Bedrock Geology, Altitude of Base, and 1980 Saturated Thickness of the High Plains Aquifer in Parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming

HA-648 Bedrock geology, altitude of base, and 1980 saturated thickness of the high plains aquifer in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming, scale 1:2,000,000, 1981, ISBN 978-0-607-76647-9 Keywords: Hydrogeology, Hydrology, Topographic maps