This digital data release contains spatial datasets of bedrock geology, volcanic ash bed locations, test hole locations, bedrock outcrops, and structure contours of the top of bedrock and the base of the Ogallala Group from a previously published map (Souders, 2000). The GeologicMap feature dataset contains separate feature classes for the Ogallala Group map unit (ContactsAndFaults and MapUnitPolys) and the underlying pre-Ogallala bedrock map units (ContactsAndFaults_Bedrock and MapUnitPolys_Bedrock). The VolcanicAshBedPoints feature class contains the locations of volcanic ash beds within the Ogallala Group. The contours depicting the elevation of the top of bedrock (top of Ogallala Group where present and top of pre-Ogallala bedrock where Ogallala is absent) are contained in the IsoValueLines_TopBedrock feature class. The contours depicting the elevation of the base of the Ogallala Group are contained in the IsoValueLines_BaseOgallala feature class. Contoured values are given in both feet and meters. Feature classes containing the location of test holes (TestHolePoints) and bedrock outcrops (OverlayPolys) that were used in generating the structure contour surfaces are included. Nonspatial tables define the data sources used, define terms used in the dataset, and describe the geologic units. A tabular data dictionary describes the entity and attribute information for all attributes of the geospatial data and the accompanying nonspatial tables. Surficial geologic units that are only represented as cross-sections on the original map publication, and the cross-sections themselves, are not included in this digital data release.