky structure; hard, firm, Chroma—2 to 4 sticky and plastic; common roots; many very Texture—very gravelly clay or extremely gravelly fine tubular pores; common distinct clay films clay on faces of peds and in pores; 55 percent Gravel content—40 to 70 percent gravel; slightly acid; clear smooth boundary. Cobble content—0 to 10 percent Bt2—11 to 22 inches; brown (10YR 5/3) Reaction—slightly acid or neutral Jerome-Twin Falls, Idaho 207

Portneuf Series Range in Characteristics Profile: Depth class: Very deep Depth to bedrock—more than 60 inches Drainage class: Well drained Permeability: Moderately slow Ap horizon: Position on landscape: Terraces Value—5 or 6 dry, 3 or 4 moist Parent material: Kind—alluvium; source—mixed Chroma—2 or 3 Slope range: 0 to 12 percent Bk horizon: Elevation: 3,000 to 4,500 feet Value—5 to 7 dry, 4 to 6 moist Average annual precipitation: 8 to 10 inches Chroma—2 or 3 Average annual air temperature: 48 to 51 Reaction—mildly alkaline or moderately alkaline degrees F Frost-free period: 110 to 140 days Bkq horizon: Value—6 or 7 dry, 4 or 5 moist Taxonomic class: Coarse-silty, mixed, mesic Chroma—2 or 3 Durixerollic Calciorthids Durinode content—15 to 30 percent Typical Pedon Reaction—moderately alkaline or strongly alkaline Ap—0 to 5 inches; light brownish gray (10YR 6/2) silt loam, dark grayish brown (10YR 4/2) moist; weak fine granular structure; slightly Power Series hard, friable; many very fine and fine roots; Depth class: Very deep many very fine and fine tubular pores; mildly Drainage class: Well drained alkaline; gradual wavy boundary. Permeability: Moderately slow Bk—5 to 15 inches; pale brown (10YR 6/3) silt Position on landscape: Terraces loam, brown (10YR 4/3) moist; weak medium Parent material: Kind—alluvium; source—mixed subangular blocky structure; hard, friable; Slope range: 1 to 8 percent common very fine and fine roots; common Elevation: 3,500 to 4,500 feet very fine and fine tubular pores; 5 percent Average annual precipitation: 9 to 11 inches durinodes; strongly effervescent; moderately Average annual air temperature: 47 to 49 alkaline; gradual wavy boundary. degrees F Bkq1—15 to 24 inches; very pale brown (10YR Frost-free period: 130 to 140 days 7/3) silt loam, brown (10YR 5/3) moist; weak medium subangular blocky structure; hard, Taxonomic class: Fine-silty, mixed, mesic friable; few very fine and fine roots; common Xerollic Haplargids very fine and fine tubular pores; 15 percent Typical Pedon durinodes; strongly effervescent; moderately alkaline; clear smooth boundary. A—0 to 8 inches; pale brown (10YR 6/3) silt Bkq2—24 to 40 inches; very pale brown (10YR loam, dark brown (10YR 3/3) moist; weak 7/3) silt loam, brown (10YR 5/3) moist; medium platy structure; slightly hard, friable, massive; very hard, firm; few very fine roots; slightly sticky and slightly plastic; many common very fine tubular pores; 35 percent roots; many very fine and fine tubular pores; durinodes; strongly effervescent; moderately neutral; clear wavy boundary. alkaline; clear smooth boundary. Bt—8 to 20 inches; light yellowish brown (10YR 2Bk—40 to 60 inches; pale brown (10YR 6/3) silt 6/4) silt loam, brown (10YR 4/3) moist; loam, brown (10YR 4/3) moist; massive; moderate medium subangular blocky slightly hard, friable; strongly effervescent; structure; hard, firm, sticky and plastic; many moderately alkaline. roots; common very fine and fine tubular pores; common distinct clay films on faces of Typical Pedon Location peds and in pores; moderately alkaline; Map unit in which located: Portneuf silt loam, 2 to abrupt smooth boundary. 4 percent slopes Bk1—20 to 34 inches; white (10YR 8/2) loam, Location in survey area: About 4 miles southeast brown (10YR 5/3) moist; massive; extremely 1 1 1 of Hazelton, Idaho; in the NE /4NE /4SE /4 of hard, very firm, slightly sticky; few very fine sec. 14, T. 10 S., R. 20 E. and fine roots; common very fine tubular 208 Soil Survey

pores; 25 percent nodules; strongly Average annual air temperature: 47 to 51 effervescent (16 percent calcium carbonate degrees F equivalent); strongly alkaline; clear smooth Frost-free period: 110 to 140 days boundary. Taxonomic class: Fine-silty, mixed, mesic Bk2—34 to 60 inches; light yellowish brown Haploxerollic Durargids (10YR 6/4) silt loam, dark yellowish brown (10YR 4/4) moist; massive; very hard, very Typical Pedon firm, slightly sticky; few very fine and fine A—0 to 4 inches; brown (10YR 5/3) silt loam, roots; common very fine tubular pores; 10 dark brown (10YR 3/3) moist; weak fine percent gravel; strongly effervescent (7 granular structure; slightly hard, friable, percent calcium carbonate equivalent); slightly sticky and slightly plastic; many very strongly alkaline. fine, fine, and medium roots; many very fine Typical Pedon Location and fine tubular pores; neutral; clear smooth boundary. Map unit in which located: Power-Owinza-Rock Bt1—4 to 8 inches; yellowish brown (10YR 5/4) outcrop complex, 1 to 8 percent slopes silt loam, brown (10YR 4/3) moist; moderate Location in survey area: About 12 miles medium subangular blocky structure; slightly northwest of Buhl, Idaho; in the 1 1 1 hard, friable, sticky and plastic; many very SE /4SW /4NW /4 of sec. 4, T. 8 S., R. 18 E. fine, fine, and medium roots; common very Range in Characteristics fine and fine tubular pores; few faint clay films on faces of peds and in pores; neutral; Profile: gradual wavy boundary. Depth to bedrock—more than 60 inches Bt2—8 to 15 inches; pale brown (10YR 6/3) silty Depth to secondary lime—15 to 24 inches clay loam, brown (10YR 4/3) moist; moderate A horizon: medium subangular blocky structure; hard, Value—5 or 6 dry, 3 or 4 moist firm, sticky and plastic; common very fine, Chroma—2 or 3 fine, and medium roots; common very fine, fine, and medium tubular pores; common Bt horizon: distinct clay films on faces of peds Value—5 or 6 dry, 3 or 4 moist and in pores; neutral; clear smooth Chroma—3 or 4 boundary. Texture—silt loam, loam, or silty clay loam Bkq—15 to 26 inches; light gray (10YR 7/2) silt Clay content—24 to 30 percent loam, brown (10YR 5/3) moist; massive; hard, Reaction—mildly alkaline or moderately firm, slightly sticky and slightly plastic; alkaline common very fine, fine, and medium roots; Bk horizon: many very fine and fine tubular pores; 10 Value—6 to 8 dry, 4 to 6 moist percent durinodes; strongly effervescent (21 Chroma—2 to 4 percent calcium carbonate equivalent); mildly Texture—silt loam or loam alkaline; abrupt smooth boundary. Gravel content—0 to 10 percent Bkqm—26 to 51 inches; thin cemented duripan 1 Calcium carbonate equivalent—15 to 30 with /8-inch-thick laminar cap over very pale percent brown (10YR 7/3) loam, brown (10YR 5/3) moist; massive; extremely hard, very firm; Purdam Series root mat on laminar cap and few very fine roots along fracture planes; strongly Depth class: Moderately deep to a duripan effervescent (16 percent calcium carbonate Drainage class: Well drained equivalent); moderately alkaline; clear smooth Permeability: Moderately slow boundary. Position on landscape: Terraces 2Ck—51 to 66 inches; very pale brown (10YR Parent material: Kind—old alluvium; source— 7/3) very fine sandy loam, yellowish brown mixed (10YR 5/6) moist; massive; slightly hard, Slope range: 1 to 30 percent friable; strongly effervescent (15 percent Elevation: 3,000 to 5,000 feet calcium carbonate equivalent); mildly Average annual precipitation: 8 to 11 inches alkaline. Jerome-Twin Falls, Idaho 209

Typical Pedon Location Taxonomic class: Mixed, mesic Xeric Torripsamments Map unit in which located: Purdam silt loam, 1 to 4 percent slopes Typical Pedon Location in survey area: About 12 miles A1—0 to 5 inches; pale brown (10YR 6/3) loamy northwest of Buhl, Idaho; in the 1 1 1 fine sand, brown (10YR 4/3) moist; single NE /4NW /4SE /4 of sec. 12, T. 9 S., grain; loose; many very fine and fine roots R. 12 E. and common medium roots; many pores; strongly effervescent (7 percent calcium Range in Characteristics carbonate equivalent); moderately alkaline; Profile: gradual wavy boundary. Depth to bedrock—more than 60 inches A2—5 to 39 inches; pale brown (10YR 6/3) loamy Depth to secondary lime—8 to 20 inches fine sand, brown (10YR 4/3) moist; single Depth to duripan—20 to 40 inches grain; loose; common very fine and fine roots; many pores; slightly effervescent (7 percent Particle-size control section: calcium carbonate equivalent); moderately Clay content—26 to 32 percent alkaline; gradual wavy boundary. A horizon: A3—39 to 54 inches; pale brown (10YR 6/3) Value—5 or 6 dry, 3 or 4 moist loamy fine sand, brown (10YR 4/3) moist; Chroma—2 or 3 single grain; slightly hard, very friable; common very fine and fine roots; many Bt horizon: pores; slightly effervescent (10 percent Value—5 or 6 dry, 3 or 4 moist calcium carbonate equivalent); moderately Chroma—2 to 4 alkaline; clear smooth boundary. Texture—silt loam or silty clay loam 2Ck—54 to 70 inches; light gray (10YR 7/2) Bkq horizon: stratified silt loam and fine sandy loam, Value—6 to 8 dry, 4 to 6 moist brown (10YR 5/3) moist; moderate medium Chroma—2 to 4 platy structure; hard, friable, slightly sticky Texture—loam or silt loam and slightly plastic; few very fine and fine Rock fragment content—0 to 10 percent roots; few very fine and fine tubular pores; Clay content—12 to 22 percent strongly effervescent (17 percent calcium Calcium carbonate equivalent—15 to 30 carbonate equivalent); moderately alkaline. percent Typical Pedon Location Durinode content—10 to 30 percent Map unit in which located: Quincy loamy fine Bkqm horizon: 1 sand, 2 to 20 percent slopes Thickness of upper silica lamination— /16 to 1 Location in survey area: About 14 miles /2 inch northwest of Buhl, Idaho; in the Texture—very fine sandy loam, loam, or silt 1 1 1 SE /4NE /4NE /4 of sec. 9, T. 8 S., R. 13 E. loam Range in Characteristics Quincy Series Profile: Depth class: Very deep and deep Depth to bedrock—more than 60 inches Drainage class: Excessively drained Depth to secondary lime—more than 39 inches Permeability: Rapid Depth to duripan—40 to 60 inches or more Position on landscape: Terraces A1 and A2 horizons: Parent material: Kind—old alluvium and eolian Chroma—2 or 3 sand; source—mixed Effervescence—none to strong Slope range: 1 to 20 percent Reaction—neutral to moderately alkaline Elevation: 3,000 to 4,000 feet Average annual precipitation: 8 to 10 inches 2Ck horizon: Average annual air temperature: 47 to 49 Chroma—2 or 3 degrees F Texture—fine sandy loam, silt loam, or clay loam Frost-free period: 130 to 140 days Reaction—mildly alkaline or moderately alkaline 210 Soil Survey

Rad Series common very fine tubular pores and few fine tubular pores; 25 percent durinodes; strongly Depth class: Very deep effervescent; moderately alkaline; clear Drainage class: Well drained smooth boundary. Permeability: Slow Bkq2—26 to 32 inches; very pale brown (10YR Position on landscape: Terraces 7/3) silt loam, brown (10YR 5/3) moist; Parent material: Kind—alluvium; source—mixed massive; slightly hard, firm, slightly sticky Slope range: 0 to 20 percent and slightly plastic; few very fine roots; Elevation: 3,200 to 4,500 feet common very fine tubular pores and few fine Average annual precipitation: 8 to 11 inches tubular pores; 20 percent durinodes; strongly Average annual air temperature: 48 to 50 effervescent; moderately alkaline; clear degrees F smooth boundary. Frost-free period: 110 to 140 days Bkq3—32 to 41 inches; very pale brown (10YR 7/3) silt loam, brown (10YR 5/3) moist; Taxonomic class: Coarse-silty, mixed, mesic massive; soft, very friable, slightly sticky and Durixerollic Camborthids slightly plastic; few very fine roots; common Typical Pedon very fine tubular pores and few fine tubular pores; 15 percent durinodes; strongly A1—0 to 2 inches; pale brown (10YR 6/3) silt effervescent; moderately alkaline; gradual loam, very dark grayish brown (10YR 3/2) smooth boundary. moist; weak medium platy structure; soft, Bk—41 to 60 inches; very pale brown (10YR 7/3) very friable, slightly sticky and slightly silt loam, brown (10YR 5/3) moist; massive; plastic; many very fine, fine, and medium soft, very friable, slightly sticky and slightly roots; common very fine and fine tubular plastic; few very fine roots; common very fine pores; mildly alkaline; abrupt smooth tubular pores and few fine tubular pores; boundary. strongly effervescent; strongly alkaline. A2—2 to 6 inches; pale brown (10YR 6/3) silt loam, very dark grayish brown (10YR 3/2) Typical Pedon Location moist; strong fine granular structure; slightly hard, very friable, slightly sticky and slightly Map unit in which located: Rad silt loam, 0 to 2 plastic; many very fine, few fine and many percent slopes medium roots; common very fine and fine Location in survey area: About 1 mile north of 1 1 1 tubular pores; mildly alkaline; abrupt smooth Kimberly, Idaho; in the SW /4SE /4SE /4 of boundary. sec. 16, T. 10 S., R. 18 E. Bw1—6 to 12 inches; pale brown (10YR 6/3) silt loam, brown (10YR 4/3) moist; weak coarse Range in Characteristics subangular blocky structure; hard, friable, Profile: slightly sticky and slightly plastic; many very Depth to bedrock—more than 60 inches fine roots, common fine roots, and few Depth to secondary lime—12 to 28 inches medium roots; common very fine tubular pores and few fine and medium tubular pores; A horizon: moderately alkaline; clear smooth boundary. Value—5 or 6 dry, 3 or 4 moist Bw2—12 to 17 inches; very pale brown (10YR Chroma—2 or 3 7/3) silt loam, brown (10YR 5/3) moist; Bw horizon: moderate medium subangular blocky Value—5 to 7 dry, 4 or 5 moist structure; hard, friable, slightly sticky and Chroma—2 or 3 slightly plastic; many very fine roots, Clay content—6 to 14 percent common fine roots, and few medium roots; common very fine and fine tubular pores and Bkq horizon: few medium tubular pores; moderately Value—6 to 8 dry, 4 to 6 moist alkaline; clear smooth boundary. Chroma—2 or 3 Bkq1—17 to 26 inches; very pale brown (10YR Effervescence—strongly effervescent or violently 7/3) silt loam, brown (10YR 5/3) moist; effervescent massive; hard, firm, slightly sticky and Reaction—moderately alkaline or strongly slightly plastic; common very fine roots; alkaline Jerome-Twin Falls, Idaho 211

Durinode content—10 to 40 percent Typical Pedon Location Map unit in which located: Ragpie-Flatron Ragpie Series complex, 2 to 20 percent slopes Location in survey area: About 8 miles east of Depth class: Shallow to welded tuff 1 1 1 Hollister, Idaho; in the NE /4NE /4SE /4 of sec. Drainage class: Well drained 25, T. 12 S., R. 17 E. Permeability: Moderately slow Position on landscape: Ridges and dip slopes Range in Characteristics Parent material: Kind—residuum; source—welded Profile: tuff Depth to bedrock—10 to 20 inches Slope range: 2 to 20 percent Thickness of mollic epipedon—8 to 13 inches Elevation: 5,000 to 5,700 feet Base saturation—65 to 75 percent Average annual precipitation: 14 to 16 inches Particle-size control section: Average annual air temperature: 45 to 48 Clay content—26 to 34 percent degrees F A horizon: Frost-free period: 100 to 110 days Chroma—2 or 3 Taxonomic class: Loamy-skeletal, mixed, mesic Bt horizon: Lithic Ultic Argixerolls Value—5 or 6 dry, 3 or 4 moist Typical Pedon Chroma—2 or 3 Texture—very gravelly clay loam, gravelly loam, A—0 to 3 inches; brown (10YR 5/3) very very gravelly loam, or gravelly clay loam gravelly loam, very dark grayish brown Gravel content—25 to 40 percent (10YR 3/2) moist; weak fine granular Cobble content—5 to 10 percent structure; soft, friable, slightly sticky and slightly plastic; many very fine to medium roots; many very fine tubular pores; 35 Rakane Series percent gravel, 15 percent cobbles, and 5 Depth class: Moderately deep to a duripan percent stones; neutral; clear smooth Drainage class: Well drained boundary. Permeability: Moderately slow Bt1—3 to 9 inches; brown (10YR 5/3) gravelly Position on landscape: Terraces clay loam, very dark grayish brown (10YR Parent material: Kind—old alluvium; source— 3/2) moist; moderate medium subangular mixed blocky structure; slightly hard, friable, sticky Slope range: 1 to 15 percent and plastic; many very fine to medium roots; Elevation: 3,000 to 4,000 feet many very fine tubular pores; few faint clay Average annual precipitation: 8 to 10 inches films on faces of peds and in pores; 25 Average annual air temperature: 47 to 49 percent gravel and 5 percent cobbles; neutral; degrees F clear smooth boundary. Frost-free period: 120 to 140 days Bt2—9 to 16 inches; pale brown (10YR 6/3) very gravelly clay loam, brown (10YR 4/3) moist; Taxonomic class: Fine-loamy, mixed, mesic moderate medium subangular blocky Xerollic Durargids structure; hard, friable, sticky and plastic; few Typical Pedon very fine and fine roots; common very fine tubular pores; common distinct clay films on A—0 to 3 inches; brown (10YR 5/3) loam, dark faces of peds and in pores; 30 percent brown (10YR 3/3) moist; moderate medium gravel and 10 percent cobbles; slightly platy structure; slightly hard, friable, slightly effervescent in places; neutral; abrupt smooth sticky and slightly plastic; common very fine boundary. roots; many very fine and fine tubular pores; R—16 inches; gray (10YR 6/1) fractured welded 10 percent gravel; slightly acid; clear smooth tuff, dark gray (10YR 4/1) moist; gray (10YR boundary. 6/1) lime pendants on underside of welded BA—3 to 9 inches; pale brown (10YR 6/3) loam, tuff, dark gray (10YR 4/1) moist; pendants brown (10YR 4/3) moist; weak medium 1 1 /8 to /4 inch in diameter. subangular blocky structure; slightly hard, 212 Soil Survey

friable, slightly sticky and slightly plastic; Rogerson Series common very fine roots; many very fine and fine tubular pores; 5 percent gravel; neutral; Depth class: Shallow to a duripan clear smooth boundary. Drainage class: Well drained Bt1—9 to 25 inches; light yellowish brown (10YR Permeability: Slow 6/4) clay loam, brown (10YR 4/3) moist; Position on landscape: Terraces moderate medium subangular block structure; Parent material: Kind—alluvium; source—mixed hard, firm, sticky and plastic; common very Slope range: 2 to 6 percent fine roots; common very fine tubular pores; Elevation: 5,000 to 5,500 feet common distinct clay films on faces of peds Average annual precipitation: 10 to 14 inches and in pores; 10 percent gravel; neutral; Average annual air temperature: 45 to 48 gradual wavy boundary. degrees F Bt2—25 to 38 inches; very pale brown (10YR 7/3) Frost-free period: 100 to 110 days gravelly loam, brown (10YR 5/3) moist; Taxonomic class: Clayey, montmorillonitic, moderate medium subangular blocky mesic, shallow Abruptic Xerollic Durargids structure; very hard, firm, sticky and plastic; few fine medium roots; common fine tubular Typical Pedon pores; common distinct clay films on faces of peds and in pores; 30 percent gravel; mildly E—0 to 4 inches; pale brown (10YR 6/3) silt alkaline; abrupt smooth boundary. loam, dark brown (10YR 3/3) moist; weak fine Bkqm—38 to 73 inches; continuous silica- and granular structure; soft, very friable, slightly calcium-cemented indurated duripan; silica sticky and slightly plastic; many very fine 1 lenses /4 to 1 inch thick every 3 to 4 inches and fine roots; many very fine tubular pores; with extremely hard cemented material neutral; abrupt smooth boundary. between lenses. Bt1—4 to 10 inches; brown (10YR 5/3) silty clay, dark brown (10YR 4/3) moist; moderate Typical Pedon Location medium angular blocky structure; very hard, Map unit in which located: Rakane-Blacknest very firm, very sticky and very plastic; many complex, 1 to 4 percent slopes very fine and fine roots; common very fine Location in survey area: About 14 miles tubular pores; many distinct clay films on northwest of Buhl, Idaho; in the faces of peds and in pores; neutral; abrupt 1 1 1 NE /4NE /4NW /4 of sec. 19, T. 8 S., R. 13 E. smooth boundary. Bt2—10 to 15 inches; pale brown (10YR 6/3) silty Range in Characteristics clay, brown (10YR 4/3) moist; moderate Profile: medium angular blocky structure; hard, firm, Depth to bedrock—more than 60 inches sticky and plastic; common very fine and fine Depth to duripan—20 to 40 inches roots; common very fine tubular pores; few Depth to sand and gravel—30 to 60 inches or faint clay films on faces of peds and in pores; more 5 percent gravel; neutral; clear wavy boundary. Particle-size control section: Bkqm—15 to 21 inches; very pale brown (10YR Rock fragment content—0 to 30 percent 7/3) silty clay loam, brown (10YR 5/3) moist; Clay content—18 to 32 percent massive; very hard, very firm, sticky and A horizon: plastic; 5 percent gravel; many very hard 1 1 Value—5 or 6 dry, 3 or 4 moist durinodes /4 to /2 inch in diameter; weakly Chroma—2 or 3 cemented to moderately cemented very thin Gravel content—0 to 10 percent laminar cap at top; strongly effervescent (21 percent calcium carbonate equivalent); Bt horizon: moderately alkaline; gradual wavy boundary. Value—6 or 7 dry, 3 to 5 moist Bk1—21 to 44 inches; very pale brown (10YR Texture—gravelly loam, loam, sandy clay loam, 7/3) silt loam, brown (10YR 5/3) moist; or clay loam massive; hard, firm, slightly sticky and Bkqm horizon: slightly plastic; few very fine irregular pores; Thickness of duripan—10 to 40 inches or more common fine to medium segregated lime Jerome-Twin Falls, Idaho 213

filaments; strongly effervescent (23 percent Taxonomic class: Loamy, mixed, mesic, shallow calcium carbonate equivalent); moderately Xerollic Durargids alkaline; gradual wavy boundary. Typical Pedon Bk2—44 to 62 inches; very pale brown (10YR 7/3) gravelly sandy loam, brown (10YR 5/3) A—0 to 3 inches; pale brown (10YR 6/3) silt moist; massive; hard, firm, slightly sticky and loam, dark brown (10YR 3/3) moist; slightly plastic; few very fine irregular pores; moderate medium platy structure; slightly 15 percent gravel; strongly effervescent (53 hard, very friable, slightly sticky and percent calcium carbonate equivalent); slightly plastic; many roots; many very fine strongly alkaline. tubular pores; neutral; clear smooth boundary. Typical Pedon Location Bt—3 to 8 inches; pale brown (10YR 6/3) silty Map unit in which located: Schnipper-Rogerson clay loam, brown (10YR 4/3) moist; moderate complex, 2 to 12 percent slopes medium subangular blocky structure; hard, Location in survey area: About 14 miles east of firm, sticky and plastic; many roots; many 1 1 1 Hollister, Idaho; in the NW /4NW /4SW /4 of very fine tubular pores; common faint clay sec. 25, T. 12 S., R. 17 E. films on faces of peds and in pores; mildly alkaline; abrupt smooth boundary. Range in Characteristics Bk—8 to 15 inches; very pale brown (10YR 8/3) Profile: silt loam, pale brown (10YR 6/3) moist; Depth to bedrock—more than 60 inches massive; very hard, firm, slightly sticky and Depth to duripan—10 to 20 inches slightly plastic; common very fine to medium roots; common very fine tubular pores; Particle-size control section: violently effervescent (18 percent calcium Clay content—38 to 55 percent carbonate equivalent); mildly alkaline; abrupt E horizon: smooth boundary. Value—5 or 6 dry, 3 or 4 moist Bkqm—15 to 18 inches; white (10YR 8/1) Chroma—2 or 3 duripan, light gray (10YR 7/2) moist; platy; 1 indurated; two /32-inch-thick lime- and silica- Bt horizon: cemented laminar caps; strongly cemented Value—4 to 6 dry, 3 or 4 moist soil material between laminar caps; violently Chroma—3 or 4 effervescent; moderately alkaline; abrupt Texture—clay, silty clay, or silty clay loam smooth boundary. Gravel content—0 to 10 percent 2Bkq—18 to 27 inches; light yellowish brown Bkqm horizon: (10YR 6/4) sandy loam, yellowish brown 1 1 Thickness of upper silica lamination— /8 to /4 (10YR 5/4) moist; massive; very hard, very inch firm; violently effervescent (25 percent Cementation between laminations—weak to calcium carbonate equivalent); moderately strong alkaline; abrupt smooth boundary. Texture—loam, silty clay loam, or silt loam 2Bkqm—27 to 45 inches; white (10YR 8/1) fractured duripan, light gray (10YR 7/2) moist; Roseworth Series platy; indurated; extremely hard, extremely firm; many 2- to 6-inch-thick lime- and silica- 1 3 Depth class: Shallow to a duripan cemented lenses; fractures /2 to /4 inch wide Drainage class: Well drained and 8 inches apart; below 45 inches the Permeability: Moderately slow duripan is massive and restrictive to Position on landscape: Terraces penetration. Parent material: Kind—alluvium; source—mixed Typical Pedon Location Slope range: 1 to 8 percent Elevation: 4,000 to 4,600 feet Map unit in which located: Roseworth silt loam, 1 Average annual precipitation: 8 to 10 inches to 8 percent slopes Average annual air temperature: 47 to 49 Location in survey area: About 19 miles west of 1 1 1 degrees F Hollister, Idaho; in the NE /4NW /4NW /4 of Frost-free period: 100 to 120 days sec. 21, T. 12 S., R. 13 E. 214 Soil Survey

Range in Characteristics Typical Pedon Profile: A1—0 to 1 inch; light gray (10YR 7/2) loam, Depth to bedrock—more than 60 inches grayish brown (10YR 5/2) moist; few fine faint Depth to secondary lime—6 to 10 inches mottles, dark yellowish brown (10YR 4/6) Depth to duripan—10 to 20 inches moist; moderate medium platy structure; soft, very friable; common very fine, fine, and A horizon: medium roots; many coarse vesicular pores; Value—3 or 4 moist 10 percent gravel; neutral; abrupt smooth Chroma—2 or 3 boundary. Texture—silt loam or cobbly silt loam A2—1 inch to 4 inches; light gray (10YR 7/2) clay Gravel content—0 to 10 percent loam, grayish brown (10YR 5/2) moist; Cobble content—0 to 15 percent common fine faint mottles, dark yellowish Stone content—0 to 5 percent brown (10YR 4/6) moist; strong fine platy Bt horizon: structure; slightly hard, friable, sticky and Chroma—2 or 3 plastic; common very fine, fine, and medium Clay content—24 to 34 percent roots; many coarse vesicular pores; 5 percent gravel; neutral; abrupt wavy boundary. Bk horizon: 2Bw1—4 to 18 inches; light brownish gray (10YR Value—7 or 8 dry, 5 or 6 moist 6/2) clay, brown (10YR 4/3) moist; strong Chroma—2 or 3 moderate angular blocky structure; very hard, Texture—silt loam, silty clay loam, or gravelly very firm, very sticky and very plastic; few loam fine and medium roots; few fine tubular pores; Clay content—14 to 30 percent 5 percent gravel; moderately alkaline; gradual Reaction—mildly alkaline or moderately alkaline wavy boundary. Bkqm horizon: 2Bw2—18 to 30 inches; pale brown (10YR 6/3) 1 1 Thickness of laminar caps— /32 to /8 inch clay, yellowish brown (10YR 5/4) moist; Cementation below laminar caps—moderate to strong medium angular blocky structure; very very strong hard, very firm, very sticky and very plastic; Thickness of duripan—2 to 6 inches few fine and medium roots; few fine tubular pores; 5 percent gravel; moderately alkaline; 2Bkqm horizon: gradual wavy boundary. Thickness of laminar caps—2 to 6 inches 2Ck1—30 to 49 inches; pale brown (10YR 6/3) Structure—massive or platy clay loam, brown (10YR 5/3) moist; strong Cementation below laminar caps—moderate or medium angular blocky structure; very hard, strong 1 3 very firm, very sticky and very plastic; few Width of fractures— /4 to /4 inch fine tubular pores; 5 percent gravel; strongly Distance between fractures—7 to 20 inches effervescent in places; lime in veins and Thickness of duripan—28 to 40 inches or more pockets; moderately alkaline; gradual wavy boundary. Roza Series 2Ck2—49 to 73 inches; very pale brown (10YR 7/3) clay loam, yellowish brown (10YR 5/4) Depth class: Very deep moist; strong medium angular blocky Drainage class: Well drained structure; very hard, very firm, very sticky Permeability: Slow and very plastic; few fine tubular pores; 5 Position on landscape: Playas percent gravel; slightly effervescent; Parent material: Kind—alluvium; source—mixed moderately alkaline. Slope range: 0 to 1 percent Elevation: 4,500 to 4,600 feet Typical Pedon Location Average annual precipitation: 8 to 10 inches Map unit in which located: Roza loam, 0 to 1 Average annual air temperature: 49 to 50 percent slopes degrees F Location in survey area: About 4 miles Frost-free period: 110 to 120 days northwest of Hollister, Idaho; in the 1 1 1 Taxonomic class: Fine, montmorillonitic, mesic NE /4NE /4SE /4 of sec. 12, T. 12 S., Xerertic Camborthids R. 15 E. Jerome-Twin Falls, Idaho 215

Range in Characteristics peds and in pores; 30 percent gravel; neutral; clear smooth boundary. Profile: Bt2—9 to 18 inches; brown (10YR 5/3) extremely Depth to bedrock—more than 60 inches gravelly clay loam, dark grayish brown (10YR Particle-size control section: 4/2) moist; moderate medium subangular Clay content—50 to 60 percent blocky structure; hard, firm, very sticky and Presence of cracks—surface to a depth of 18 very plastic; common medium and coarse inches roots; common very fine and fine tubular pores; common distinct clay films on faces of A1 horizon: peds and in pores; 50 percent gravel and 10 Value—5 to 7 dry, 4 or 5 moist percent cobbles; neutral; clear smooth Chroma—2 or 3 boundary. Gravel content—0 to 10 percent Bt3—18 to 28 inches; brown (10YR 5/3) 2Bw horizon: extremely gravelly clay loam, dark grayish Value—6 or 7 dry, 4 or 5 moist brown (10YR 4/2) moist; moderate medium Chroma—2 to 4 subangular blocky structure; hard, firm, Gravel content—0 to 5 percent sticky and plastic; common medium and coarse roots; few very fine tubular pores; few 2Ck horizon: distinct clay films on faces of peds and in Value—6 or 7 dry, 4 or 5 moist pores; slightly effervescent; 40 percent Chroma—3 or 4 gravel, 15 percent cobbles, and 5 percent Gravel content—0 to 15 percent stones; mildly alkaline; abrupt smooth boundary. Ruclick Series R—28 to 36 inches; fractured welded tuff; calcium carbonate coatings in fractures and pockets. Depth class: Moderately deep to welded tuff Drainage class: Well drained Typical Pedon Location Permeability: Slow Map unit in which located: Ruclick very gravelly Position on landscape: Dip slopes loam, 5 to 30 percent slopes Parent material: Kind—colluvium and residuum; Location in survey area: About 5 miles south of source—welded tuff 1 1 1 Rogerson, Idaho; in the NE /4SW /4SW /4 of Slope range: 5 to 30 percent sec. 31, T. 14 S., R. 16 E. Elevation: 5,100 to 6,000 feet Average annual precipitation: 12 to 14 inches Range in Characteristics Average annual air temperature: 47 to 49 degrees F Profile: Frost-free period: 100 to 110 days Depth to bedrock—20 to 40 inches Taxonomic class: Clayey-skeletal, A horizon: montmorillonitic, mesic Aridic Argixerolls Value—4 or 5 dry Chroma—2 or 3 Typical Pedon Bt2 and Bt3 horizons: A—0 to 3 inches; grayish brown (10YR 5/2) very Value—5 or 6 dry, 3 or 4 moist gravelly loam, very dark grayish brown (10YR Chroma—2 or 3 3/2) moist; moderate medium granular Texture—extremely gravelly clay loam, very structure; slightly hard, very friable, slightly gravelly clay, or extremely cobbly clay sticky and slightly plastic; many roots; many Rock fragment content—35 to 60 percent very fine and fine tubular pores; 55 percent Clay content—35 to 50 percent gravel; slightly acid; clear smooth boundary. Bt1—3 to 9 inches; brown (10YR 5/3) gravelly Rutherford Series clay loam, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky Depth class: Moderately deep to welded tuff structure; slightly hard, friable, sticky and Drainage class: Well drained plastic; many roots; many very fine and fine Permeability: Slow tubular pores; few faint clay films on faces of Position on landscape: Ridges and dip slopes 216 Soil Survey

1 1 1 Parent material: Kind—residuum; source—welded SW /4SW /4NW /4 of sec. 27, T. 16 S., tuff R. 13 E. Slope range: 2 to 20 percent Range in Characteristics Elevation: 6,500 to 7,700 feet Average annual precipitation: 15 to 20 inches Profile: Average annual air temperature: 37 to 43 Depth to bedrock—20 to 40 inches degrees F Thickness of mollic epipedon—20 to 30 inches Frost-free period: 20 to 60 days Particle-size control section: Taxonomic class: Loamy-skeletal, mixed Argic Clay content—24 to 35 percent Pachic Cryoborolls Rock fragment content—50 to 85 percent Typical Pedon A horizon: Value—3 to 5 dry, 2 or 3 moist A—0 to 4 inches; grayish brown (10YR 5/2) Chroma—2 or 3 extremely gravelly loam, very dark grayish brown (10YR 3/2) moist; moderate thick platy Bt horizon: structure; hard, friable, slightly sticky and Chroma—2 to 4 slightly plastic; many roots; many very fine Texture—very gravelly clay loam, extremely tubular pores; 70 percent gravel; moderately gravelly clay loam, or very gravelly loam acid; abrupt smooth boundary. Gravel content—45 to 70 percent Bt1—4 to 10 inches; brown (10YR 4/3) very Cobble content—0 to 15 percent gravelly clay loam, very dark grayish brown Reaction—moderately acid or slightly acid (10YR 3/2) moist; moderate fine angular blocky structure; hard, firm, sticky and Schnipper Series plastic; many roots; many very fine tubular pores; common distinct clay films on faces of Depth class: Moderately deep to a duripan peds and in pores; 50 percent gravel; Drainage class: Well drained moderately acid; gradual wavy boundary. Permeability: Moderately slow Bt2—10 to 19 inches; yellowish brown (10YR 5/4) Position on landscape: Terraces very gravelly clay loam, dark brown (10YR Parent material: Kind—alluvium; source—mixed 3/3) moist; strong fine angular blocky Slope range: 2 to 12 percent structure; hard, firm, sticky and plastic; Elevation: 5,000 to 5,500 feet common fine and medium roots; common Average annual precipitation: 10 to 14 inches very fine tubular pores; common prominent Average annual air temperature: 45 to 48 clay films on faces of peds and in pores; 60 degrees F percent gravel; slightly acid; clear smooth Frost-free period: 100 to 110 days boundary. Taxonomic class: Fine-loamy, mixed, mesic Bt3—19 to 26 inches; brown (10YR 5/3) Aridic Durixerolls extremely gravelly clay loam, dark brown (10YR 3/3) moist; strong very fine angular Typical Pedon blocky structure; very hard, very firm, very sticky and very plastic; few very fine and fine A—0 to 7 inches; brown (10YR 4/3) silt loam, roots; few very fine tubular pores; many dark brown (10YR 3/3) moist; weak fine distinct clay films on faces of peds and in granular structure; slightly hard, friable, pores; 70 percent gravel; slightly acid; abrupt slightly sticky and slightly plastic; many very smooth boundary. fine to medium roots; many very fine tubular R—26 inches; gray (10YR 5/1) welded tuff, dark pores; neutral; abrupt smooth boundary. gray (10YR 4/1) moist. Bt—7 to 15 inches; brown (10YR 5/3) silty clay loam, brown (10YR 4/3) moist; moderate Typical Pedon Location medium subangular blocky structure; hard, Map unit in which located: Rutherford extremely firm, sticky and plastic; many very fine to gravelly loam, 2 to 20 percent slopes medium roots; many very fine tubular pores; Location in survey area: About 22 miles common distinct clay films on faces of peds southwest of Rogerson, Idaho; in the and in pores; common very hard durinodes Jerome-Twin Falls, Idaho 217

1 1 /4 to /2 inch in diameter; mildly alkaline; Bkq horizon: abrupt smooth boundary. Calcium carbonate equivalent—10 to 25 percent Bkq—15 to 30 inches; very pale brown (10YR Bkqm horizon: 7/3) silty clay loam, brown (10YR 5/3) moist; 1 1 Thickness of silica laminations— /8 to /2 inch massive; very hard, firm, sticky and plastic; Thickness of duripan—3 to 12 inches common very fine to medium roots; common very fine tubular pores; many very hard 1 1 Scoon Series durinodes /4 to /2 inch in diameter; violently effervescent (24 percent calcium carbonate Depth class: Shallow to a duripan equivalent); strongly alkaline; abrupt smooth Drainage class: Well drained boundary. Permeability: Moderate Bkqm—30 to 39 inches; very pale brown (10YR Position on landscape: Terraces 7/3) gravelly silt loam, brown (10YR 4/3) Parent material: Kind—old alluvium and eolian moist; massive; extremely hard, firm; 30 material; source—mixed percent gravel; thin laminar cap on top; Slope range: 0 to 4 percent weakly cemented matrix; strongly Elevation: 3,350 to 4,500 feet effervescent (12 percent calcium carbonate Average annual precipitation: 8 to 10 inches equivalent); strongly alkaline; abrupt smooth Average annual air temperature: 49 to 51 boundary. degrees F 2Bk—39 to 66 inches; light yellowish brown Frost-free period: 120 to 140 days (10YR 6/4) gravelly clay loam, dark yellowish brown (10YR 4/4) moist; massive; very hard, Taxonomic class: Loamy, mixed, mesic, shallow firm, sticky and plastic; common very fine Xerollic Durorthids irregular pores; 15 percent gravel; common Typical Pedon fine to medium light gray (10YR 7/2) segregated lime filaments, very pale brown A—0 to 4 inches; light brownish gray (10YR 6/2) (10YR 7/4) moist; violently effervescent (25 fine sandy loam, dark grayish brown (10YR percent calcium carbonate equivalent); 4/2) moist; weak fine granular structure; soft, strongly alkaline. friable; common very fine to medium roots; common fine tubular pores; mildly alkaline; Typical Pedon Location gradual wavy boundary. Bk—4 to 13 inches; light brownish gray (10YR Map unit in which located: Schnipper-Rogerson 6/2) loam, dark grayish brown (10YR 4/2) complex, 2 to 12 percent slopes moist; weak fine subangular blocky structure; Location in survey area: About 8 miles east of 1 1 1 slightly hard, friable; common very fine, fine, Hollister, Idaho; in the NW /4NW /4SW /4 of and medium roots; common fine tubular sec. 25, T. 12 S., R. 17 E. pores; strongly effervescent (23 percent Range in Characteristics calcium carbonate equivalent); mildly alkaline; abrupt smooth boundary. Profile: 2Bkqm—13 to 43 inches; continuous silica- and Depth to bedrock—more than 60 inches calcium-cemented indurated duripan; silica- Depth to secondary lime—9 to 24 inches cemented layers 3 to 4 inches thick; thin Depth to duripan—20 to 40 inches layers of calcium-cemented sandy loam or Thickness of mollic epipedon—7 to 15 inches loam between plates; continuous silica Particle-size control section: cementation at a depth of 33 inches. Clay content—26 to 35 percent Typical Pedon Location A horizon: Map unit in which located: Scoon fine sandy Value—4 or 5 dry, 2 or 3 moist loam, 1 to 4 percent slopes Chroma—2 or 3 Location in survey area: About 20 miles Bt horizon: northwest of Buhl, Idaho; in the 1 1 1 Chroma—2 or 3 NE /4NW /4SE /4 of sec. 33, T. 6 S., Texture—silty clay loam, clay loam, or loam R. 13 E. 218 Soil Survey

Range in Characteristics hard, friable; many very fine, fine, and medium roots; common very fine and fine Profile: tubular pores; 30 percent durinodes; strongly Depth to bedrock—more than 60 inches effervescent (15 percent calcium carbonate Depth to duripan—8 to 20 inches equivalent); mildly alkaline; abrupt smooth Particle-size control section: boundary. Gravel content—0 to 15 percent Bkqm—17 to 18 inches; cemented duripan with Clay content—12 to 18 percent continuous silica- and calcium-carbonate- 1 cemented laminar cap /16 inch thick over A horizon: very pale brown (10YR 7/3) silt loam, brown Chroma—2 or 3 (10YR 5/3) moist; moderate fine platy Bk horizon: structure; very hard, firm and brittle; root mat Value—6 or 7 dry, 4 or 5 moist on surface of laminar cap; few very fine roots Chroma—2 or 3 along fracture planes; strongly effervescent Texture—loam or fine sandy loam (15 percent calcium carbonate equivalent); moderately alkaline; clear smooth boundary. 2Bkqm horizon: 2Bkq—18 to 31 inches; very pale brown (10YR Thickness of duripan—48 inches or more 7/3) silt loam, yellowish brown (10YR 5/4) moist; massive; hard, firm; few very fine and fine roots; few very fine and fine tubular Shabliss Series pores; 30 percent durinodes; strongly effervescent (15 percent calcium carbonate Depth class: Shallow to a duripan equivalent); moderately alkaline; abrupt Drainage class: Well drained smooth boundary. Permeability: Moderate 2Bkqm—31 to 36 inches; strongly cemented Position on landscape: Terraces duripan over very pale brown (10YR 7/3) silt Parent material: Kind—alluvium; source—mixed loam, light yellowish brown (10YR 6/4) moist; Slope range: 1 to 8 percent massive; very hard, very firm and brittle; Elevation: 4,400 to 4,900 feet strongly effervescent (11 percent calcium Average annual precipitation: 8 to 10 inches carbonate equivalent); clear wavy boundary. Average annual air temperature: 47 to 49 2Bk—36 to 49 inches; very pale brown (10YR degrees F 7/4) silt loam, yellowish brown (10YR 5/4) Frost-free period: 110 to 120 days moist; massive; soft, very friable; few very Taxonomic class: Loamy, mixed, mesic, shallow fine and fine tubular pores; strongly Haploxerollic Durorthids effervescent (11 percent calcium carbonate equivalent); moderately alkaline; clear wavy Typical Pedon boundary. A—0 to 5 inches; brown (10YR 5/3) silt loam, 3Bkq—49 to 68 inches; light yellowish brown brown (10YR 4/3) moist; moderate medium (10YR 6/4) silt loam, dark yellowish brown platy structure; soft, friable, slightly sticky (10YR 4/4) moist; massive; very hard, firm; and slightly plastic; many very fine, fine, and few very fine and fine tubular pores; slightly medium roots; many very fine and fine effervescent (3 percent calcium carbonate tubular pores; neutral; clear smooth boundary. equivalent); moderately alkaline. Bw—5 to 10 inches; light yellowish brown (10YR Typical Pedon Location 6/4) silt loam, dark yellowish brown (10YR 4/4) moist; moderate medium subangular Map unit in which located: Shabliss silt loam, 1 to blocky structure; slightly hard, friable, slightly 4 percent slopes sticky and slightly plastic; many very fine, Location in survey area: About 7 miles northwest 1 1 1 fine, and medium roots; common very fine of Hollister, Idaho; in the SW /4SW /4NE /4 of and fine tubular pores; neutral; clear smooth sec. 4, T. 12 S., R. 15 E. boundary. Range in Characteristics Bkq—10 to 17 inches; very pale brown (10YR 7/4) silt loam, brown (10YR 5/3) moist; Profile: moderate fine subangular blocky structure; Depth to bedrock—more than 60 inches Jerome-Twin Falls, Idaho 219

Depth to secondary lime—10 to 15 inches medium subangular blocky structure; soft, Depth to duripan—10 to 20 inches very friable; common very fine and fine roots; common fine tubular pores; mildly alkaline; Particle-size control section: gradual wavy boundary. Clay content—8 to 14 percent Bw2—17 to 29 inches; light yellowish brown A horizon: (10YR 6/4) silt loam, brown (10YR 4/3) moist; Value—5 or 6 dry, 3 or 4 moist moderate medium subangular blocky Chroma—2 or 3 structure; slightly hard, friable; few very fine roots; many very fine tubular pores; mildly Bw horizon: alkaline; abrupt smooth boundary. Value—5 or 6 dry, 4 or 5 moist Bk—29 to 66 inches; pale brown (10YR 6/3) silt Chroma—3 or 4 loam, yellowish brown (10YR 5/4) moist; Bkq horizon: massive; hard, friable; few very fine roots; Value—6 or 7 dry, 4 or 5 moist many vesicular pores; strongly effervescent Chroma—3 or 4 (12 percent calcium carbonate equivalent); Durinode content—10 to 20 percent mildly alkaline. Bkqm horizon: Typical Pedon Location Value—7 or 8 dry, 5 or 6 moist Map unit in which located: Shano silt loam, 1 to 4 Chroma—2 or 3 1 percent slopes Thickness of upper silica lamination— /16 inch to Location in survey area: About 2 miles north of 2 inches 1 1 1 Jerome, Idaho; in the SE /4SE /4SW /4 of sec. 1, T. 8 S., R. 16 E. Shano Series Range in Characteristics Depth class: Very deep Drainage class: Well drained Profile: Permeability: Moderate Depth to secondary lime—16 to 40 inches Position on landscape: Terraces A1 horizon: Parent material: Kind—loess; source—mixed Value—4 to 6 dry, 3 or 4 moist Slope range: 1 to 4 percent Chroma—2 or 3 Elevation: 3,500 to 4,000 feet Average annual precipitation: 8 to 10 inches Bw horizon: Average annual air temperature: 47 to 49 Value—5 or 6 dry, 3 or 4 moist degrees F Chroma—3 or 4 Frost-free period: 130 to 140 days Clay content—5 to 10 percent Taxonomic class: Coarse-silty, mixed, mesic Bk horizon: Xerollic Camborthids Value—6 or 7 dry, 4 to 6 moist Chroma—3 or 4 Typical Pedon Texture—silt loam or very fine sandy loam A1—0 to 5 inches; brown (10YR 4/3) silt loam, dark brown (10YR 3/3) moist; moderate Sidlake Series medium platy structure; slightly hard, friable; many very fine and fine roots; many very fine Depth class: Moderately deep to basalt and fine tubular pores; neutral; abrupt smooth Drainage class: Well drained boundary. Permeability: Moderately slow A2—5 to 10 inches; yellowish brown (10YR 5/4) Position on landscape: Terraces silt loam, brown (10YR 4/3) moist; weak Parent material: Kind—eolian material and medium subangular blocky structure; slightly alluvium; source—mixed hard, friable; many very fine and fine roots; Slope range: 1 to 15 percent many fine tubular pores; neutral; clear smooth Elevation: 3,500 to 4,000 feet boundary. Average annual precipitation: 9 to 11 inches Bw1—10 to 17 inches; yellowish brown (10YR Average annual air temperature: 47 to 49 5/4) silt loam, brown (10YR 4/3) moist; weak degrees F 220 Soil Survey

Frost-free period: 130 to 140 days Bt horizon: Value—4 or 5 dry, 3 or 4 moist Taxonomic class: Fine-loamy, mixed, mesic Chroma—3 or 4 Xerollic Haplargids Texture—sandy clay loam, loam, or clay loam Typical Pedon Gravel content—0 to 10 percent A1—0 to 4 inches; brown (10YR 5/3) loamy fine sand, dark brown (10YR 3/3) moist; Sluka Series moderate medium platy structure; loose; Depth class: Moderately deep to a duripan many very fine and fine roots; many fine Drainage class: Well drained irregular pores; neutral; abrupt smooth Permeability: Moderate boundary. Position on landscape: Terraces A2—4 to 12 inches; yellowish brown (10YR 5/4) Parent material: Kind—old alluvium; source— loamy fine sand, dark yellowish brown (10YR mixed 3/4) moist; weak medium subangular blocky Slope range: 1 to 50 percent structure; hard, friable; many very fine and Elevation: 3,000 to 4,500 feet fine roots; many very fine tubular pores; Average annual precipitation: 8 to 10 inches neutral; abrupt smooth boundary. Average annual air temperature: 49 to 51 Bt1—12 to 20 inches; yellowish brown (10YR 5/4) degrees F sandy clay loam, dark yellowish brown (10YR Frost-free period: 120 to 140 days 4/4) moist; moderate medium subangular blocky structure; very hard, firm, sticky and Taxonomic class: Coarse-silty, mixed, mesic plastic; few very fine and fine roots; common Xerollic Durorthids very fine tubular pores; few faint clay films on Typical Pedon faces of peds and in pores; 5 percent gravel; neutral; gradual wavy boundary. A—0 to 4 inches; pale brown (10YR 6/3) silt Bt2—20 to 32 inches; yellowish brown (10YR 5/4) loam, brown (10YR 4/3) moist; moderate sandy clay loam, dark yellowish brown (10YR medium platy structure; soft, very friable, 4/4) moist; moderate medium angular blocky slightly sticky and slightly plastic; many very structure; very hard, firm, sticky and plastic; fine, fine, and medium roots; many very fine few very fine roots; common very fine tubular and fine tubular pores; slightly effervescent (5 pores; common distinct clay films on faces of percent calcium carbonate equivalent); mildly peds and in pores; 10 percent gravel; mildly alkaline; gradual wavy boundary. alkaline; abrupt smooth boundary. Bkq1—4 to 11 inches; pale brown (10YR 6/3) R—32 inches; fractured basalt; lime coatings on silt loam, brown (10YR 5/3) moist; weak surface and in fractures. medium subangular blocky structure; slightly hard, friable; many very fine, fine, and Typical Pedon Location medium roots; many very fine and fine tubular pores; 20 percent durinodes; strongly Map unit in which located: Harsan-Sidlake-Quincy effervescent (10 percent calcium carbonate complex, 1 to 8 percent slopes equivalent); moderately alkaline; clear smooth Location in survey area: About 7 miles northwest 1 1 1 boundary. of Jerome, Idaho; in the NE /4NE /4SW /4 of Bkq2—11 to 21 inches; very pale brown (10YR sec. 20, T. 7 S., R. 16 E. 7/3) silt loam, pale brown (10YR 6/3) moist; weak medium subangular blocky structure; Range in Characteristics very hard, very firm; common very fine, fine, Profile: and medium roots; common very fine tubular Depth to bedrock—20 to 40 inches pores; 40 percent durinodes; strongly effervescent (16 percent calcium carbonate Particle-size control section: equivalent); moderately alkaline; abrupt Clay content—20 to 30 percent smooth boundary. A1 horizon: Bkqm—21 to 37 inches; cemented duripan that 1 Value—4 or 5 dry, 3 or 4 moist has a continuous /16-inch-thick silica- and Chroma—3 or 4 calcium-carbonate-cemented laminar cap Gravel content—0 to 10 percent over pale brown (10YR 6/3) loam, brown Jerome-Twin Falls, Idaho 221

(10YR 5/3) moist; massive; very hard, very Starbuck Series firm and brittle; root mat on surface of laminar cap; few very fine roots along fracture planes; Depth class: Shallow to basalt strongly effervescent (13 percent calcium Drainage class: Well drained carbonate equivalent); moderately alkaline; Permeability: Moderate abrupt smooth boundary. Position on landscape: Terraces 2Bk—37 to 51 inches; pale brown (10YR 6/3) Parent material: Kind—alluvium; source—mixed very fine sandy loam, brown (10YR 5/3) Slope range: 1 to 4 percent moist; massive; slightly hard, friable; strongly Elevation: 3,500 to 4,000 feet effervescent (13 percent calcium carbonate Average annual precipitation: 9 to 10 inches equivalent); moderately alkaline; abrupt Average annual air temperature: 47 to 49 smooth boundary. degrees F 2Bkqm—51 to 61 inches; indurated duripan that Frost-free period: 130 to 140 days has a continuous silica- and calcium- 1 Taxonomic class: Loamy, mixed, mesic Lithic carbonate-cemented laminar cap /4 inch Xerollic Camborthids thick and is underlain by pale brown (10YR 6/3) loam, brown (10YR 4/3) moist; massive; Typical Pedon very hard, very firm and brittle; strongly A—0 to 5 inches; yellowish brown (10YR 5/4) silt effervescent (11 percent calcium carbonate loam, dark yellowish brown (10YR 3/4) moist; equivalent); moderately alkaline. weak fine granular structure; soft, friable; Typical Pedon Location many very fine and fine roots; many very fine and fine vesicular pores; 5 percent gravel; Map unit in which located: Sluka silt loam, 4 to 8 neutral; clear smooth boundary. percent slopes Bw1—5 to 14 inches; yellowish brown (10YR 5/4) Location in survey area: About 16 miles silt loam, brown (10YR 4/3) moist; moderate northwest of Buhl, Idaho; in the 1 1 1 medium subangular blocky structure; slightly SW /4SW /4SE /4 of sec. 15, T. 8 S., R. 12 E. hard, friable; many very fine and fine roots; many fine tubular pores; 5 percent gravel; Range in Characteristics neutral; gradual wavy boundary. Profile: Bw2—14 to 18 inches; light yellowish brown Depth to bedrock—more than 60 inches (10YR 6/4) silt loam, dark yellowish brown Depth to secondary lime—0 to 12 inches (10YR 4/4) moist; moderate medium Depth to duripan—20 to 40 inches subangular blocky structure; slightly hard, friable; few very fine and fine roots; common Particle-size control section: very fine and fine tubular pores; 10 percent Clay content—12 to 18 percent gravel; neutral; abrupt wavy boundary. A horizon: R—18 inches; fractured basalt; lime coating on Value—5 or 6 dry, 3 or 4 moist surface and in fractures. Chroma—2 or 3 Typical Pedon Location Gravel content—0 to 10 percent Calcium carbonate equivalent—0 to 10 percent Map unit in which located: Barrymore-Starbuck Reaction—neutral or mildly alkaline complex, 1 to 4 percent slopes Location in survey area: About 9 miles north of Bkq horizon: 1 1 1 Jerome, Idaho; in the NW /4SW /4SW /4 of Value—6 to 8 dry, 3 to 6 moist sec. 7, T. 7 S., R.18 E. Chroma—2 or 3 Texture—silt loam or very fine sandy loam Range in Characteristics Calcium carbonate equivalent—10 to 20 percent Profile: Durinode content—10 to 40 percent Depth to bedrock—12 to 20 inches Bkqm horizon: Particle-size control section: Calcium carbonate equivalent—15 to 25 percent 1 Clay content—5 to 15 percent Thickness of silica lamination— /16 inch to 2 inches A horizon: Texture—loam, very fine sandy loam, or silt loam Value—5 or 6 dry, 3 or 4 moist 222 Soil Survey

Chroma—3 or 4 and medium roots; common very fine Gravel content—0 to 5 percent irregular pores; 30 percent gravel and 35 percent cobbles; strongly effervescent (18 Bw horizon: percent calcium carbonate equivalent); Value—5 or 6 dry, 3 to 5 moist moderately alkaline; clear smooth boundary. Chroma—3 or 4 Bk2—29 to 61 inches; very pale brown (10YR Gravel content—0 to 10 percent 7/3) extremely cobbly sandy loam, pale brown (10YR 6/3) moist; single grain; hard, Stricker Series firm; few fine and very fine roots; few very fine irregular pores; 30 percent gravel and 50 Depth class: Very deep percent cobbles; strongly effervescent (30 Drainage class: Well drained percent calcium carbonate equivalent); Permeability: Moderate strongly alkaline. Position on landscape: Breaks Parent material: Kind—colluvium; source—welded Typical Pedon Location tuff Map unit in which located: Stricker-Nawt-Rock Slope range: 15 to 75 percent outcrop association, 30 to 75 percent slopes Elevation: 4,300 to 6,000 feet Location in survey area: About 10 miles east of Average annual precipitation: 12 to 16 inches 1 1 1 Hollister, Idaho; in the NE /4SE /4NW /4 of Average annual air temperature: 46 to 48 sec. 17, T. 12 S., R. 18 E. degrees F Frost-free period: 100 to 110 days Range in Characteristics Taxonomic class: Loamy-skeletal, mixed, mesic Calcic Haploxerolls Profile: Depth to bedrock—more than 60 inches Typical Pedon Depth to secondary lime—18 to 32 inches Thickness of mollic epipedon—10 to 18 inches A—0 to 3 inches; grayish brown (10YR 5/2) very stony loam, very dark grayish brown (10YR A horizon: 3/2) moist; weak fine granular structure; soft, Value—4 or 5 dry, 2 or 3 moist very friable, slightly sticky and slightly Chroma—2 or 3 plastic; many roots; many very fine tubular Gravel content—10 to 20 percent pores; 15 percent gravel, 5 percent cobbles, Cobble content—5 to 20 percent and 20 percent stones; neutral; gradual wavy Stone content—15 to 20 percent boundary. Bw2 horizon: Bw1—3 to 12 inches; brown (10YR 5/3) gravelly Value—5 or 6 dry, 3 or 4 moist loam, very dark grayish brown (10YR 3/2) Chroma—2 to 4 moist; weak medium subangular blocky Texture—extremely cobbly loam, very cobbly structure; soft, friable, slightly sticky and clay loam, or very gravelly silt loam slightly plastic; many roots; many very fine Clay content—18 to 30 percent tubular pores; 25 percent gravel and 5 Gravel content—30 to 40 percent percent cobbles; neutral; clear smooth Cobble content—10 to 40 percent boundary. Bw2—12 to 22 inches; pale brown (10YR 6/3) Bk horizon: extremely cobbly loam, brown (10YR 4/3) Value—6 or 7 dry, 5 or 6 moist moist; moderate medium subangular blocky Chroma—3 or 4 structure; slightly hard, friable, slightly sticky Texture—very cobbly loam, extremely cobbly and slightly plastic; many very fine to loam, or extremely cobbly sandy loam medium roots; many very fine tubular pores; Gravel content—20 to 40 percent 35 percent gravel and 40 percent cobbles; Cobble content—30 to 50 percent neutral; abrupt smooth boundary. Calcium carbonate equivalent—15 to 35 percent Bk1—22 to 29 inches; very pale brown (10YR 7/3) extremely cobbly loam, brown (10YR Suepert Series 5/3) moist; massive; hard, firm, slightly sticky and slightly plastic; common very fine, fine, Depth class: Moderately deep to a duripan Jerome-Twin Falls, Idaho 223

Drainage class: Well drained Range in Characteristics Permeability: Moderate Profile: Position on landscape: Terraces Depth to sand, gravel, cobbles, and stones—34 Parent material: Kind—alluvium; source—mixed to 60 inches or more Slope range: 1 to 15 percent Depth to bedrock—more than 60 inches Elevation: 3,000 to 4,000 feet Depth to duripan—20 to 40 inches Average annual precipitation: 9 to 10 inches Average annual air temperature: 50 to 52 Particle-size control section: degrees F Clay content—15 to 25 percent Frost-free period: 130 to 140 days A horizon: Taxonomic class: Loamy-skeletal, mixed, mesic Value—5 or 6 dry, 3 or 4 moist Xerollic Durorthids Chroma—2 to 4 Gravel content—5 to 20 percent Typical Pedon Cobble content—40 to 45 percent A—0 to 8 inches; yellowish brown (10YR 5/4) Stone content—15 to 20 percent extremely stony silt loam, dark brown (10YR Bw horizon: 3/3) moist; weak fine granular structure; soft, Value—5 or 6 dry, 3 or 4 moist friable, slightly sticky and slightly plastic; Chroma—2 to 4 many very fine and fine roots; common very Texture—very cobbly loam, very cobbly silt loam, fine tubular pores; 5 percent gravel, 40 or extremely cobbly silt loam percent cobbles, and 15 percent stones; Gravel content—10 to 15 percent neutral; gradual wavy boundary. Cobble content—30 to 50 percent Bw1—8 to 18 inches; yellowish brown (10YR 5/4) Stone content—10 to 15 percent very cobbly silt loam, brown (10YR 4/3) moist; weak medium subangular blocky Bkqm horizon: structure; slightly hard, friable, slightly sticky Thickness of duripan—14 to 28 inches and slightly plastic; many very fine and fine roots; few very fine tubular pores; 10 percent Tanner Series gravel, 30 percent cobbles, and 10 percent stones; neutral; gradual wavy boundary. Depth class: Moderately deep to a duripan Bw2—18 to 32 inches; yellowish brown (10YR Drainage class: Well drained 5/4) extremely cobbly silt loam, brown (10YR Permeability: Slow 4/3) moist; weak medium subangular blocky Position on landscape: Terraces structure; hard, friable, slightly sticky and Parent material: Kind—alluvium and residuum; slightly plastic; common very fine and fine source—mixed and basalt roots; few very fine tubular pores; 10 percent Slope range: 1 to 10 percent gravel, 50 percent cobbles, and 10 percent Elevation: 5,200 to 5,900 feet stones; neutral; abrupt smooth boundary. Average annual precipitation: 9 to 13 inches Bkqm—32 to 48 inches; white (10YR 8/2) very Average annual air temperature: 43 to 46 cobbly indurated duripan, very pale brown degrees F (10YR 7/3) moist; massive; extremely hard, Frost-free period: 90 to 110 days extremely firm; continuous fractured laminar 1 1 1 Taxonomic class: Fine, montmorillonitic, frigid opal cap /16 to /8 inch thick; fractures /4 inch Aridic Durixerolls wide and more than 10 inches apart; violently effervescent; gradual wavy boundary. Typical Pedon C—48 to 80 inches; lime-coated sand, gravel, cobbles, and stones. A—0 to 3 inches; brown (10YR 5/3) silt loam, very dark grayish brown (10YR 3/2) moist; Typical Pedon Location moderate medium platy structure; slightly Map unit in which located: Suepert-Taunton hard, friable, slightly sticky and slightly complex, 1 to 15 percent slopes plastic; many roots; many very fine tubular Location in survey area: About 9 miles west of pores; neutral; abrupt smooth boundary. 1 1 1 Eden, Idaho; in the SW /4NE /4SW /4 of sec. AB—3 to 7 inches; grayish brown (10YR 5/2) silty 26, T. 9 S., R. 18 E. clay loam, very dark grayish brown (10YR 224 Soil Survey

3/2) moist; moderate medium subangular A horizon: blocky structure; slightly hard, friable, sticky Value—4 or 5 dry, 2 or 3 moist and plastic; many roots; many very fine Chroma—2 or 3 tubular pores; slightly acid; clear smooth Bt1 horizon: boundary. Chroma—2 or 3 Bt1—7 to 16 inches; brown (10YR 5/3) silty clay Texture—silty clay loam or clay loam loam, dark brown (10YR 3/3) moist; strong Clay content—30 to 38 percent fine angular blocky structure; hard, firm, sticky and plastic; common very fine, fine, Bt2 horizon: and medium roots; common very fine tubular Value—5 or 6 dry, 3 or 4 moist pores; common distinct clay films on faces of Chroma—2 or 3 peds and in pores; neutral; gradual wavy Texture—silty clay, cobbly silty clay, or gravelly boundary. silty clay Bt2—16 to 22 inches; pale brown (10YR 6/3) silty Gravel content—0 to 10 percent clay, brown (10YR 4/3) moist; strong medium Cobble content—0 to 10 percent angular blocky structure; hard, firm, sticky Stone content—0 to 5 percent and plastic; few very fine and fine roots; few Clay content—40 to 48 percent very fine tubular pores; common distinct clay Bk horizon: films on faces of peds and in pores; neutral; Value—6 to 8 dry, 4 to 7 moist gradual wavy boundary. Chroma—3 or 4 Bk—22 to 35 inches; very pale brown (10YR 8/3) Texture—gravelly loam, loam, or silt loam gravelly loam, pale brown (10YR 6/3) moist; Gravel content—5 to 20 percent massive; slightly hard, friable, slightly Cobble content—0 to 5 percent sticky and slightly plastic; few very fine Clay content—16 to 26 percent roots; few very fine tubular pores; 15 percent Reaction—mildly alkaline or moderately gravel and duripan fragments; violently alkaline effervescent (30 percent calcium carbonate equivalent); mildly alkaline; abrupt smooth Bkqm horizon: 1 boundary. Thickness of upper silica lamination— /2 to 1 inch Bkqm—35 to 51 inches; white (10YR 8/2) Thickness of lower silica laminations—1 inch to 2 fractured duripan, very pale brown (10YR 7/3) inches moist; massive; indurated; extremely hard, Thickness of duripan—3 to 16 inches 1 1 extremely firm; many /8- to /2-inch-thick lime- and silica-cemented lenses mixed with Taunton Series 1 basalt gravel and cobbles; fractures /4 inch wide and 12 inches apart; violently Depth class: Moderately deep to a duripan effervescent; moderately alkaline; abrupt Drainage class: Well drained smooth boundary. Permeability: Moderate 2R—51 inches; dark gray (10YR 4/1) basalt, Position on landscape: Terraces black (10YR 2/1) moist; lime coating; Parent material: Kind—alluvium; source—mixed violently effervescent. Slope range: 1 to 8 percent Elevation: 3,000 to 4,100 feet Typical Pedon Location Average annual precipitation: 8 to 10 inches Map unit in which located: Budlewis-Tanner Average annual air temperature: 48 to 52 complex, 2 to 6 percent slopes degrees F Location in survey area: About 20 miles west of Frost-free period: 120 to 140 days 1 1 1 Rogerson, Idaho; in the NW /4NW /4SW /4 of Taxonomic class: Coarse-loamy, mixed, mesic sec. 19, T. 14 S., R. 13 E. Xerollic Durorthids Range in Characteristics Typical Pedon Profile: Ap1—0 to 3 inches; brown (10YR 5/3) sandy Depth to bedrock—40 to 60 inches or more loam, dark brown (10YR 3/3) moist; weak fine Depth to duripan—20 to 40 inches granular structure; loose; many very fine and Thickness of mollic epipedon—8 to 18 inches fine roots; many very fine and fine tubular Jerome-Twin Falls, Idaho 225

pores; slightly effervescent; mildly alkaline; Chroma—2 or 3 clear smooth boundary. Bw horizon: Ap2—3 to 12 inches; brown (10YR 5/3) fine Texture—sandy loam, fine sandy loam, silt loam, sandy loam, brown (10YR 4/3) moist; or loam moderate medium granular structure; slightly hard, friable, slightly sticky; many very fine Bk horizon: and fine roots; many very fine and fine Value—6 to 8 dry, 4 to 6 moist tubular pores; slightly effervescent; mildly Chroma—2 or 3 alkaline; clear smooth boundary. Texture—sandy loam, fine sandy loam, silt loam, Bw—12 to 18 inches; pale brown (10YR 6/3) fine loam, or gravelly loam sandy loam, brown (10YR 4/3) moist; Gravel content—0 to 20 percent moderate medium subangular blocky structure; slightly hard, friable, slightly sticky; Tock Series common very fine and fine roots; common very fine and fine tubular pores; slightly Depth class: Moderately deep to a duripan effervescent; mildly alkaline; clear smooth Drainage class: Well drained boundary. Permeability: Slow Bk1—18 to 29 inches; pale brown (10YR 6/3) fine Position on landscape: Terraces sandy loam, brown (10YR 4/3) moist; Parent material: Kind—alluvium; source—welded moderate medium subangular blocky tuff and volcanic ash structure; slightly hard, friable, slightly sticky; Slope range: 1 to 6 percent few very fine and fine roots; common very Elevation: 5,200 to 5,600 feet fine and fine tubular pores; slightly Average annual precipitation: 12 to 14 inches effervescent; mildly alkaline; clear smooth Average annual air temperature: 43 to 45 boundary. degrees F Bk2—29 to 38 inches; very pale brown (10YR Frost-free period: 90 to 100 days 8/3) gravelly loam, very pale brown (10YR Taxonomic class: Fine, montmorillonitic, frigid 6/3) moist; moderate medium subangular Xerollic Durargids blocky structure; slightly hard, friable, slightly sticky; few very fine roots; few very fine and Typical Pedon fine tubular pores; slightly effervescent; 15 A—0 to 4 inches; pale brown (10YR 6/3) loam, percent gravel-sized duripan fragments; dark brown (10YR 3/3) moist; moderate moderately alkaline; abrupt smooth boundary. medium platy structure; soft, friable, slightly Bkqm—38 to 52 inches; white (10YR 8/2) sticky and slightly plastic; many very fine, fractured indurated duripan, light yellowish fine, and medium roots; many very fine and brown (10YR 6/4) moist; massive; extremely fine tubular pores; neutral; clear smooth hard, extremely firm; many continuous silica- boundary. cemented laminations throughout duripan; Bt1—4 to 13 inches; brown (10YR 5/3) silty clay violently effervescent. loam, dark brown (10YR 3/3) moist; weak fine subangular blocky structure; soft, friable, Typical Pedon Location slightly sticky and slightly plastic; many very Map unit in which located: Taunton sandy loam, 1 fine, fine, and medium roots; common very to 4 percent slopes fine and fine tubular pores; common faint clay Location in survey area: About 4 miles southwest films on faces of peds and in pores; neutral; 1 1 1 of Eden, Idaho; in the NW /4NW /4SW /4 of clear smooth boundary. sec. 31, T. 9 S., R. 19 E. Bt2—13 to 30 inches; yellowish brown (10YR 5/4) silty clay, yellowish brown (10YR 5/4) moist; Range in Characteristics moderate medium angular blocky structure; hard, firm, sticky and plastic; common very Profile: fine, fine, and medium roots; common very Depth to secondary lime—10 to 20 inches fine and fine tubular pores; many distinct clay Depth to duripan—20 to 40 inches films on faces of peds and in pores; 5 Ap1 horizon: percent gravel; neutral; abrupt smooth Value—5 or 6 dry, 3 or 4 moist boundary. 226 Soil Survey

Bkqm—30 to 36 inches; light yellowish brown loam, dark brown (10YR 3/3) moist; moderate (10YR 6/4) indurated duripan, dark yellowish medium platy structure; soft, friable; many brown (10YR 4/4) moist; massive; many very fine and fine roots; many very fine and continuous silica laminations between fine vesicular pores; neutral; clear smooth cemented sand and gravel; abrupt smooth boundary. boundary. Bw—4 to 14 inches; pale brown (10YR 6/3) silt 2C—36 to 60 inches; multicolored loose sand and loam, brown (10YR 4/3) moist; moderate gravel. medium subangular blocky structure; slightly hard, friable; common very fine and fine Typical Pedon Location roots; common very fine and fine tubular Map unit in which located: Tock loam, 1 to 6 pores; neutral; gradual wavy boundary. percent slopes Bkq—14 to 18 inches; light brownish gray (10YR Location in survey area: About 12 miles 6/2) silt loam, dark grayish brown (10YR 4/2) southeast of Rogerson, Idaho; in the moist; moderate medium subangular blocky 1 1 1 NW /4SE /4SW /4 of sec. 7, T. 16 S., R. 17 E. structure; slightly hard, friable; few fine roots; common very fine tubular pores; moderately Range in Characteristics alkaline; abrupt smooth boundary. Profile: R—18 inches; fractured basalt; lime coating on Depth to bedrock—more than 60 inches surface and in fractures. Depth to duripan—20 to 40 inches Typical Pedon Location Particle-size control section: Clay content—35 to 45 percent Map unit in which located: Trevino-Rock outcrop A horizon: complex, 2 to 20 percent slopes Gravel content—0 to 15 percent Location in survey area: About 8 miles east of 1 1 1 Murtaugh, Idaho; in the NE /4SE /4SW /4 of Bt horizon: sec. 28, T. 10 S., R. 21 E. Value—5 or 6 dry, 3 to 5 moist Chroma—3 or 4 Range in Characteristics Texture—silty clay loam or silty clay Profile: Bkqm horizon: 1 Depth to bedrock—10 to 20 inches Thickness of silica laminations— /4 to 1 inch Depth to secondary lime—8 to 18 inches Thickness of duripan—3 to 10 inches Particle-size control section: Trevino Series Clay content—12 to 18 percent A horizon: Depth class: Shallow to basalt Value—5 or 6 dry, 3 or 4 moist Drainage class: Well drained Chroma—2 or 3 Permeability: Moderate Position on landscape: Terraces Bw horizon: Parent material: Kind—alluvium and loess; Value—5 or 6 dry, 3 or 4 moist source—mixed Chroma—2 to 4 Slope range: 0 to 20 percent Texture—silt loam or loam Elevation: 3,000 to 4,500 feet Reaction—neutral or mildly alkaline Average annual precipitation: 8 to 10 inches Bkq horizon: Average annual air temperature: 49 to 51 Value—6 to 8 dry, 4 or 5 moist degrees F Chroma—2 to 4 Frost-free period: 120 to 140 days Texture—silt loam or loam Taxonomic class: Loamy, mixed, mesic Lithic Xerollic Camborthids Tucker Series

Typical Pedon Depth class: Very deep Drainage class: Somewhat poorly drained A—0 to 4 inches; pale brown (10YR 6/3) silt Permeability: Slow Jerome-Twin Falls, Idaho 227

Position on landscape: Flood plains and Range in Characteristics terraces Profile: Parent material: Kind—recent alluvium; source— Depth to bedrock—more than 60 inches welded tuff Depth to mottles—10 to 20 inches Slope range: 0 to 2 percent Depth to water table—18 to 36 inches Elevation: 5,200 to 6,500 feet Thickness of mollic epipedon—25 to 35 inches Average annual precipitation: 12 to 16 inches Average annual air temperature: 43 to 45 Particle-size control section: degrees F Clay content—35 to 50 percent Frost-free period: 80 to 100 days A horizon: Taxonomic class: Fine, montmorillonitic, frigid Value—3 to 5 dry Cumulic Haploxerolls Chroma—1 or 2 Typical Pedon Bw horizon: Hue—2.5YR or 10YR A—0 to 6 inches; dark grayish brown (10YR 4/2) Value—3 to 5 dry, 2 to 4 moist silt loam, black (10YR 2/1) moist; moderate Chroma—1 or 2 fine platy structure; slightly hard, friable, Texture—silty clay loam or silty clay slightly sticky and slightly plastic; many very fine, fine, and medium roots; many very fine Cg horizon: and fine tubular pores; moderately alkaline; Hue—2.5Y or 10YR abrupt smooth boundary. Value—5 or 6 dry, 2 to 4 moist AB—6 to 11 inches; dark grayish brown Chroma—1 to 3 (10YR 4/2) silty clay loam, black (10YR 2/1) moist; weak medium subangular blocky Tulch Series structure; slightly hard, friable, sticky and plastic; many very fine, fine, and medium Depth class: Very deep roots; many very fine and fine tubular Drainage class: Well drained pores; mildly alkaline; clear smooth Permeability: Moderately slow boundary. Position on landscape: Stream terraces Bw—11 to 32 inches; dark grayish brown Parent material: Kind—alluvium; source—mixed (10YR 4/2) silty clay, black (10YR 2/1) moist; Slope range: 0 to 2 percent common faint distinct mottles, dark Elevation: 3,000 to 4,000 feet yellowish brown (10YR 4/4) moist; moderate Average annual precipitation: 8 to 10 inches medium prismatic structure parting to Average annual air temperature: 48 to 50 moderate medium subangular blocky; hard, degrees F firm, sticky and plastic; many very fine, Frost-free period: 120 to 140 days fine, and medium roots; many very fine and Taxonomic class: Fine-silty, mixed, mesic fine tubular pores; neutral; clear smooth Xerollic Camborthids boundary. Cg—32 to 70 inches; gray (10YR 5/1) silty clay, Typical Pedon black (10YR 2/1) moist; common medium faint mottles, very dark grayish brown (10YR A—0 to 3 inches; brown (10YR 5/3) silt loam, 3/2) moist; massive; hard, firm, sticky and dark brown (10YR 3/3) moist; moderate plastic; common very fine and fine roots; medium platy structure; soft, very friable; common very fine and fine tubular pores; common very fine and fine roots; many fine neutral. and very fine tubular pores; neutral; clear smooth boundary. Typical Pedon Location BA—3 to 9 inches; pale brown (10YR 6/3) silt Map unit in which located: Tucker silt loam, 0 to 2 loam, brown (10YR 4/3) moist; weak medium percent slopes subangular blocky structure; soft, very Location in survey area: About 14 miles friable, slightly sticky and slightly plastic; southeast of Rogerson, Idaho; in the common very fine and fine roots; many very 1 1 1 SW /4NW /4NW /4 of sec. 11, T. 16 S., fine and fine tubular pores; mildly alkaline; R. 17 E. gradual wavy boundary. 228 Soil Survey

Bw1—9 to 16 inches; pale brown (10YR 6/3) silt Bk horizon: loam, brown (10YR 4/3) moist; weak medium Value—6 or 7 dry, 4 or 5 moist subangular blocky structure; slightly hard, Texture—very fine sandy loam, silt loam, or silty friable, slightly sticky and slightly plastic; clay loam common fine and very fine roots; common Clay content—16 to 30 percent fine and very fine tubular pores; mildly Durinode content—5 to 20 percent alkaline; clear wavy boundary. Bw2—16 to 34 inches; pale brown (10YR 6/3) Udaho Series silty clay loam, brown (10YR 4/3) moist; moderate medium subangular blocky Depth class: Moderately deep to volcanic ash structure; hard, firm, slightly sticky and Drainage class: Well drained plastic; common very fine and fine roots; Permeability: Moderately rapid common fine tubular pores; 10 percent Position on landscape: Hillsides and breaks durinodes; mildly alkaline; gradual wavy Parent material: Kind—colluvium and residuum; boundary. source—welded tuff and volcanic ash Bw3—34 to 38 inches; very pale brown (10YR Slope range: 10 to 65 percent 7/3) silty clay loam, brown (10YR 5/3) moist; Elevation: 5,000 to 6,000 feet moderate medium subangular blocky Average annual precipitation: 10 to 13 inches structure; hard, firm, sticky and plastic; few Average annual air temperature: 45 to 48 very fine and fine roots; few fine tubular degrees F pores; slightly effervescent (5 percent Frost-free period: 100 to 110 days calcium carbonate equivalent); moderately Taxonomic class: Loamy-skeletal, mixed, mesic alkaline; gradual wavy boundary. Xerollic Calciorthids Bk—38 to 70 inches; very pale brown (10YR 7/3) silty clay loam, brown (10YR 5/3) moist; Typical Pedon massive; very hard, firm, sticky and plastic; A—0 to 7 inches; pale brown (10YR 6/3) very few very fine roots; few fine tubular pores; gravelly loam, dark brown (10YR 4/3) moist; lime in filaments; strongly effervescent (12 weak fine granular structure; slightly hard, percent calcium carbonate equivalent); firm; many very fine, fine, and medium roots moderately alkaline. and common coarse roots; many very fine Typical Pedon Location and fine tubular pores; 35 percent gravel; slightly effervescent; mildly alkaline; gradual Map unit in which located: Tulch silt loam, 0 to 2 wavy boundary. percent slopes Bk1—7 to 14 inches; very pale brown (10YR 7/3) Location in survey area: About 15 miles very gravelly loam, yellowish brown (10YR southeast of Buhl, Idaho; in the 1 1 1 5/4) moist; weak medium subangular blocky NE /4SW /4SE /4 of sec. 14, T. 8 S., structure; slightly hard, firm; many roots; 50 R. 12 E. percent gravel, mostly duripan fragments; Range in Characteristics strongly effervescent (16 percent calcium carbonate equivalent); moderately alkaline; Profile: clear wavy boundary. Depth to bedrock—more than 60 inches Bk2—14 to 31 inches; very pale brown (10YR Depth to secondary lime—26 to 40 inches or 7/3) very gravelly loam, light yellowish brown more (10YR 6/4) moist; massive; slightly hard, firm; Particle-size control section: few coarse roots; 45 percent gravel-sized Clay content—18 to 30 percent duripan and tuff fragments; strongly effervescent (19 percent calcium carbonate A horizon: equivalent); moderately alkaline; clear wavy Value—5 or 6 dry, 3 or 4 moist boundary. Chroma—2 or 3 Cr—31 to 60 inches; very pale brown (10YR 8/3) Bw horizon: partially consolidated volcanic ash, pale Value—5 to 7 dry, 3 or 4 moist yellow (2.5Y 7/4) moist; massive; extremely Chroma—2 or 3 hard, extremely firm; few coarse roots; Texture—silt loam or silty clay loam slightly effervescent. Jerome-Twin Falls, Idaho 229

Typical Pedon Location Taxonomic class: Coarse-silty, mixed, frigid Cumulic Haploxerolls Map unit in which located: Udaho very gravelly loam, 30 to 65 percent slopes Typical Pedon Location in survey area: About 15 miles south of 1 1 1 Rogerson, Idaho; in the SE /4NE /4NE /4 of A1—0 to 3 inches; dark gray (10YR 4/1) silt loam, sec. 32, T. 16 S., R. 16 E. black (10YR 2/1) moist; strong medium granular structure; slightly hard, friable, Range in Characteristics slightly sticky and slightly plastic; common fine and medium roots; common very fine Profile: and fine tubular pores; neutral; clear smooth Depth to secondary lime—6 to 15 inches boundary. Depth to volcanic ash (paralithic contact)—20 to A2—3 to 11 inches; gray (10YR 5/1) silt loam, 40 inches very dark gray (10YR 3/1) moist; strong Particle-size control section: moderate granular structure; hard, friable, Clay content—10 to 20 percent slightly sticky and slightly plastic; common fine and medium roots; common very fine A horizon: and fine tubular pores; neutral; gradual wavy Value—5 or 6 dry, 3 to 5 moist boundary. Chroma—2 or 3 BA—11 to 26 inches; grayish brown (10YR 5/2) Gravel content—35 to 45 percent silt loam, very dark grayish brown Reaction—mildly alkaline or moderately (10YR 3/2) moist; moderate medium alkaline subangular blocky structure; hard, firm, Bk horizon: slightly sticky and slightly plastic; common Value—5 to 8 dry, 3 to 6 moist fine and medium roots; common very fine Chroma—2 to 4 and fine tubular pores; neutral; gradual wavy Texture—very gravelly loam or very gravelly boundary. sandy loam Bg1—26 to 37 inches; light brownish gray Gravel content—35 to 50 percent (10YR 6/2) silt loam, dark gray (10YR 4/1) Cobble content—0 to 10 percent moist; few fine distinct mottles, dark Calcium carbonate equivalent—15 to 30 yellowish brown (10YR 4/6) moist; moderate percent medium subangular blocky structure; hard, Reaction—moderately alkaline or strongly firm, slightly sticky and slightly plastic; alkaline common fine and medium roots; common very fine and fine tubular pores; neutral; clear Cr horizon: smooth boundary. Hue—2.5Y to 10YR Bg2—37 to 46 inches; light brownish gray (10YR Value—7 or 8 dry, 5 to 7 moist 6/2) silt loam, dark gray (10YR 4/1) moist; Chroma—1 to 4 common medium distinct mottles, yellowish Effervescence—slight to strong brown (10YR 4/6) moist; moderate medium subangular blocky structure; hard, firm, Wagonjacket Series slightly sticky and slightly plastic; common fine and medium roots; common very fine Depth class: Very deep and fine tubular pores; neutral; abrupt smooth Drainage class: Somewhat poorly drained boundary. Permeability: Moderate 2Bg3—46 to 61 inches; light gray (10YR 7/2) Position on landscape: Flood plains gravelly sandy loam, grayish brown (10YR Parent material: Kind—recent alluvium; source— 5/2) moist; many coarse distinct mottles, volcanic ash and welded tuff yellowish brown (10YR 4/6) moist; massive; Slope range: 0 to 1 percent slightly hard, friable; few very fine roots; Elevation: 5,600 to 5,800 feet common very fine and fine tubular pores; 25 Average annual precipitation: 14 to 16 inches percent gravel; neutral; abrupt smooth Average annual air temperature: 42 to 45 boundary. degrees F 3C—61 to 70 inches; multicolored layers of sand Frost-free period: 90 to 105 days and gravel; single grain; loose; many coarse 230 Soil Survey

distinct mottles, yellow (10YR 7/8) moist; fine tubular pores; neutral; clear smooth neutral. boundary. Bw2—8 to 12 inches; brown (10YR 5/3) clay Typical Pedon Location loam, brown (10YR 5/3) moist; moderate Map unit in which located: Wagonjacket silt loam, medium subangular blocky structure; hard, 0 to 1 percent slopes firm, slightly sticky and slightly plastic; few Location in survey area: About 10 miles roots; 80 percent weakly consolidated ash 1 southeast of Rogerson, Idaho; in the fragments that are /4 inch to 4 inches in 1 1 1 SW /4NE /4NE /4 of sec. 23, T. 15 S., R. 17 E. diameter and are oriented in same direction as parent material; neutral; clear wavy Range in Characteristics boundary. Profile: Cr—12 to 60 inches; white (10YR 8/2) weakly Depth to bedrock—more than 60 inches consolidated ash, light gray (10YR 7/2) moist; Depth to mottles—14 to 26 inches strong very coarse platy structure; plates dip Depth to water table—18 to 30 inches down at a 5 percent slope; root mat between plates; top of plates strongly effervescent; A horizon: matrix of plates noncalcareous. Value—4 or 5 dry, 2 or 3 moist Chroma—1 or 2 Typical Pedon Location Bg horizon: Map unit in which located: Weash gravelly sandy Value—5 to 7 dry, 3 to 5 moist loam, 2 to 12 percent slopes Chroma—1 or 2 Location in survey area: About 13 miles south of 1 1 1 Rogerson, Idaho; in the SW /4SE /4NW /4 of Weash Series sec. 13, T. 16 S., R. 15 E. Depth class: Shallow to weakly consolidated ash Range in Characteristics Drainage class: Well drained Profile: Permeability: Moderately slow Depth to weakly consolidated ash—10 to 20 Position on landscape: Terraces inches Parent material: Kind—residuum and eolian material; source—weakly consolidated ash A horizon: Slope range: 2 to 12 percent Value—5 or 6 dry, 3 or 4 moist Elevation: 5,400 to 5,700 feet Chroma—2 to 4 Average annual precipitation: 10 to 12 inches Gravel content—15 to 30 percent Average annual air temperature: 45 to 48 Reaction—neutral or mildly alkaline degrees F Bw horizon: Frost-free period: 100 to 110 days Value—5 to 7 dry, 3 to 5 moist Taxonomic class: Ashy, mesic, shallow Chroma—2 to 4 Vitrixerandic Camborthids Texture—sandy clay loam, clay loam, or loam Clay content—20 to 30 percent Typical Pedon Reaction—neutral to moderately alkaline A—0 to 2 inches; pale brown (10YR 6/3) gravelly sandy loam, dark brown (10YR 4/3) moist; Windypoint Series strong coarse platy structure; slightly hard, friable; many very fine, fine, and medium Depth class: Very deep roots and common coarse roots; many very Drainage class: Well drained fine and fine vesicular pores; 20 percent Permeability: Moderately slow over very rapid gravel; neutral; abrupt smooth boundary. Position on landscape: Terraces Bw1—2 to 8 inches; brown (10YR 5/3) sandy clay Parent material: Kind—alluvium; source—mixed loam, dark brown (10YR 4/3) moist; moderate Slope range: 1 to 4 percent medium subangular blocky structure; hard, Elevation: 4,400 to 4,700 feet firm, slightly sticky and slightly plastic; many Average annual precipitation: 8 to 10 inches very fine, fine, and medium roots and Average annual air temperature: 47 to 49 common coarse roots; many very fine and degrees F Jerome-Twin Falls, Idaho 231

Frost-free period: 110 to 120 days Range in Characteristics Taxonomic class: Fine-loamy, mixed, mesic Profile: Xerollic Haplargids Depth to bedrock—more than 60 inches Depth to sand and gravel—20 to 40 inches Typical Pedon Depth to carbonates—12 to 18 inches A—0 to 3 inches; pale brown (10YR 6/3) loam, A horizon: dark brown (10YR 3/3) moist; moderate fine Value—5 or 6 dry, 3 or 4 moist platy structure; slightly hard, friable; many Chroma—2 or 3 very fine roots; common very fine vesicular pores; 10 percent gravel; neutral; abrupt Bt horizon: smooth boundary. Value—5 or 6 dry Bt1—3 to 9 inches; pale brown (10YR 6/3) Clay content—25 to 30 percent gravelly loam, brown (10YR 4/3) moist; moderate medium subangular blocky Xerorthents structure; hard, firm, sticky and plastic; common fine and medium roots; common Depth class: Shallow to very deep to bedrock fine tubular pores; few faint clay films on Drainage class: Well drained or somewhat faces of peds and in pores; 15 percent excessively drained gravel; mildly alkaline; clear smooth Permeability: Moderately slow to moderately boundary. rapid Bt2—9 to 15 inches; pale brown (10YR 6/3) Position on landscape: Breaks gravelly loam, brown (10YR 4/3) moist; Parent material: Kind—colluvium; source—mixed moderate medium subangular blocky Slope range: 40 to 75 percent structure; hard, firm, sticky and plastic; Elevation: 2,800 to 6,000 feet common fine and medium roots; common Average annual precipitation: 8 to 15 inches fine tubular pores; few faint clay films on Average annual air temperature: 44 to 52 faces of peds and in pores; 15 percent degrees F gravel; mildly alkaline; clear smooth Frost-free period: 90 to 140 days boundary. Taxonomic class: Xerorthents Bt3—15 to 28 inches; pale brown (10YR 6/3) gravelly loam, brown (10YR 4/3) moist; Example Pedon moderate medium subangular blocky A—0 to 6 inches; pale brown (10YR 6/3) stony structure; hard, firm, slightly sticky and loam, dark brown (10YR 3/3) moist; weak fine slightly plastic; common fine and medium granular structure; slightly hard, friable, roots; common fine tubular pores; few faint slightly sticky and slightly plastic; many very clay films on faces of peds and in pores; 25 fine and fine roots; many very fine tubular percent gravel; slightly effervescent; mildly pores; 5 percent gravel, 5 percent cobbles, alkaline; clear smooth boundary. and 10 percent stones; neutral; clear wavy 2Bk—28 to 34 inches; light gray (10YR 7/2) boundary. extremely gravelly sandy loam, grayish C—6 to 60 inches; very pale brown (10YR 7/3) brown (10YR 5/2) moist; massive; slightly loam, brown (10YR 5/3) moist; massive; hard, friable; few fine roots; few fine tubular slightly hard, friable, slightly sticky and pores; 75 percent gravel; strongly slightly plastic; common very fine and fine effervescent; moderately alkaline; gradual roots; common very fine tubular pores; 5 wavy boundary. percent gravel and 5 percent cobbles; mildly 2C—34 to 65 inches; multicolored sand and alkaline. gravel; single grain; loose. Typical Pedon Location Example Pedon Location Map unit in which located: Windypoint-Arbidge Map unit in which located: Rock outcrop- complex, 1 to 4 percent slopes Xerorthents complex, very steep Location in survey area: About 4 miles northwest Location in survey area: About 4 miles northwest 1 1 1 1 1 1 of Hollister, Idaho; in the SE /4SW /4SW /4 of of Castleford, Idaho; in the NE /4NE /4NE /4 of sec. 13, T. 12 S., R. 15 E. sec. 29, T. 10 S., R. 13 E. 232 Soil Survey

Range in Characteristics Bkq—9 to 14 inches; very pale brown (10YR 7/3) silt loam, brown (10YR 5/3) moist; weak Profile: medium subangular block structure; hard, Depth to bedrock—10 to 60 inches or more friable, sticky and plastic; few very fine and Particle-size control section: fine roots; few very fine and fine tubular Clay content—10 to 32 percent pores; 15 percent durinodes; violently effervescent (30 percent calcium carbonate A horizon: equivalent); moderately alkaline; abrupt Value—4 to 6 dry, 2 to 4 moist smooth boundary. Chroma—1 to 3 2Bkqm—14 to 34 inches; indurated duripan with Texture—loamy sand to silt loam continuous silica- and calcium-cemented 1 C horizon: laminar cap /8 inch thick over imbedded Value—6 or 7 dry, 4 to 6 moist lamellae of silica pan and very pale brown Chroma—2 or 3 (10YR 7/3) very fine sandy loam, brown Texture—sandy loam to clay loam (10YR 5/3) moist; very hard, very firm and Gravel content—5 to 30 percent brittle (pans about 5 percent of mass); root Cobble content—5 to 15 percent mat on surface of laminar; few very fine roots Stone content—0 to 5 percent along fracture planes; violently effervescent (14 percent calcium carbonate equivalent); Yahoo Series moderately alkaline; abrupt smooth boundary. 1 3Bkqm—34 to 60 inches; fractured duripan; /4- to Depth class: Shallow to a duripan 2-inch-thick silica lenses throughout Drainage class: Well drained extremely hard, platy, rocklike material. Permeability: Moderate Typical Pedon Location Position on landscape: Terraces Parent material: Kind—old alluvium; source— Map unit in which located: Yahoo silt loam, 1 to 4 mixed percent slopes Slope range: 0 to 4 percent Location in survey area: About 9 miles west of 1 1 1 Elevation: 3,400 to 4,300 feet Buhl, Idaho; in the NE /4NE /4NW /4 of sec. Average annual precipitation: 8 to 10 inches 28, T. 9 S., R. 13E. Average annual air temperature: 47 to 49 degrees F Range in Characteristics Frost-free period: 120 to 140 days Profile: Taxonomic class: Loamy, mixed, mesic shallow Depth to bedrock—more than 60 inches Xerollic Durorthids Depth to carbonates—0 to 4 inches Depth to duripan—12 to 20 inches Typical Pedon Particle-size control section: A—0 to 3 inches; pale brown (10YR 6/3) silt Clay content—20 to 30 percent loam, brown (10YR 4/3) moist; moderate medium platy structure; soft, friable, slightly A horizon: sticky and slightly plastic; many very fine Value—5 or 6 dry, 3 or 4 moist and fine roots and few medium roots; many Calcium carbonate equivalent—0 to 15 percent very fine and fine tubular pores; strongly Reaction—neutral or mildly alkaline effervescent (12 percent calcium carbonate Bkq horizon: equivalent); mildly alkaline; clear smooth Value—5 to 7 dry, 3 to 5 moist boundary. Clay content—18 to 32 percent Bk—3 to 9 inches; brown (10YR 5/3) silt loam, Calcium carbonate equivalent—15 to 30 percent dark brown (10YR 3/3) moist; moderate Durinode content—5 to 20 percent medium subangular blocky structure; slightly hard, friable, sticky and plastic; common very 2Bkqm horizon: fine and fine roots; few very fine and fine Texture—very fine sandy loam, loam, or silt loam tubular pores; slightly effervescent (15 Calcium carbonate equivalent—10 to 30 percent 1 1 percent calcium carbonate equivalent); Thickness of upper silica lamination— /16 to /4 moderately alkaline; abrupt smooth boundary. inch Jerome-Twin Falls, Idaho 233

Zola Series firm, sticky and plastic; few very fine and fine roots; few very fine and fine tubular pores; Depth class: Very deep slightly effervescent (9 percent calcium Drainage class: Moderately well drained carbonate equivalent); few fine irregular soft Permeability: Slow masses of lime; moderately alkaline; abrupt Position on landscape: Flood plains and terraces smooth boundary. Parent material: Kind—recent alluvium; source— 2Bk3—39 to 54 inches; very dark grayish brown welded tuff and volcanic ash (10YR 3/2) clay, very dark gray (10YR 3/1) Slope range: 0 to 2 percent moist; massive; very hard, very firm, very Elevation: 5,200 to 5,800 feet sticky and very plastic; few very fine roots; Average annual precipitation: 12 to 16 inches few fine tubular pores; slightly effervescent (7 Average annual air temperature: 41 to 45 percent calcium carbonate equivalent); few degrees F fine irregular soft masses of lime; moderately Frost-free period: 80 to 100 days alkaline; abrupt smooth boundary. 2Bk4—54 to 70 inches; light yellowish brown Taxonomic class: Fine-loamy, mixed, frigid (2.5Y 6/4) gravelly sandy clay, grayish brown Cumulic Haploxerolls (2.5Y 5/2) moist; common fine faint mottles Typical Pedon (7.5YR 4/6) moist; massive; very hard, very firm, very sticky and very plastic; few fine A—0 to 5 inches; grayish brown (10YR 5/2) pores; slightly effervescent (6 percent loam, black (10YR 2/1) moist; moderate calcium carbonate equivalent); few fine medium platy structure; slightly hard, friable, irregular soft masses of lime; 30 percent slightly sticky and slightly plastic; many gravel; neutral. very fine and fine roots; many very fine and fine tubular pores; neutral; clear smooth Typical Pedon Location boundary. Map unit in which located: Zola loam, 0 to 2 Bw1—5 to 13 inches; dark grayish brown (10YR percent slopes 4/2) loam, very dark grayish brown (10YR Location in survey area: About 18 miles 3/2) moist; moderate medium subangular southeast of Rogerson, Idaho; in the blocky structure; slightly hard, friable, slightly 1 1 1 SE /4NW /4NE /4 of sec. 36, T. 16 S., sticky and slightly plastic; many very fine R. 17 E. and fine roots; many very fine and fine tubular pores; neutral; clear smooth boundary. Range in Characteristics Bw2—13 to 21 inches; brown (10YR 5/3) loam, Profile: very dark grayish brown (10YR 3/2) moist; Depth to bedrock—more than 60 inches moderate medium subangular blocky Depth to mottles—36 to 54 inches structure; slightly hard, friable, slightly sticky Depth to water table—48 to 72 inches and slightly plastic; common very fine and Thickness of mollic epipedon—24 to 54 fine roots; common very fine and fine tubular inches pores; slightly effervescent (12 percent calcium carbonate equivalent); moderately A horizon: alkaline; abrupt smooth boundary. Value—4 or 5 dry, 2 or 3 moist Bk1—21 to 28 inches; grayish brown (10YR 5/2) Chroma—1 to 3 clay loam, very dark grayish brown (10YR Bw horizon: 3/2) moist; moderate medium subangular Value—4 or 5 dry blocky structure; hard, firm, sticky and Chroma—1 to 3 plastic; few very fine and fine roots; few very Texture—loam, silty clay loam, or clay fine and fine tubular pores; strongly loam effervescent (12 percent calcium carbonate Clay content—16 to 30 percent equivalent); common medium irregular filaments or threads of lime; moderately Bk horizon: alkaline; clear smooth boundary. Value—3 to 6 dry Bk2—28 to 39 inches; gray (10YR 5/1) clay loam, Chroma—1 to 4 very dark gray (10YR 3/1) moist; moderate Gravel content—0 to 5 percent medium subangular blocky structure; hard, Effervescence—slight to strong

235

Formation of the Soils

Prepared by Dal Ames, soil scientist, Natural Resources The present climate in the survey area is warm Conservation Service. and dry in summer and generally cool and moist in winter. About 80 percent of the average annual This section describes the major processes precipitation falls during October through May. of soil formation affecting the soils in the survey Much of the precipitation falls as snow at the area. Soil is a natural, three-dimensional body higher elevations. covering the land surface that supports or is Temperature and precipitation are strongly capable of supporting plants (4). It is a influenced by the topography of the area. fundamental part of the ecosystem and exists Generally, average annual precipitation in balance with the other components of the increases and average annual temperature environment. Soil is a mixture of minerals, decreases as elevation increases. The warmest organic matter, water, and air, all of which occur and driest part of the survey area is at the lowest in varying proportions. Soils differ in their elevations along the Snake River. These areas appearance, productivity, and management receive about 10 inches of precipitation annually requirements in different areas and even within and have an average annual temperature of short distances. about 48 degrees F. The greatest amount of Soils are characterized by the vertical precipitation and the coldest temperatures occur sequence of layers, or horizons, that vary in in the mountains in the southwestern part of the color, texture, chemistry, and structure. Horizons survey area. These areas receive about 20 to 25 are continually forming and evolving, usually over inches of precipitation annually and have an long periods of time, in response to average annual temperature of 40 to 44 degrees environmental forces. F. The characteristics and properties of soils are Some of the older soils in the survey area determined by physical and chemical processes developed under different climatic conditions. that result from the interaction of five factors- These soils have an argillic horizon and a high climate, living organisms, topography, time, and accumulation of illuvial clay. They probably parent material (4). The influence of any one of developed dominantly during the Pleistocene these factors varies from place to place, but the (10,000 to 50,000 years ago) when the average interaction of all the factors determines the kind annual precipitation was much greater. of soil that forms. Soil temperatures in the survey area are This section provides information on the widely varied because of the variations in influence of each soil-forming factor on the soils elevation. Relief over the entire area is about in this survey area. 5,000 feet. Mesic soil temperature regimes are at elevations of less than 5,300 to 5,700 feet. Frigid Climate soils generally are at elevations of more than 5,700 feet, but some soils on north and east Climate has had a strong influence on soil aspects at an elevation of about 4,800 feet also formation in the survey area. Temperature and are frigid. Cryic soils are at elevations of more precipitation affect the weathering of rock; the than 6,500 feet. decomposition of minerals; the activity of micro- Precipitation in the area also varies greatly, organisms; the process of leaching, illuviation, depending primarily on elevation. The average and eluviation; the kind and amount of annual precipitation ranges from about 10 inches vegetation; and the accumulation and at Jerome to about 25 inches on the highest decomposition of organic matter. ridges in the southwestern part of the survey 236 Soil Survey

area. Precipitation on the Snake River Plain Topography ranges from less than 9 inches to about 12 inches annually, and most of the soils on the The survey area is characterized by terraces, plain have an aridic soil moisture regime. Soils dip slopes, hill slopes, breaks, ridges, and that are shallow and moderately deep to a summits. These surfaces formed as a result of duripan are common in areas of the Snake River geologic action. Relief influences soil formation Plain where the average precipitation is about by its effect on erosion, effective precipitation, 0.8 inch during July through September. The low soil drainage, air drainage, and exposure to sun precipitation allows the soil profile to dry out and and wind (4). the calcium carbonate and silica to precipitate. Soils on stable terraces generally exhibit the The soil moisture regime is dominantly xeric most development because of the reduced risk at the higher elevations where the precipitation is of erosion and runoff. On steep slopes, parent more than about 13 inches annually. Somewhat material is unstable and the risk of runoff and poorly drained soils on stream bottoms are in erosion is higher. the aquic moisture regime. Soils that have a Aspect dictates the amount of sunlight and duripan and are at elevations of more than 5,800 moisture a soil receives. Soils on north and east feet generally are cemented with silica and do aspects of breaks, hill slopes, and dip slopes not have calcium carbonates in the profile. receive less sunlight than those on south and Oshone and Forvic soils exhibit these west aspects. As a result, the soil temperatures characteristics. are lower and the snow stays on the ground longer, providing moisture longer into the growing Living Organisms season. The moisture is sufficient to produce a thick plant cover that controls erosion; Living organisms, consisting of plant and consequently, the soils are deeper. Because the animal life, play a significant part in soil vegetation is abundant and the soil temperature formation. The kind and amount of vegetation inhibits the breakdown of organic matter, the have a strong influence on soil development. soils in these areas have a thick dark-colored Animals, insects, bacteria, and other organisms surface horizon. Dehana and Doodlelink soils are also influence soil development by adding examples. organic matter to the soil and by stirring and Soils on south and west aspects of breaks, hill aerating it. The kind and amount of living slopes, and dip slopes typically are shallower organisms in an area are largely dependent on and have a thin dark-colored surface layer. The climatic factors. direct sunlight in these areas heats and dries out At elevations below 5,000 feet, plant the soils quickly during the growing season. This production is limited by the amount of effective speeds the breakdown of organic matter and moisture. Annual additions of organic matter are limits plant growth, which increases the risk of small. Relatively young soils, such as those of erosion. Examples are the Stricker and Udaho the Bahem, Portneuf, and Sluka series, have a soils. light-colored surface layer. Older soils in these Soils on ridges and summits are subject to areas, such as those of the Chuska, Power, geologic erosion, and they receive less moisture Purdam, and Roseworth series, have because the snow is blown away by the wind. accumulated more organic matter and have a Generally, these soils dry out quickly because of thin dark-colored surface layer. the warm soil temperatures and the low amount Plant production, especially that of grasses, is of effective moisture. The soils generally are much greater at the higher elevations. The shallow or moderately deep, have a thin surface abundance of fibrous roots adds mulch to the layer, and have a high content of rock fragments. soils, and thick dark-colored surface horizons Brose, Ragpie, and Rutherford soils exhibit these form. Micro-organisms and earthworms are very characteristics. active in these areas. They have influenced the Soils in concave areas and on back slopes color, structure, and physical condition of soils and foot slopes generally receive more moisture such as those of the Doodlelink, Keman, as a result of runoff and snow drifting from Oshone, and Tanner series. convex areas. Because these soils receive more Jerome-Twin Falls, Idaho 237

moisture, they produce more abundant down, elongated gravel bars were deposited. The vegetation, which reduces the risk of erosion. skeletal Suepert soils formed in these deposits. The very deep Congle soils are in concave areas They have a cambic horizon over a weakly and on foot slopes. These soils have a thick developed duripan. dark-colored surface layer. The Bonneville Flood scoured the canyon in Soils on alluvial terraces are nearly level and the existing Snake River channel. Perpendicular have a fluctuating water table. They are cliffs are common in the narrow canyon. The somewhat poorly drained or poorly drained. flood channels joined in the area between the Hutton and Tucker soils are examples. Blue Lakes and one mile below the Hansen Bridge. The waters formed several alcoves, Time widened the canyon, filled the Snake River Canyon, and swept up large chunks of basalt. The climatic factors and the variability of the These rounded boulders, known as Melon parent material, relief, and vegetation in the Gravel, were deposited as sandy gravel bars in survey area have produced a wide variety of many areas along the canyon (8). Soils in the soils; however, the different horizons present in Fathom series formed in these deposits. the soils and the degree of development is North of Buhl, Idaho, the basalt flows directly related to time (4). The relationship protecting the Snake River Canyon give way to between age and soil development is explained lower Pleistocene deposits and middle further in the section “Parent Material.” Pleistocene lava-dammed Snake Plain lakebeds of silt, clay, and diatomite. These deposits make Parent Material up various formations, including the Glens Ferry and Bruneau Formations. Geologically, the survey area is part of the The Glens Ferry Formation is exposed at the Snake River Plain. During the Mesozoic era, the Hagerman Fossil Beds. It is about 2,000 feet area uplifted and low hills formed. Events of the thick and consists of intertonguing lake and Cenozoic era dictated the present geology. stream deposits. Lacustrine material with thick Faults and fissures released molten lava from ripple-marked sand and silt is widespread (8). low profile shield volcanoes. There are about 40 Soils of the Quincy series formed in this material. shield volcanoes and basalt vents in the survey The Bruneau Formation consists of lacustrine area. The bedrock in the area consists of shallow sediment and basalt flows associated with the basalt lava flows underlain by ryholite. These damming and breaching of the Snake River. lava flows intermittently blocked watercourses These extensive areas of silt, clay, and basalt and created pluvial lakes that filled with flows eroded into badlands. Soils of the Kudlac sediment. The basalt flows and volcanic material series formed in this material. along with glacial debris and lacustrine deposits The soils on narrow stream terraces and flood influenced the many soils that developed in the plains formed in recent alluvium (less than survey area (1). 10,000 years old) (16). This alluvium was deposited during periods of stream aggradation. Recent and Pleistocene Deposits These soils developed a thick dark-colored The Bonneville Flood, which occurred less surface layer that supports grass. Subsequent than 14,200 years ago, influenced soil stream degradation has determined the present development in the survey area (1). The soil drainage. The moderately well drained floodwater split into two channels near Milner, Gosinta and Zola soils, the somewhat poorly Idaho. Part of the overflow took a route along an drained Wagonjacket soils, and the poorly upland channel, and the other part followed the drained Hutton soils are examples. Soil texture existing Snake River channel. ranges from silt loam to silty clay, depending on Soils in the upland channel formed an argillic the source of the alluvium. horizon. The shallow Banbury soils formed on During the upper Pleistocene, watercourses upland terraces, and the very deep Paulville soil were dammed by lava flows from basalt vents formed in the intervening troughs and lower lying and shield volcanoes and alluvium accumulated terraces. In areas where the waterflow slowed in the uplands (1). In the western part of Jerome 238 Soil Survey

County, sandy alluvial material from ancient Lake formed in fine-loamy material from which calcium McKinney accumulated. Soils that formed in carbonate was leached. The McCain and Power these areas include the Kecko soils that have a soils formed in fine-silty material. These soils cambic horizon, the Harsan and Hoosegow soils have a layer of calcium carbonate accumulation that have an argillic horizon, and the Taunton and an argillic horizon. The Idow soils formed on soils that have a nonconforming duripan. The broad terraces between pressure ridges. These Quincy soils formed in areas where sandy soils have a duripan. The fine-textured Owinza alluvium was reworked. soils formed in areas where clay and salts Lava flowed from shield volcanoes, such as accumulated in depressions between terraces Flat Top, Hansen, Hazelton, Hub, Skeleton, and pressure ridges. Soils that formed on the Sonnicksen, and Stricker Buttes, from the lower younger basalt flows, such as those of the to upper Pleistocene. Using the carbon-14 Barrymore and Starbuck series, developed a method, the age of a paleosol under the Stricker cambic horizon. Butte lava flow was estimated at 14,200+ 210 Soils on upland terraces in the south-central years B.P. Thus, the maximum age for the basalt, part of Twin Falls County (about 4,000 to 5,600 the lacustrine silt geomorphic surfaces, and the feet in elevation) developed in a mixture of loess soils is less than 14,200 years. The truncated and alluvium (16). Lower to middle Pleistocene duripans are more than 14,200 years old, and basalt underlies these areas (11). Most of the the durinodes are less than 14,200 years old (7). soils have a layer of calcium carbonate The silty soils that formed in the pluvial lakes accumulation and are shallow to a well have an accumulation of calcium carbonate. developed, thick duripan that may be a remnant Some of these soils, such as those of the Trevino of an eroded paleosol. The Chiara soils formed in series, are shallow to basalt, and some are mixed coarse-silty alluvium and loess; the underlain by a duripan, such as those of the Chuska, Colthorp, Elijah, Lankbush, and Minidoka and Minveno series. A large area of Roseworth soils formed in moderately fine silty soils formed in thick silt in the center of the textured alluvium; and the Ackett, Lud, and valley away from the prevailing winds. These Pigtail soils formed in fine textured alluvium. All soils exhibit no particular pattern of particle size of these soils except the Chiara soils have an distribution (7). Examples are the very deep argillic horizon. In the Idavada area, the Bahem, Portneuf, and Rad soils and the Sluka Pleistocene basalt was eroded and weakly soils that have a duripan. All of these soils are on consolidated ash deposits were exposed. upland terraces. Shallow, ashy soils, such as those of the Weash Shield volcano lava flows from buttes such as series, formed in these deposits. These soils Salmon Butte blocked stream channels. Gravel have a cambic horizon. and gravelly alluvium were deposited in pluvial Pliocene Deposits lakes that formed in areas east of Salmon Butte, in the Deep Creek area north and west of Soils on upland terraces in the southern Hollister, in the Desert Creek area north and east part of the survey area, near Signal and Cedar of Hollister, and in the Rock Creek area. The Buttes, west of Shoshone Creek on Browns Arbidge and Windypoint soils formed in the Bench, and in Shoshone Basin, formed in fine alluvial deposits underlain by gravel. textured Pliocene alluvium (10). Most of these Upper and middle Pleistocene lava in the soils have a mollic epipedon; however, a Snake River Plain underlies the upland terraces rainshadow restricted the development of a in the upper half of Jerome County (11). These mollic epipedon in the Elhina and Tock soils. basalt flows are characterized by pressure Except for the loamy Arness soil, which formed ridges, which are low mounds of exposed rock in material derived from ignimbrite, and the that are about 100 feet across and rise a few feet fine-loamy Chayson soil, which formed in loess above the surrounding landscape (1). Soils on mixed with alluvium, soils that formed in the terraces in areas around these basalt fine textured alluvium have an argillic horizon. outcroppings formed in a mixture of loess and Soils such as those of the Bancy, Budlewis, alluvium. Those soils that formed in areas of Forvic, and Oshone series formed in areas where middle Pleistocene lava flows exhibit greater soil salts and silica were leached and a duripan development. The Hoosegow and Sidlake soils formed. The Aninto and Tanner soils formed in Jerome-Twin Falls, Idaho 239

alluvium derived from acidic rock that did not series, formed in intermediate to acidic material. contain lime or in areas where rainfall was These soils developed ultic characteristics (low insufficient to leach the salts deep into the soil base saturation). Soils that formed in concave, profile. sloping areas on north and east aspects, such as In the southern part of Twin Falls County, those of the Congle, Dehana, and Doodlelink commonly known as the South Hills or Cassia series, developed ultic and pachic Mountains, soils formed in material derived from characteristics. Soils on hill slopes and breaks Pliocene felsitic rock. These Idavada volcanics underlain by volcanic ash, such as those of the are composed of silica welded tuff, volcanic ash, Eep series, are high in content of volcanic ash and lava flows. This broad area slopes to the and have an argillic horizon and ultic north and is sharply faulted and dissected. The characteristics. Soils on the highest hill slopes, rock was uplifted during the late Pliocene as the such as those of the Kavon series, formed in Snake River Plain subsided under the weight of acidic glacial till and colluvium. the lava continuously flowing from the shield On ridges at elevations of less than about volcanoes (1). 6,600 feet, shallow to very deep soils formed in Soils on the breaks and hill slopes formed in intermediate to acidic welded tuff. Examples are welded tuff and volcanic ash (16). Soils at the the Amboat, Brose, and Ragpie soils. These lower elevations, such as those of the Stricker soils have an argillic horizon and ultic series, formed in basic welded tuff and characteristics. The Keman and Rutherford soils developed a calcic horizon. Soils at the higher formed in acidic material on higher summits and elevations, such as those of the Nawt and Player ridges.

241

References

(1) Alt, David D., and Donald W. Hyndman. 1989. Roadside geology of Idaho. pp. 24- 387.

(2) American Association of State Highway [and Transportation] Officials. 1970. Standard specifications for highway materials and methods of sampling and testing. Ed. 10, vol. 2.

(3) American Society for Testing and Materials. 1974. Standard classification of soils for engineering purposes. ASTM Stand. D 2487-69.

(4) Buckman, H. O., and N. C. Brady. 1969. The nature and properties of soils. 625. The MacMillian Co., New York.

(5) Harenberg, W. A., M. L. Jones, I. O’Dell, and S. C. Cordes. Water resources data-Idaho water year 1987. pp. 578-579, 625-629.

(6) Idaho Department of Agriculture and Agricultural Statistics Service. 1988 Idaho agricultural statistics.

(7) Lund, Daryl D., Dal F. Ames, Kimberly A. Blake, and Roger B. Parsons. 1981. A soil-stratigraphy study in the Kimberly-Stricker Butte Area, Twin Falls County, Idaho. Soil Surv. Horiz., pp. 17-22.

(8) Malde, Harold E. 1968. The catastrophic late Pleistocene Bonneville Flood in the Snake River Plain, Idaho. U.S. Gov. Print.Off., Wash., D. C., pp. 1-21.

(9) Portland Cement Association. 1962. PCA soil primer.

(10) Rember, William C., and Earl H. Bennett. 1979. Geologic map of the Twin Falls quadrangle, Idaho. U.S. Geol. Surv., Boise, Idaho.

(11) Scott, William E. 1982. Surficial geologic map of the Eastern Snake River Plain and adjacent areas, 111 to 115 degrees W, Idaho and Wyoming.

(12) United States Department of Agriculture, Soil Conservation Service. 1921. Soil survey of Twin Falls Area, Idaho.

(13) United States Department of Agriculture, Soil Conservation Service. 1927. Soil survey of Jerome Area, Idaho.

(14) United States Department of Agriculture, Soil Conservation Service. 1961. Land capability classification. U.S. Dep. Agric. Handb. 210. 242 Soil Survey

(15) United States Department of Agriculture, Soil Conservation Service. 1975. Soil taxonomy: A basic system of soil classification for making and interpreting soil surveys. U.S. Dep. Agric. Handb. 436.

(16) United States Department of Agriculture, Soil Conservation Service. 1984. Glossary of selected geomorphic terms for western soil surveys.

(17) United States Department of Agriculture, Soil Conservation Service. 1992. Keys to soil taxonomy. 5th ed. Soil Surv. Staff, Soil Manage. Support Serv. Tech. Monogr. 19.

(18) United States Department of Agriculture, Soil Conservation Service. 1951. Soil survey manual. U.S. Dep. Agric. Handb. 18. (Supplements replacing pp. 173-188 issued May 1962) 243

Glossary

Aeration, soil. The exchange of air in soil with inch of soil. The capacity, in inches, in a 60- air from the atmosphere. The air in a well inch profile or to a limiting layer is expressed aerated soil is similar to that in the as: atmosphere; the air in a poorly aerated soil Very low ...... 0 to 3 is considerably higher in carbon dioxide and Low ...... 3 to 6 lower in oxygen. Moderate ...... 6 to 9 Aggregate, soil. Many fine particles held in a High ...... 9 to 12 single mass or cluster. Natural soil Very high ...... more than 12 aggregates, such as granules, blocks, Back slope. The geomorphic component that or prisms, are called peds. Clods are forms the steepest inclined surface and aggregates produced by tillage or principal element of many hillsides. Back logging. slopes in profile are commonly steep, are Alluvial fan. The fanlike deposit of a stream linear, and may or may not include cliff where it issues from a gorge upon a plain segments. or of a tributary stream near or at its junction Badland. Steep or very steep, commonly with its main stream. nonstony, barren land dissected by many Alluvium. Material, such as sand, silt, or clay, intermittent drainage channels. Badland is deposited on land by streams. most common in semiarid and arid regions Animal unit month (AUM). The amount of forage where streams are entrenched in soft required by one mature cow of approximately geologic material. Local relief generally 1,000 pounds weight, with or without a calf, ranges from 25 to 500 feet. Runoff potential for 1 month. is very high, and geologic erosion is active. Area reclaim (in tables). An area difficult to Base saturation. The degree to which material reclaim after the removal of soil for having cation-exchange properties is construction and other uses. Revegetation saturated with exchangeable bases (sum of and erosion control are extremely difficult. Ca, Mg, Na, and K), expressed as a Association, soil. A group of soils or percentage of the total cation-exchange miscellaneous areas geographically capacity. associated in a characteristic repeating Bedrock. The solid rock that underlies the soil pattern and defined and delineated as a and other unconsolidated material or that is single map unit. exposed at the surface. Available water capacity (available moisture Bottom land. The normal flood plain of a stream, capacity). The capacity of soils to hold subject to flooding. water available for use by most plants. It is Boulders. Rock fragments larger than 2 feet (60 commonly defined as the difference between centimeters) in diameter. the amount of soil water at field moisture Breaks. The steep and very steep broken land at capacity and the amount at wilting point. It is the border of an upland summit that is commonly expressed as inches of water per dissected by ravines. 244 Soil Survey

Brush management. Use of mechanical, Clay film. A thin coating of oriented clay on the chemical, or biological methods to make surface of a soil aggregate or lining pores or conditions favorable for reseeding or to root channels. Synonyms: clay coating, clay reduce or eliminate competition from woody skin. vegetation and thus allow understory grasses Claypan. A slowly permeable soil horizon that and forbs to recover. Brush management contains much more clay than the horizons increases forage production and thus reduces above it. A claypan is commonly hard when the hazard of erosion. It can improve the dry and plastic or stiff when wet. habitat for some species of wildlife. Climax plant community. The stabilized plant Calcareous soil. A soil containing enough community on a particular site. The plant calcium carbonate (commonly combined with cover reproduces itself and does not change magnesium carbonate) to effervesce visibly so long as the environment remains the when treated with cold, dilute hydrochloric same. acid. Coarse fragments. Mineral or rock particles California bearing ratio (CBR). The load- larger than 2 millimeters in diameter. supporting capacity of a soil as compared to Coarse textured soil. Sand or loamy sand. that of standard crushed limestone, Cobble (or cobblestone). A rounded or partly expressed as a ratio. First standardized in rounded fragment of rock 3 to 10 inches (7.6 California. A soil having a CBR of 16 to 25 centimeters) in diameter. supports 16 percent of the load that would be Cobbly soil material. Material that is 15 to 35 supported by standard crushed limestone, percent, by volume, rounded or partially per unit area, with the same degree of rounded rock fragments 3 to 10 inches (7.6 to distortion. 25 centimeters) in diameter. Very cobbly soil Canyon. A long, deep, narrow, very steep sided material has 35 to 60 percent of these rock valley with high, precipitous walls in an area fragments, and extremely cobbly soil material of high local relief. has more than 60 percent. Capillary water. Water held as a film around soil Colluvium. Soil material or rock fragments, or particles and in tiny spaces between both, moved by creep, slide, or local wash particles. Surface tension is the adhesive and deposited at the base of steep slopes. force that holds capillary water in the soil. Complex slope. Irregular or variable slope. Cation. An ion carrying a positive charge of Planning or establishing terraces, diversions, electricity. The common soil cations are and other water-control structures on a calcium, potassium, magnesium, sodium, complex slope is difficult. and hydrogen. Complex, soil. A map unit of two or more kinds Cation-exchange capacity. The total amount of of soil or miscellaneous areas in such an exchangeable cations that can be held by the intricate pattern or so small in area that it is soil, expressed in terms of milliequivalents not practical to map them separately at the per 100 grams of soil at neutrality (pH 7.0) or selected scale of mapping. The pattern and at some other stated pH value. The term, as proportion of the soils or miscellaneous areas applied to soils, is synonymous with base- are somewhat similar in all areas. exchange capacity but is more precise in Concretions. Cemented bodies with crude meaning. internal symmetry organized around a point, Chemical treatment. Control of unwanted a line, or a plane. They typically take the form vegetation through the use of chemicals. of concentric layers visible to the naked eye. Chiseling. Tillage with an implement having one Calcium carbonate, iron oxide, and or more soil-penetrating points that shatter or manganese oxide are common compounds loosen hard, compacted layers to a depth making up concretions. If formed in place, below normal plow depth. concretions of iron oxide or manganese oxide Clay. As a soil separate, the mineral soil particles are generally considered a type of less than 0.002 millimeter in diameter. As a redoximorphic concentration. soil textural class, soil material that is 40 Conservation cropping system. Growing crops percent or more clay, less than 45 percent in combination with needed cultural and sand, and less than 40 percent silt. management practices. In a good Jerome-Twin Falls, Idaho 245

conservation cropping system, the soil- soil structure, organic matter content, and improving crops and practices more than fertility and helps to control erosion. offset the effects of the soil-depleting crops Cutbanks cave (in tables). The walls of and practices. Cropping systems are needed excavations tend to cave in or slough. on all tilled soils. Soil-improving practices in a Decreasers. The most heavily grazed climax conservation cropping system include the range plants. Because they are the most use of rotations that contain grasses and palatable, they are the first to be destroyed legumes and the return of crop residue to the by overgrazing. soil. Other practices include the use of green Deferred grazing. Postponing grazing or resting manure crops of grasses and legumes, grazing land for a prescribed period. proper tillage, adequate fertilization, and Dense layer (in tables). A very firm, massive weed and pest control. layer that has a bulk density of more than 1.8 Conservation tillage. A tillage system that does grams per cubic centimeter. Such a layer not invert the soil and that leaves a affects the ease of digging and can affect protective amount of crop residue on the filling and compacting. surface throughout the year. Depth, soil. The total thickness of weathered soil Consistence, soil. Refers to the degree of material over bedrock. In this survey the cohesion and adhesion of soil material and classes of soil depth are as follows: its resistance to deformation when ruptured. Shallow—10 to 20 inches; moderately deep— Consistence includes resistance of soil 20 to 40 inches; deep—40 to 60 inches; very material to rupture and to penetration; deep—60 inches or more. plasticity, toughness, and stickiness of Depth to rock (in tables). Bedrock is too near the puddled soil material; and the manner in surface for the specified use. which the soil material behaves when subject Desert pavement. On a desert surface, a layer of to compression. Terms describing gravel or larger fragments that was emplaced consistence are defined in the “Soil Survey by upward movement of the underlying Manual.” sediments or that remains after finer particles Contour stripcropping. Growing crops in strips have been removed by running water or the that follow the contour. Strips of grass or wind. close-growing crops are alternated with strips Dip slope. A slope of the land surface, roughly of clean-tilled crops or summer fallow. determined by and approximately conforming Control section. The part of the soil on which to the dip of the underlying bedrock. classification is based. The thickness varies Diversion (or diversion terrace). A ridge of among different kinds of soil, but for many it earth, generally a terrace, built to protect is that part of the soil profile between depths downslope areas by diverting runoff from its of 10 inches and 40 or 80 inches. natural course. Corrosion. Soil-induced electrochemical or Drainage class (natural). Refers to the frequency chemical action that dissolves or weakens and duration of wet periods under conditions concrete or uncoated steel. similar to those under which the soil formed. Cover crop. A close-growing crop grown primarily Alterations of the water regime by human to improve and protect the soil between activities, either through drainage or irrigation, periods of regular crop production, or a crop are not a consideration unless they have grown between trees and vines in orchards significantly changed the morphology of the and vineyards. soil. Seven classes of natural soil drainage Crop residue management. Returning crop are recognized—excessively drained, residue to the soil, which helps to maintain somewhat excessively drained, well drained, soil stucture, organic matter content, and moderately well drained, somewhat poorly fertility and helps to control erosion. drained, poorly drained, and very poorly Cropping system. Growing crops according to a drained. These classes are defined in the planned system of rotation and management “Soil Survey Manual.” practices. Drainage, surface. Runoff, or surface flow of Crop residue management. Returning crop water, from an area. residue to the soil, which helps to maintain Duff. A generally firm organic layer on the surface 246 Soil Survey

of mineral soils. It consists of fallen plant Extrusive rock. Igneous rock derived from deep- material that is in the process of seated molten matter (magma) emplaced on decomposition and includes everything from the earth’s surface. the litter on the surface to underlying pure Fallow. Cropland left idle in order to restore humus. productivity through accumulation of Durinode. Weakly cemented to indurated nodule. moisture. Summer fallow is common in Duripan. A subsurface horizon that is cemented regions of limited rainfall where cereal grain is with silica to the degree that fragments do grown. The soil is tilled for at least one not slake during prolonged soaking in water growing season for weed control and or hydrochloric acid. decomposition of plant residue. Eluviation. The movement of material in true Fan terrace. A relict alluvial fan, no longer a site solution or colloidal suspension from one of active deposition, incised by younger and place to another within the soil. Soil horizons lower alluvial surfaces. that have lost material through eluviation are Fast intake (in tables). The rapid movement of eluvial; those that have received material are water into the soil. illuvial. Fertility, soil. The quality that enables a soil to Eolian soil material. Earthy parent material provide plant nutrients, in adequate amounts accumulated through wind action; commonly and in proper balance, for the growth of refers to sandy material in dunes or to loess specified plants when light, moisture, in blankets on the surface. temperature, tilth, and other growth factors Erosion. The wearing away of the land surface are favorable. by water, wind, ice, or other geologic agents Field moisture capacity. The moisture content of and by such processes as gravitational a soil, expressed as a percentage of the creep. ovendry weight, after the gravitational, or Erosion (geologic). Erosion caused by geologic free, water has drained away; the field processes acting over long geologic periods moisture content 2 or 3 days after a soaking and resulting in the wearing away of rain; also called normal field capacity, normal mountains and the building up of such moisture capacity, or capillary capacity. landscape features as flood plains and Fine textured soil. Sandy clay, silty clay, or clay. coastal plains. Synonym: natural erosion. Flood plain. A nearly level alluvial plain that Erosion (accelerated). Erosion much more rapid borders a stream and is subject to flooding than geologic erosion, mainly as a result of unless protected artificially. human or animal activities or of a Foothill. A steeply sloping upland that has relief catastrophe in nature, such as a fire, that of as much as 1,000 feet (300 meters) and exposes the surface. fringes a mountain range or high-plateau Escarpment. A relatively continuous and steep escarpment. slope or cliff breaking the general continuity Foot slope. The inclined surface at the base of a of more gently sloping land surfaces and hill. resulting from erosion or faulting. Synonym: Forb. Any herbaceous plant not a grass or a scarp. sedge. Excess fines (in tables). Excess silt and clay in Fragile (in tables). A soil that is easily damaged the soil. The soil does not provide a source of by use or disturbance. gravel or sand for construction purposes. Frost action (in tables). Freezing and thawing of Excess lime (in tables). Excess carbonates in soil moisture. Frost action can damage roads, the soil that restrict the growth of some buildings and other structures, and plant plants. roots. Excess salts (in tables). Excess water-soluble Genesis, soil. The mode of origin of the soil. salts in the soil that restrict the growth of Refers especially to the processes or soil- most plants. forming factors responsible for the formation Excess sodium (in tables). Excess of the solum, or true soil, from the exchangeable sodium in the soil. The unconsolidated parent material. resulting poor physical properties restrict the Gleyed soil. Soil that formed under poor growth of plants. drainage, resulting in the reduction of iron and Jerome-Twin Falls, Idaho 247

other elements in the profile and in gray generally have slopes of more than 15 colors. percent. The distinction between a hill and a Grassed waterway. A natural or constructed mountain is arbitrary and is dependent on waterway, typically broad and shallow, local usage. seeded to grass as protection against Horizon, soil. A layer of soil, approximately erosion. Conducts surface water away from parallel to the surface, having distinct cropland. characteristics produced by soil-forming Gravel. Rounded or angular fragments of rock as processes. In the identification of soil much as 3 inches (2 millimeters to 7.6 horizons, an uppercase letter represents the centimeters) in diameter. An individual piece major horizons. Numbers or lowercase letters is a pebble. that follow represent subdivisions of the Gravelly soil material. Material that is 15 to 35 major horizons. An explanation of the percent, by volume, rounded or angular rock subdivisions is given in the “Soil Survey fragments, not prominently flattened, as Manual.” The major horizons of mineral soil much as 3 inches (7.6 centimeters) in are as follows: diameter. O horizon.—An organic layer of fresh and Ground water. Water filling all the unblocked decaying plant residue. pores of the material below the water table. A horizon.—The mineral horizon at or near Growing season. The interval between the last the surface in which an accumulation of occurrence of 32 degrees F in spring and the humified organic matter is mixed with the first occurrence of 32 degrees in fall. The mineral material. Also, a plowed surface length of the growing season is expressed horizon, most of which was originally part of as: a B horizon. Very long ...... more than 140 days E horizon.—The mineral horizon in which the Long ...... 100 to140 days main feature is loss of silicate clay, iron, Short ...... 70 to 100 days aluminum, or some combination of these. Very short ...... less than 70 days B horizon.—The mineral horizon below an A Gully. A miniature valley with steep sides cut by horizon. The B horizon is in part a layer of running water and through which water transition from the overlying A to the ordinarily runs only after rainfall. The underlying C horizon. The B horizon also has distinction between a gully and a rill is one of distinctive characteristics, such as (1) depth. A gully generally is an obstacle to accumulation of clay, sesquioxides, humus, farm machinery and is too deep to be or a combination of these; (2) prismatic or obliterated by ordinary tillage; a rill is of blocky structure; (3) redder or browner colors lesser depth and can be smoothed over by than those in the A horizon; or (4) a ordinary tillage. combination of these. Hard bedrock. Bedrock that cannot be C horizon.—The mineral horizon or layer, excavated except by blasting or by the use excluding indurated bedrock, that is little of special equipment that is not commonly affected by soil-forming processes and does used in construction. not have the properties typical of the Hardpan. A hardened or cemented soil horizon, overlying soil material. The material of a C or layer. The soil material is sandy, loamy, or horizon may be either like or unlike that in clayey and is cemented by iron oxide, silica, which the solum formed. If the material is calcium carbonate, or other substance. known to differ from that in the solum, an Hemic soil material (mucky peat). Organic soil Arabic numeral, commonly a 2, precedes the material intermediate in degree of letter C. decomposition between the less decomposed R layer.—Consolidated bedrock beneath the fibric material and the more decomposed soil. The bedrock commonly underlies a C sapric material. horizon, but it can be directly below an A or a Hill. A natural elevation of the land surface, rising B horizon. as much as 1,000 feet above surrounding Humus. The well decomposed, more or less lowlands, commonly of limited summit area stable part of the organic matter in mineral and having a well defined outline; hillsides soils. 248 Soil Survey

Hydrologic soil groups. Refers to soils grouped Invaders. On range, plants that encroach into an according to their runoff potential. The soil area and grow after the climax vegetation has properties that influence this potential are been reduced by grazing. Generally, plants those that affect the minimum rate of water invade following disturbance of the surface. infiltration on a bare soil during periods after Irrigation. Application of water to soils to assist prolonged wetting when the soil is not frozen. in production of crops. Methods of irrigation These properties are depth to a seasonal are: high water table, the infiltration rate and Border.—Water is applied at the upper end of permeability after prolonged wetting, and a strip in which the lateral flow of water is depth to a very slowly permeable layer. The controlled by small earth ridges called border slope and the kind of plant cover are not dikes, or borders. considered but are separate factors in Controlled flooding.—Water is released at predicting runoff. intervals from closely spaced field ditches Igneous rock. Rock formed by solidification from and distributed uniformly over the field. a molten or partially molten state. Major Corrugation.—Water is applied to small, varieties include plutonic and volcanic rock. closely spaced furrows or ditches in fields of Examples are andesite, basalt, and granite. close-growing crops or in orchards so that it Illuviation. The movement of soil material from flows in only one direction. one horizon to another in the soil profile. Furrow.—Water is applied in small ditches Generally, material is removed from an upper made by cultivation implements. Furrows are horizon and deposited in a lower horizon. used for tree and row crops. Impervious soil. A soil through which water, air, Sprinkler.—Water is sprayed over the soil or roots penetrate slowly or not at all. No soil surface through pipes or nozzles from a is absolutely impervious to air and water all pressure system. the time. Lacustrine deposit. Material deposited in lake Increasers. Species in the climax vegetation that water and exposed when the water level is increase in amount as the more desirable lowered or the elevation of the land is raised. plants are reduced by close grazing. Large stones (in tables). Rock fragments 3 Increasers commonly are the shorter plants inches (7.6 centimeters) or more across. and the less palatable to livestock. Large stones adversely affect the specified Infiltration. The downward entry of water into the use of the soil. immediate surface of soil or other material, Leaching. The removal of soluble material from as contrasted with percolation, which is soil or other material by percolating water. movement of water through soil layers or Light textured soil. Sand or loamy sand. material. Liquid limit. The moisture content at which the Infiltration rate. The rate at which water soil passes from a plastic to a liquid state. penetrates the surface of the soil at any Loam. Soil material that is 7 to 27 percent clay given instant, usually expressed in inches particles, 28 to 50 percent silt particles, and per hour. The rate can be limited by the less than 52 percent sand particles. infiltration capacity of the soil or the rate at Loess. Fine grained material, dominantly of silt- which water is applied at the surface. sized particles, deposited by wind. Intake rate. The average rate of water entering Low strength. The soil is not strong enough to the soil under irrigation. Most soils have a support loads. fast initial rate; the rate decreases with Mechanical treatment. Use of mechanical application time. Therefore, intake rate for equipment for seeding, brush management, design purposes is not a constant but is a and other management practices. variable depending on the net irrigation Medium textured soil. Very fine sandy loam, application. loam, silt loam, or silt. Intermittent stream. A stream, or reach of a Mineral soil. Soil that is mainly mineral material stream, that flows for prolonged periods only and low in organic material. Its bulk density is when it receives ground-water discharge or more than that of organic soil. long, continued contributions from melting Minimum tillage. Only the tillage essential to snow or other surface and shallow crop production and prevention of soil subsurface sources. damage. Jerome-Twin Falls, Idaho 249

Miscellaneous area. An area that has little or no Organic matter. Plant and animal residue in the natural soil and supports little or no soil in various stages of decomposition. The vegetation. content of organic matter in the surface layer Moderately coarse textured soil. Coarse sandy is described as follows: loam, sandy loam, or fine sandy loam. Very low ...... less than 0.5 percent Moderately fine textured soil. Clay loam, sandy Low ...... 0.5 to 1.0 percent clay loam, or silty clay loam. Moderately low ...... 1.0 to 2.0 percent Morphology, soil. The physical makeup of the Moderate ...... 2.0 to 4.0 percent soil, including the texture, structure, porosity, High ...... 4.0 to 8.0 percent consistence, color, and other physical, Very high ...... more than 8.0 percent mineral, and biological properties of the Pan. A compact, dense layer in a soil that various horizons, and the thickness and impedes the movement of water and the arrangement of those horizons in the soil growth of roots. For example, hardpan, profile. fragipan, claypan, plowpan, and traffic Mottling, soil. Irregular spots of different colors pan. that vary in number and size. Descriptive Parent material. The unconsolidated organic and terms are as follows: abundance—few, mineral material in which soil forms. common, and many; size—fine, medium, Peat. Unconsolidated material, largely and coarse; and contrast—faint, distinct, and undecomposed organic matter, that has prominent. The size measurements are of accumulated under excess moisture. the diameter along the greatest dimension. Ped. An individual natural soil aggregate, such as Fine indicates less than 5 millimeters ( a granule, a prism, or a block. about 0.2 inch); medium, from 5 to 15 Pedon. The smallest volume that can be called millimeters (about 0.2 to 0.6 inch); and “a soil.” A pedon is three dimensional and coarse, more than 15 millimeters (about 0.6 large enough to permit study of all horizons. inch). Its area ranges from about 10 to 100 square Mountain. A natural elevation of the land feet (1 square meter to 10 square meters), surface, rising more than 1,000 feet above depending on the variability of the soil. surrounding lowlands, commonly of restricted Percolation. The downward movement of water summit area (relative to a plateau) and through the soil. generally having steep sides. A mountain can Percs slowly (in tables). The slow movement of occur as a single, isolated mass or in a group water through the soil adversely affects the forming a chain or range. specified use. Muck. Dark, finely divided, well decomposed Permeability. The quality of the soil that enables organic soil material. (See Sapric soil water or air to move downward through the material.) profile. The rate at which a saturated soil Munsell notation. A designation of color by transmits water is accepted as a measure of degrees of three simple variables—hue, this quality. In soil physics, the rate is value, and chroma. For example, a notation referred to as “saturated hydraulic of 10YR 6/4 is a color with hue of 10YR, conductivity,” which is defined in the “Soil value of 6, and chroma of 4. Survey Manual.” In line with conventional Narrow-base terrace. A terrace no more than 4 usage in the engineering profession and with to 8 feet wide at the base. traditional usage in published soil surveys, Neutral soil. A soil having a pH value of 6.6 to this rate of flow continues to be expressed as 7.3. (See Reaction, soil.) “permeability.” Terms describing permeability, Nutrient, plant. Any element taken in by a plant measured in inches per hour, are as follows: essential to its growth. Plant nutrients are Extremely slow ...... 0.0 to 0.01 inch mainly nitrogen, phosphorus, potassium, Very slow ...... 0.01 to 0.06 inch calcium, magnesium, sulfur, iron, Slow ...... 0.06 to 0.2 inch manganese, copper, boron, and zinc obtained Moderately slow ...... 0.2 to 0.6 inch from the soil and carbon, hydrogen, and Moderate ...... 0.6 inch to 2.0 inches oxygen obtained from the air and water. Moderately rapid ...... 2.0 to 6.0 inches Observed rooting depth. Depth to which roots Rapid ...... 6.0 to 20 inches have been observed to penetrate. Very rapid ...... more than 20 inches 250 Soil Survey

Phase, soil. A subdivision of a soil series based producing a specified plant or sequence of on features that affect its use and plants under specific management. management, such as slope, stoniness, and Profile, soil. A vertical section of the soil flooding. extending through all its horizons and into the pH value. A numerical designation of acidity and parent material. alkalinity in soil. (See Reaction, soil.) Proper grazing use. Grazing at an intensity that Piping (in tables). Formation of subsurface maintains enough cover to protect the soil tunnels or pipelike cavities by water moving and maintain or improve the quantity and through the soil. quality of the desirable vegetation. This Plasticity index. The numerical difference practice increases the vigor and reproduction between the liquid limit and the plastic limit; capacity of the key plants and promotes the the range of moisture content within which accumulation of litter and mulch necessary to the soil remains plastic. conserve soil and water. Plastic limit. The moisture content at which a Range condition. The present composition of the soil changes from semisolid to plastic. plant community on a range site in relation to Playa. The generally dry and nearly level lake the potential natural plant community for that plain that occupies the lowest parts of closed site. Range condition is expressed as depressional areas, such as those on excellent, good, fair, or poor on the basis of intermontane basin floors. Temporary flooding how much the present plant community has occurs primarily in response to precipitation departed from the potential. and runoff. Rangeland. Land on which the potential natural Plowpan. A compacted layer formed in the soil vegetation is predominantly grasses, directly below the plowed layer. grasslike plants, forbs, or shrubs suitable for Ponding. Standing water on soils in closed grazing or browsing. It includes natural depressions. Unless the soils are artificially grasslands, savannas, many wetlands, some drained, the water can be removed only by deserts, tundras, and areas that support percolation or evapotranspiration. certain forb and shrub communities. Poor filter (in tables). Because of rapid or very Range site. An area of rangeland where climate, rapid permeability, the soil may not soil, and relief are sufficiently uniform to adequately filter effluent from a waste produce a distinct natural plant community. A disposal system. range site is the product of all the Poorly graded. Refers to a coarse grained soil environmental factors responsible for its or soil material consisting mainly of particles development. It is typified by an association of nearly the same size. Because there is of species that differ from those on other little difference in size of the particles, range sites in kind or proportion of species or density can be increased only slightly by total production. compaction. Reaction, soil. A measure of acidity or alkalinity Poor outlets (in tables). Refers to areas where of a soil, expressed in pH values. A soil that surface or subsurface drainage outlets are tests to pH 7.0 is described as precisely difficult or expensive to install. neutral in reaction because it is neither acid Potential native plant community. See Climax nor alkaline. The degrees of acidity or plant community. alkalinity, expressed as pH values, are: Potential rooting depth (effective rooting Ultra acid ...... less than 3.5 depth). Depth to which roots could penetrate Extremely acid ...... 3.5 to 4.4 if the content of moisture in the soil were Very strongly acid ...... 4.5 to 5.0 adequate. The soil has no properties Strongly acid ...... 5.1 to 5.5 restricting the penetration of roots to this Moderately acid ...... 5.6 to 6.0 depth. Slightly acid ...... 6.1 to 6.5 Prescribed burning. Deliberately burning an area Neutral ...... 6.6 to 7.3 for specific management purposes, under the Slightly alkaline ...... 7.4 to 7.8 appropriate conditions of weather and soil Moderately alkaline ...... 7.9 to 8.4 moisture and at the proper time of day. Strongly alkaline ...... 8.5 to 9.0 Productivity, soil. The capability of a soil for Very strongly alkaline ...... 9.1 and higher Jerome-Twin Falls, Idaho 251

Relief. The elevations or inequalities of a land from clay; and limestone, formed from soft surface, considered collectively. masses of calcium carbonate. There are Residuum (residual soil material). many intermediate types. Some wind- Unconsolidated, weathered or partly deposited sand is consolidated into weathered mineral material that accumulated sandstone. as consolidated rock disintegrated in place. Seepage (in tables). The movement of water Rill. A steep-sided channel resulting from through the soil. Seepage adversely affects accelerated erosion. A rill generally is a few the specified use. inches deep and not wide enough to be an Series, soil. A group of soils that have profiles obstacle to farm machinery. that are almost alike, except for differences Rippable. Can be penetrated and broken by in texture of the surface layer. All the soils of normal agricultural tillage equipment. a series have horizons that are similar in Rock fragments. Rock or mineral fragments composition, thickness, and arrangement. having a diameter of 2 millimeters or more; Sheet erosion. The removal of a fairly uniform for example, pebbles, cobbles, stones, and layer of soil material from the land surface by boulders. the action of rainfall and surface runoff. Root zone. The part of the soil that can be Shrink-swell (in tables). The shrinking of soil penetrated by plant roots. when dry and the swelling when wet. Rooting depth (in tables). Shallow root zone. The Shrinking and swelling can damage roads, soil is shallow over a layer that greatly dams, building foundations, and other restricts roots. structures. It can also damage plant roots. Runoff. The precipitation discharged into stream Silica. A combination of silicon and oxygen. The channels from an area. The water that flows mineral form is called quartz. off the surface of the land without sinking into Silt. As a soil separate, individual mineral the soil is called surface runoff. Water that particles that range in diameter from the enters the soil before reaching surface upper limit of clay (0.002 millimeter) to the streams is called ground-water runoff or lower limit of very fine sand (0.05 millimeter). seepage flow from ground water. As a soil textural class, soil that is 80 Saline soil. A soil containing soluble salts in an percent or more silt and less than 12 percent amount that impairs growth of plants. A clay. saline soil does not contain excess Sinkhole. A depression in the landscape where exchangeable sodium. The degrees of limestone has been dissolved. salinity, expressed as millimhos per Slickensides. Polished and grooved surfaces centimeter, are: produced by one mass sliding past another. None ...... less than 2 In soils, slickensides may occur at the bases Low ...... 2 to 4 of slip surfaces on the steeper slopes; on Moderate ...... 4 to 8 faces of blocks, prisms, and columns; and in High ...... 8 to 16 swelling clayey soils, where there is marked Very high ...... more than 16 change in moisture content. Sand. As a soil separate, individual rock or Slick spot. A small area of soil having a puddled, mineral fragments from 0.05 millimeter to 2.0 crusted, or smooth surface and an excess of millimeters in diameter. Most sand grains exchangeable sodium. The soil generally is consist of quartz. As a soil textural class, a silty or clayey, is slippery when wet, and is soil that is 85 percent or more sand and not low in productivity. more than 10 percent clay. Slippage (in tables). Soil mass susceptible to Saprolite. Unconsolidated residual material movement downslope when loaded, underlying the soil and grading to hard excavated, or wet. bedrock below. Slope. The inclination of the land surface from Sedimentary rock. Rock made up of particles the horizontal. Percentage of slope is the deposited from suspension in water. The vertical distance divided by horizontal chief kinds of sedimentary rock are distance, then multiplied by 100. Thus, a conglomerate, formed from gravel; slope of 20 percent is a drop of 20 feet in sandstone, formed from sand; shale, formed 100 feet of horizontal distance. In this 252 Soil Survey

survey, classes for simple slopes are as plant and animal activities are largely follows: confined to the solum. Nearly level ...... 0 to 2 percent Stones. Rock fragments 10 to 24 inches (25 to Gently sloping ...... 2 to 4 percent 60 centimeters) in diameter if rounded or 15 Moderately sloping ...... 4 to 8 percent to 24 inches (38 to 60 centimeters) in length Strongly sloping ...... 8 to 20 percent if flat. Moderately steep ...... 20 to 30 percent Stony. Refers to a soil containing stones in Steep ...... 30 to 60 percent numbers that interfere with or prevent tillage. Very steep ...... 60 percent and higher Structure, soil. The arrangement of primary soil Slope (in tables). Slope is great enough that particles into compound particles or special practices are required to ensure aggregates. The principal forms of soil satisfactory performance of the soil for a structure are—platy (laminated), prismatic specific use. (vertical axis of aggregates longer than Slow intake (in tables). The slow movement of horizontal), columnar (prisms with rounded water into the soil. tops), blocky (angular or subangular), and Slow refill (in tables). The slow filling of ponds, granular. Structureless soils are either single resulting from restricted permeability in the grained (each grain by itself, as in dune sand) soil. or massive (the particles adhering without Small stones (in tables). Rock fragments less any regular cleavage, as in many hardpans). than 3 inches (7.6 centimeters) in diameter. Stubble mulch. Stubble or other crop residue left Small stones adversely affect the specified on the soil or partly worked into the soil. It use of the soil. protects the soil from wind erosion and water Soft bedrock. Bedrock that can be excavated erosion after harvest, during preparation of a with trenching machines, backhoes, small seedbed for the next crop, and during the rippers, and other equipment commonly used early growing period of the new crop. in construction. Subsoil. Technically, the B horizon; roughly, the Soil. A natural, three-dimensional body at the part of the solum below plow depth. earth’s surface. It is capable of supporting Subsoiling. Tilling a soil below normal plow plants and has properties resulting from depth, ordinarily to shatter a hardpan or the integrated effect of climate and living claypan. matter acting on earthy parent material, Substratum. The part of the soil below the as conditioned by relief over periods of solum. time. Subsurface layer. Technically, the E horizon. Soil separates. Mineral particles less than 2 Generally refers to a leached horizon lighter millimeters in equivalent diameter and in color and lower in content of organic matter ranging between specified size limits. The than the overlying surface layer. names and sizes, in millimeters, of separates Summer fallow. The tillage of uncropped land recognized in the United States are as during the summer to control weeds and follows: allow storage of moisture in the soil for the Very coarse sand ...... 2.0 to 1.0 growth of a later crop. A practice common in Coarse sand ...... 1.0 to 0.5 semiarid regions, where annual precipitation Medium sand ...... 0.5 to 0.25 is not enough to produce a crop every year. Fine sand ...... 0.25 to 0.10 Summer fallow is frequently practiced before Very fine sand ...... 0.10 to 0.05 planting winter grain. Silt ...... 0.05 to 0.002 Surface layer. The soil ordinarily moved in tillage, Clay ...... less than 0.002 or its equivalent in uncultivated soil, ranging Solum. The upper part of a soil profile, above the in depth from 4 to 10 inches (10 to 25 C horizon, in which the processes of soil centimeters). Frequently designated as the formation are active. The solum in soil “plow layer,” or the “Ap horizon.” consists of the A, E, and B horizons. Taxadjuncts. Soils that cannot be classified in a Generally, the characteristics of the material series recognized in the classification in these horizons are unlike those of the system. Such soils are named for a series material below the solum. The living roots and they strongly resemble and are designated as Jerome-Twin Falls, Idaho 253

taxadjuncts to that series because they Too arid (in tables). The soil is dry most of the differ in ways too small to be of time, and vegetation is difficult to establish. consequence in interpreting their use and Topsoil. The upper part of the soil, which is behavior. Soils are recognized as the most favorable material for plant growth. taxadjuncts only when one or more of their It is ordinarily rich in organic matter and characteristics are slightly outside the is used to topdress roadbanks, lawns, range defined for the family of the series for and land affected by mining. which the soils are named. Toxicity (in tables). Excessive amount of toxic Terrace. An embankment, or ridge, constructed substances, such as sodium or sulfur, that across sloping soils on the contour or at a severely hinder establishment of vegetation slight angle to the contour. The terrace or severely restrict plant growth. intercepts surface runoff so that water Tuff. A compacted deposit that is 50 percent or soaks into the soil or flows slowly to a more volcanic ash and dust. prepared outlet. A terrace in a field generally Unstable fill (in tables). Risk of caving or is built so that the field can be farmed. A sloughing on banks of fill material. terrace intended mainly for drainage has a Upland. Land at a higher elevation, in deep channel that is maintained in permanent general, than the alluvial plain or stream sod. terrace; land above the lowlands along Terrace (geologic). An old alluvial plain, ordinarily streams. flat or undulating, bordering a river, a lake, or Weathering. All physical and chemical changes the sea. produced in rocks or other deposits at or Texture, soil. The relative proportions of sand, near the earth’s surface by atmospheric silt, and clay particles in a mass of soil. The agents. These changes result in basic textural classes, in order of increasing disintegration and decomposition of the proportion of fine particles, are sand, loamy material. sand, sandy loam, loam, silt loam, silt, Well graded. Refers to soil material consisting sandy clay loam, clay loam, silty clay loam, of coarse grained particles that are well sandy clay, silty clay, and clay. The sand, distributed over a wide range in size or loamy sand, and sandy loam classes may diameter. Such soil normally can be easily be further divided by specifying “coarse,” increased in density and bearing properties “fine,” or “very fine.” by compaction. Contrasts with poorly graded Thin layer (in tables). Otherwise suitable soil soil. material that is too thin for the specified Wilting point (or permanent wilting point). The use. moisture content of soil, on an ovendry Tilth, soil. The physical condition of the soil as basis, at which a plant (specifically a related to tillage, seedbed preparation, sunflower) wilts so much that it does not seedling emergence, and root penetration. recover when placed in a humid, dark Toe slope. The outermost inclined surface at chamber. the base of a hill; part of a foot slope.