In 1981, Jim Quinlan and Joe Ray first published, “Groundwater Basins of the Mammoth Cave Region, Kentucky, Showing Springs, Major Caves, Flow Routes, and Potentiometric Surface.” Occasional Publication. Mammoth Cave, Kentucky: Friends of the Karst. Since then the springs, cave entrances, flow routes, and inferred drainage basins have been digitized as shapefiles for use in GIS analyses. These are available through the Geospatial Data Library at the University of Kentucky, Kentucky Geological Survey website (https://www.uky.edu/KGS/gis/kgs_gis.htm), under the Karst Dye Traces link. This current dataset complements the existing one by making the potentiometric surface available as georeferenced files for use in GIS. I georeferenced the original paper map (Quinlan and Ray, 1981) and then digitized the groundwater potentiometric surface contours. These are in the data set as the shapefiles, QuinlanAndRay_GWContours_16N.* A raster surface was then interpolated using these lines and is available here as PotentiometricSurfaceInterpolated.bil.