This digital geospatial data set consists of structure contours of the top of the Laramie-Fox Hills aquifer along the Front Range of Colorado. The U.S. Geological Survey developed this data set as part of a project described in the report, "Structure, Outcrop, and Subcrop of the Bedrock Aquifers Along the Western Margin of the Denver Basin, Colorado" (Robson and others, 1998).

This digital geospatial data set consists of structure contours of the base of the Laramie-Fox Hills aquifer and the base of the Arapahoe aquifer along the Front Range of Colorado. The U.S. Geological Survey developed this data set as part of a project described in the report, "Structure, Outcrop, and Subcrop of the Bedrock Aquifers Along the Western Margin of the Denver Basin, Colorado" (Robson and others, 1998).

This digital geospatial data set consists of structure contours of the base of the Laramie-Fox Hills aquifer and the base of the Arapahoe aquifer along the Front Range of Colorado. The U.S. Geological Survey developed this data set as part of a project described in the report, "Structure, Outcrop, and Subcrop of the Bedrock Aquifers Along the Western Margin of the Denver Basin, Colorado" (Robson and others, 1998).

This digital geospatial data set consists of structure contours on the base of the upper member of the Arapahoe aquifer. The U.S. Geological Survey developed this data set as part of a project described in the report, "Structure, Outcrop, and Subcrop of the Bedrock Aquifers Along the Western Margin of the Denver Basin, Colorado" (Robson and others, 1998).

This digital geospatial data set consists of structure contours on the base of the upper member of the Arapahoe aquifer. The U.S. Geological Survey developed this data set as part of a project described in the report, "Structure, Outcrop, and Subcrop of the Bedrock Aquifers Along the Western Margin of the Denver Basin, Colorado" (Robson and others, 1998).

Several pre-existing datasets that characterize portions of the Northern High Plains aquifer base were merged together in order to define the entire base of the Northern High Plains aquifer. This digital dataset consists of the aquifer base elevation contours (100-foot contour interval) for the northern portion of the High Plains aquifer in the central United States. The boundaries were chosen to simplify boundary conditions for a computer simulation model being used for a hydrologic study of the Northern High Plains.

Several pre-existing datasets that characterize portions of the Northern High Plains aquifer base were merged together in order to define the entire base of the Northern High Plains aquifer. This digital dataset consists of the aquifer base elevation contours (100-foot contour interval) for the northern portion of the High Plains aquifer in the central United States. The boundaries were chosen to simplify boundary conditions for a computer simulation model being used for a hydrologic study of the Northern High Plains.

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 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 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.