WATER RESOURCES OF BIG HORN COUNTY, WYOMING By Maria Plafcan, Earl W. Cassidy, and Myron L. Smalley U.S. GEOLOGICAL SURVEY Water-Resources Investigations Report 93-4021 Prepared in cooperation with the WYOMING STATE ENGINEER Cheyenne, Wyoming 1993 U.S. DEPARTMENT OF THE INTERIOR BRUCE BABBITT, JR., Secretary U.S. GEOLOGICAL SURVEY ROBERT M. HIRSCH, Acting Director For additional information Copies of this report can be write to: purchased from: District Chief U.S. Geological Survey U.S. Geological Survey Earth Science Information Center Water Resources Division Open-File Reports Section 2617 E. Lincolnway, Suite B Box 25286, Denver Federal Center Cheyenne, Wyoming 82001-5662 Denver, Colorado 80225 CONTENTS Page Abstract......................................................................................................................................................................... 1 Introduction.......................................................................................^ 2 Purpose and scope............................................................................................................................................... 4 Physiography...................................................................................................................................................... 4 Climate................................................................................................................................................................ 5 Geology............................................................................................................................................................... 5 Water-right administration By Richard G. Stockdale, Wyoming State Engineer's Office ................................................................ 10 Acknowledgments.............................................................................................................................................. 22 Streamflow.................................................................................................................................................................... 22 Streamflow data.................................................................................................................................................. 22 Streamflow characteristics.................................................................................................................................. 22 Stream types ............................................................................................................................................. 27 Flow duration............................................................................................................................................ 29 Low flows................................................................................................................................................. 32 High flows................................................................................................................................................. 33 Ground water................................................................................................................................................................ 34 Ground-water data.............................................................................................................................................. 34 Unconsolidated aquifers..................................................................................................................................... 39 Alluvium andcolluvium........................................................................................................................... 39 Gravel, pediment, and fan deposits........................................................................................................... 39 Bedrock aquifers................................................................................................................................................. 42 Cenozoic and Mesozoic rocks.................................................................................................................. 42 Tertiary rocks.................................................................................................................................. 46 Will wood Formation .............................................................................................................. 46 Fort Union Formation............................................................................................................. 46 Cretaceous rocks............................................................................................................................. 46 Upper Cretaceous rocks ......................................................................................................... 46 Lower Cretaceous rocks......................................................................................................... 47 Jurassic and Triassic rocks.............................................................................................................. 48 Paleozoic rocks......................................................................................................................................... 48 Tensleep Sandstone......................................................................................................................... 49 Madison Limestone, Darby Formation, and Bighorn Dolomite..................................................... 50 Flathead Sandstone......................................................................................................................... 51 Precambrian rocks.................................................................................................................................... 52 Changes in water levels and hydraulic heads..................................................................................................... 52 Seasonal water-level changes in unconsolidated deposits........................................................................ 52 Seasonal water-level changes in Cenozoic and Mesozoic rocks.............................................................. 53 Seasonal and daily changes in hydraulic head in flowing wells............................................................... 53 Long-term changes in hydraulic head and yield of flowing wells............................................................ 53 Water use....................................................................................................................................................................... 55 Water quality................................................................................................................................................................. 56 Streamflow-quality data...................................................................................................................................... 59 Streamflow quality.............................................................................................................................................. 63 Ground-water-quality data.................................................................................................................................. 65 Ground-water quality and suitability for specific uses....................................................................................... 66 Domestic use............................................................................................................................................. 67 Agricultural and livestock use.................................................................................................................. 67 Industrial use............................................................................................................................................. 69 CONTENTS iii CONTENTS-Continued Page Ground-water quality in unconsolidated aquifers............................................................................................... 69 Alluvium andcolluvium........................................................................................................................... 71 Gravel, pediment, and fan deposits........................................................................................................... 71 Ground-water quality in bedrock aquifers.......................................................................................................... 75 Agricultural pesticides in water.......................................................................................................................... 75 Stream-water samples............................................................................................................................... 75 Streambed-material samples..................................................................................................................... 77 Ground-water samples.............................................................................................................................. 77 Radionuclides in ground water........................................................................................................................... 81 Summaiy..................................................................................................................................................^ 84 Selected references......................................................................................................................................................