1. Digital data set of water-level changes in the High Plains aquifer in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming, 1980 to 1996 Author/Creator: Geological Survey (U.S.) Publication/Creation: Lincoln, Neb. : U.S. Geological Survey, 2002 Resource Type: Map Edition: Last update: 3 Apr 2002. Access & Availability: Loading