A geologic map showing the configuration of the bedrock surface for the North Platte, Nebraska, 1- by 2-degree quadrangle was published at a scale of 1:250,000 in 1991. This report describes the conversion of the bedrock-surface elevation map into a digital geographic data set and includes those data at a nominal scale of 1:500,000. A film separation of the published elevation contours was scanned to produce a file of digital graphics data. The digital graphics data were processed further to produce a digital geographic data set. Geographic feature attributes and data-set documentation also are included in the digital data set. The digital geographic data are formatted for distribution in accordance with the Spatial Data Transfer Standard approved by the U.S. National Institute of Standards and Technology.