DEPARTMENT OF THE INTERIOR JOHN BARTON PAYNE, Secretary UNITED STATES GEOLOGICAL SURVEY GEORGE OTIS SMITH, Director Bulletin 713 GEOGRAPHY, GEOLOGY, AND MINERAL RESOURCES OF THE FORT HALL INDIAN RESERVATION IDAHO BY G. R. MANSFIELD WITH A CHAPTER ON WATER RESOURCES BY W. B. HEROY OHIO £TAr4 E JiWERSHY. WASHINGTON GOVERNMENT PRINTING OFFICE 1920 ADDITIONAL COPIES OF THIS PUBLICATION MAY BE PROCURED FROM THE SUPERINTENDENT OF DOCUMENTS GOVERNMENT PRINTING OFFICE WASHINGTON, D. C. AT 50 CENTS PER COPY V CONTENTS. Page. Abstract of report_____________________________ 7 Introduction__________________________________ 9 Location of the area_______ _____________________.. 9 Early exploration and history_____________________.._ 12 Geography ______________________________.______ 14- Physiographic development..______________'._____ 14 Subaerial erosion______________..__'._______________ 14 Putnam cycle ___________________^__ _ 15 Gibson cycle____ _ ___________________ 16 Spring Creek cycle___________________________ 17 Volcanic features_________________________ ___ 17 Drainage relations ____________________________ 18 Climate, by W. B. Heroy___________________________ 19 Vegetation and animal life_____.___________________ 22 Adaptations of life to environment________.___________ 23 Industries___________________________________ 23 Resources____:_____________________________ 24 Transportation ________________________________ 24 Power______________..__..______________:____ 24 Geology ____ _ __________________ _________ 25 Previous geologic work_________.________________ 25 Stratigraphy___________________.._____________ 27 General character and age of the rocks _________ _____ 27 Cambrian system_________ _________________ 30 Ordovician system __ ____ _________________ 32 Garden City limestone ________________ 32 Swan Peak quartzite_______________________ 32 Fish Haven dolomite-_'____________________ 33 Silurian system___ ____ ____ ________ __ __ 34 Laketown dolomite____..__________________ 34 Devonian system_______________ ___. _____ _______ 34 Jefferson limestone-_________________________ 34 Threeforks (?) limestone_ ____ __ 34 Carboniferous system______________ ____ _________ 35 Mississippian series-_ _ _ __ 35 Madison limestone.___ _ _ __________ 35 Brazer limestone .._________ ________________ 35 Pennsylvanian series ________ _ _ ____ 36 Wells formation___ ____ _________ 36 Permian series_____ _ _ _ 38 Phosphoria formation_________ _ _ _______ 38 Occurrence 38 Phosphate shales____________________ 38 Bex chert member_____ _ __ 41 4 CONTENTS. Geology Continued. Stratigraphy Continued. Page. Triassic system.______________________ 42 Occurrence and subdivisions______________ 42 Review of nomenclature ______________ 42 Lower Triassic formations_____________ ______ 45 General character_________________:__.__ 45 Woodside shale_____________________ __ 45 Thaynes group _________________ 46 General character_______________________ 46 Ross Fork limestone___________________ 46 Fort Hall formation__________________ 48 Portneuf limestone _________________ _ 49 Timothy sandstone_______ __;___________ 50 Triassic (?) formations __ _________ ___ 51 Age 51 Higham grit____ _ 51 Deadman limestone __ _ _____ ___ 52 Wood shale____________________________ 52 Jurassic system________________1___________ 52 Occurrence and subdivision___________________ 52 . Nugget sandstone_ __________________ 52 Twin Creek limestone ____________________ 53 Tertiary system ...__.. __ ___ 54 Salt Lake formation (Pilocene?)________________ 54 Undifferentiated Tertiary and Quaternary rocks_________ 55 Quaternary system __^ 56 Subdivisions ___ ____________ 56 Older alluvium____ ________________________ 56 Recent alluvium ____________ 57 Travertine ___ __________ 57 Igneous rocks __ ____ 57 Structure ___ _ ____ 61 Folding_________ _._______ 61 Faulting ..___________ 62 Putnam overthrust ______________ 62 Other faults__ ____________ 65 Epochs of deformation _________________ 65 Geologic history : 66 Description of townships __________ 71 T. 3 S., R. 36 E_______________________________ 71 T. 4 S., R. 36 E______ ______________________ 73 T. 3 S., R. 37 E_______ ______________________ 77 T. 4 S., R. 37 E______ _______________________ 83 T. 5 S., R. 37 E_______________________________ 87 T. 3 S., R. 38 E_________________________________ 92 T. 4 S., R. 38 E_______________________________ 95 T. 5 S., R. 38 E_____________*___________________ 99 T. 6 S., R. 38 E________ ______________________ 103 Mineral resources________ _ _ _ _ 105 Phosphate deposits___________ __________________ ____ 105 General summary of tonnage estimates______________ 105 Utilization of western phosphate- ___________ ____ 106 CONTENTS. 5 Mineral resources Continued. Phosphate deposits Continued. Page. Development and production__________________ 106 Status of western phosphate lands.____________ 108 Origin of the deposits__________________________ 108 Coal prospects_____________________________ 114 Metalliferous deposits__________.___________'. .______ 115 Prospects _____________/___________________ 115 Gold placers______________________________ 115 Fort Hall mining district________________________ 116 Volcanic ash ________________________________ 117 Soils..________________'.__________________________________ .118 Water resources of the Fort Hall Indian Reservation, by W. B. Heroy_ 119 Field work and acknowledgments____________________ 119 Surface water_________________________________ 119 Snake River basin__________________________ 119 Blackfoot River basin_________________________ 122 Portneuf River basin....________________________ 127 Bannock Creek basin___:____________________ 132 Ground water_________________________________ 133 Occurrence in the mountainous areas_______________ 133 _ Occurrence in Snake River valley________________i_ 133 Utilization of water____________________________ 140 Domestic use_______________________________ 140 Irrigation__'._____________________________________ 141 Bannock Valley _________________________ 141 Fort Hall irrigation project___________________ 141 Portneuf project _______________ 143 Fort Hall bottoms_________________________ 143 Water power______________________________ 144 Snake River____________________________ 144 Blackfoot River_________________________ 145 Bannock Creek___________________________ 147 Portneuf River _ ___ _______________ 148 Ross Fork ,___________________________ 148 Lincoln Creek___________________________ 148 Index____ ________________ ___________^_______ 149 ILLUSTRATIONS. Page. PLATE I. A, Panorama of North and South Putnam mountains; B, Dam of Blackfoot River Reservoir; C, Panoramic view west through the narrows of Ross Fork canyon___________ 16 II. A, Characteristic strike ridge of Higham grit, in sec. IS, T. 3 S., R. 38 E.; B, Cedar tree in vigorous condition growing pros­ trate because of exposure to high winds____________ 18 III. Topographic and geologic map and sections of the Fort Hall In­ dian Reservation, Idaho____________________In pocket. IV. A, Volcanic hills (augite-quartz latite) in the NW. I sec.. 30, T. 3 S., R. 36 E., surmounted by little cone; B, Nearer view of the cone shown iu A___________________________ 72 V. Detailed geologic map of T. 3 S., R. 37 E., with structure sec­ tions_____________-______-________________ 78 VI. Detailed geologic map of T. 4 S., R. 37 E., with structure sec­ tions__________ _-_ ___ _ __ ____ 82 VII. Detailed geologic map of T. 5 ; S., R. 37 E., with structure sec­ tions_________________________________ 86 VIII. Detailed geologic map of T. 3 S., R. 38 E., with structure sec­ tions______________ ___ _________ 92 I.. Detailed geologic map of T. 4 S., R. 38 E., with structure sec­ tions__________________________________ 96 X. Detailed geologic map of T. 5 S., R. 38 E., with structure sec­ tions_________ ___ ___________ 100 XI. A., Characteristic exposure of volcanic ash in sec. 11, T. 4 S., R. 36 E.; B, Exposure and wind sculpture of volcanic ash on Starlight Creek, T. 8 S., R. 33 E_________________ 116 XII. A, Lower portion of Blackfoot River canyon and adjacent Snake River valley; B, Canyon of Blackfoot River, sec. 10, T. 3 S., R. 38 E., showing relation of cliffs and talus slopes to river_ 122 XIII. Map of the Fort Hall Indian Reservation and vicinity, illustrat­ ing water resources_ _ - __-___-_______ 133 FIGURE 1. Index map of Idaho showing the location of the Fort Hall Indian Reservation_________________________ 10 2. Map showing the location of the Fort Hall Indian Reservation with respect to the phosphate reserve and the location of areas of the reserve examined in previous years_______ 11 3. Diagram showing variation in annual precipitation in vicinity of Fort Hall Indian Reservation during the years 1891 to 1915__________________________________ 20 4. Diagram showing relation between maximum, mean, and mini­ mum monthly temperature at American Falls, Idaho Falls, and Pocatello, Idaho _ ____ 21 6 OHIO STATE UNIVERSITY. ABSTRACT OF REPORT. Introduction. The Fort Hall Indian Reservation, which was examined in 1913, includes about 800 square miles in Bingham, Ban­ nock, and Power counties, Idaho, and has been partly included in the Idaho phosphate reserve. Its interesting history is briefly out­ lined. Geography. The reservation contains two mountainous regions with broad valleys and an intervening area of plains bordering Snake River. The maximum difference in elevation is about 4,500 feet, and the broader valleys range from about 4,400 to 5,800 feet in elevation. The drainage is all tributary