1. Geohydrology of the High Plains Aquifer system, Cheyenne urban area, Wyoming, 1991 Yale Public content 1994. 2002-06-01T04:00:00Z. 2002-06-01T04:00:00Z. Geological Survey (U.S.). The Survey ; Open-File Services Section, distributor. English. Public. Wyoming, Cheyenne Region, and High Plains Aquifer.