The geologic map of the Castle Rock and Long Hollow quadrangles includes 1:24,000 scale mapping of both surficial and bedrock geology. The accompanying report presents new observations about bedrock folds and fracture sets in this portion of the Driftless Area that lies just north of the main Upper Mississippi Valley zinc-lead mineral district. The supplemental GIS data include map unit polygons, field data, well construction report locations, and rasters of geologic contacts.