Summary: | This report describes the geography, geology, and ground-water resources of Rawlins County in northwestern Kansas. The hydrologic and geologic information was obtained in the field during the summer of 1952. The field data upon which this report is based are given in tables; they include records of 226 wells, chemical analyses of water from 21 representative wells, and logs of 36 test holes and one well. Rawlins County lies in the High Plains section of the Great Plains physiographic province. It is drained for the most part by Beaver Creek and its tributaries and by Sappa Creeks. The topography in general is an eastward sloping, gently rolling plain, deeply dissected along the valley walls of the principal streams. The climate is subhumid to semiarid, the average annual precipitation being about 18.5 inches. Farming is the principal industry of the county; wheat and cattle are the chief products. The Pierre shale of late Cretaceous age underlies the entire county, and crops out in a few places along valley walls or floors. The Ogallala formation of Pliocene age overlies the Pierre shale and is one of the principal water-bearing formations of the county. The Meade formation of Kansan age, which overlies the Ogallala formation at a few isolated points, contains a bed of volcanic ash that has been worked on a small scale for commercial use. The Sanborn formation of Illinoian and Wisconsinan age overlies the Ogallala formation or the Meade formation where it is present. The Crete member of the Sanborn formation is composed of sand and gravel in a terrace position and yields moderate to large quantities of water to wells. Alluvium and undifferentiated low terrace deposits of Wisconsinan and Recent age yield quantities of water adequate for irrigation and municipal supplies. The report contains a map showing the areas of outcrop of the rock formations and the location of test holes and wells for which records are given. The shape and slope of the water table in Rawlins County are shown by means of water-table ...
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