The U.S. Geological Survey (USGS), in cooperation with the National Oceanographic and Atmospheric Administration’s (NOAA) National Marine Fisheries Service (NMFS), and Florida State University (FSU), collected the data presented here as part of a larger study of seafloor habitats on the shelf edge of the northeastern Gulf of Mexico. It is a pilot study, carried out to demonstrate the utility of geologic mapping to fisheries management issues. This report contains sidescan-sonar mosaics, seismic-reflection profiles, texture and calcium carbonate content of sediment samples and interpretative maps of the seafloor morphology, sediments, and benthic habitats of the study area. The study area is an approximately 150-km2 area along the shelf edge in the northeastern Gulf of Mexico. The site is on the eastern side of the DeSoto Canyon and 75 km due south of Cape San Blas on the Florida panhandle. Water depth ranges from about 50 meters (m) to 120 m. It was chosen because reports from fishermen suggested that high-relief rocky outcrops, which are preferred by gag grouper as spawning aggregation sites, would be abundant. The geologic maps help the fisheries biologists select station locations for ongoing monitoring studies and provide a basis for siting of future reserves.