This digital data release contains geospatial data for the geologic map of the O’Neill 1 degree by 2 degree geologic map in Nebraska, originally published in 2008 by R.E. Diffendal and others. The original map consists of a 1:250,000 scale map plate with a “stack unit” structure showing multiple overlying units, as well as several roughly 1:750,000 scale maps in an accompanying pamphlet showing bedrock geology and structure contours. To capture as much of this content as possible in a geodatabase, three “layers” are included in this database: 1) Overlay polygons showing Quaternary loess deposits (Qes) where they overlay older Quaternary units; 2) a layer (consisting of line and polygon feature classes) showing Quaternary and bedrock units as depicted on the published 1:250,000 scale map (with the exception of Qes as described above), 3) a “bedrock” layer (consisting of line and polygon feature classes), showing pre-Quaternary units. Vector data were created by a combination of exporting vectors from published PDF files and hand digitizing against georegistered images of the published map and associated pamphlet figures. Required fields and non-spatial tables were populated with data from the printed map and pamphlet. The spatial data are accompanied by non-spatial tables that describe the sources of geologic information, a description of geologic map units, a glossary of terms, and a Data Dictionary that duplicates the Entity and Attribute information contained in the metadata file.