This data set consists of digital water-level-change contours for the High Plains aquifer in the central United States, 1980 to 1997. The High Plains aquifer extends from south of 32 degrees to almost 44 degrees north latitude and from 96 degrees 30 minutes to 104 degrees west longitude. The aquifer underlies about 174,000 square miles in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. This digital data set was created from 5,233 wells measured in both 1980 and 1997. The water-level-change contours were drawn manually on mylar at a scale of 1:1,000,000. The contours then were converted to a digital map.