This data set consists of digital base of aquifer elevation contours for the High Plains aquifer in the central United States. The High Plains aquifer extends from south of 32 degrees to almost 44 degrees north latitude and from 96 degrees 30 minutes to almost 104 degrees west longitude. The outcrop area covers 174,000 square miles and is present in Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. This digital data set was created by digitizing the base of aquifer elevation contours from a 1:1,000,000 base map created by the U.S. Geological Survey High Plains RASA project (Gutentag, E.D., Heimes, F.J., Krothe, N.C., Luckey, R.R., and Weeks, J.B., 1984, Geohydrology of the High Plains aquifer in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming: U.S. Geological Survey Professional Paper 1400-B, 63 p.) The data should not be used at scales larger than 1:1,000,000.

This digital data set represents the extent of the High Plains aquifer in the central United States. The extent of the High Plains aquifer covers 174,000 square miles in eight states; Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. This data set represents a compilation of information from digital and paper sources and personal communication. This boundary is an update to the boundary published in U.S. Geological Survey Professional Paper 1400-B and Open-File Report 99-267.

This digital data set consists of boundaries for areas of little or no saturated thickness within the High Plains aquifer in the central United States. The High Plains aquifer extends from south of 32 degrees to almost 44 degrees north latitude and from 96 degrees 30 minutes to 106 degrees west longitude. The outcrop area covers 174,000 square miles and is present in Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. This digital data set was created by digitizing the areas of little or no saturated thickness from a 1:1,000,000-scale base map created by the U.S. Geological Survey High Plains Regional Aquifer-Systems Analysis (RASA) project (Gutentag, E.D., Heimes, F.J., Krothe, N.C., Luckey, R.R., and Weeks, J.B., 1984, Geohydrology of the High Plains aquifer in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming: U.S. Geological Survey Professional Paper 1400-B, 63 p.) The data are not intended for use at scales larger than 1:1,000,000.

This digital data set represents the extent of the High Plains aquifer in the central United States. The extent of the High Plains aquifer covers 174,000 square miles in eight states; Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. This data set represents a compilation of information from digital and paper sources and personal communication. This boundary is an update to the boundary published in U.S. Geological Survey Professional Paper 1400-B and Open-File Report 99-267.

This geospatial data set consists of the bedrock formations of the High Plains aquifer, which underlies parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming.

This digital data set consists of contours for predevelopment water-level elevations for the High Plains aquifer in the central United States. The High Plains aquifer extends from south of 32 degrees to almost 44 degrees north latitude and from 96 degrees 30 minutes to 106 degrees west longitude. The outcrop area covers 174,000 square miles and is present in Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. This digital data set was created by digitizing the contours for predevelopment water-level elevations from a 1:1,000,000-scale base map created by the U.S. Geological Survey High Plains Regional Aquifer-System Analysis (RASA) project (Gutentag, E.D., Heimes, F.J., Krothe, N.C., Luckey, R.R., and Weeks, J.B., 1984, Geohydrology of the High Plains aquifer in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming: U.S. Geological Survey Professional Paper 1400-B, 63 p.) The data are not intended for use at scales larger than 1:1,000,000.

This data set consists of digital water-level-change contours for the High Plains aquifer in the Central United States, 1980 to 1996. 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 5,429 wells measured in both 1980 and 1996. The water-level-change contours were drawn manually on mylar. The contours were converted into a digital map at a scale of 1:1,000,000. The data should not be used at scales larger than 1:1,000,000.

This digital data set consists of saturated thickness contours for the High Plains aquifer in Central United States, 1996-97. 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 data set was based on 10,085 water-level measurements, 49 stream elevations, (March 1997) and 10,036 water-level elevations from wells (1,370 from 1996 and 8,666 from 1997) and the base of aquifer value for each measurement location. The saturated thickness at each measurement location was determined by subtracting the water-level elevation from the base of aquifer at that location.