The U.S. Geological Survey (USGS) collected hydroacoustic data of the St. Croix River adjacent to the Osceola (WI) boat ramp for hydrographic and benthic mapping prior to the reconstruction project implemented by the National Park Service (NPS). This dataset contains predicted geologic substrate information that was interpreted from combined sonar datasets. The shapefile contains a general description of interpreted surficial bottom type with its associated class code in the attribute table. Benthic substrate maps provide important physical characteristics that can be used in habitat modeling to guide management planning of restoration and conservation efforts.