1. Bedrock-surface altitude in the midwestern basins and arches region of Indiana, Ohio, Michigan, and Illinois Author/Creator: Geological Survey (U.S.), cartographer Publication/Creation: Columbus, Ohio : U.S. Department of the Interior, U.S. Geological Survey, 1993 Resource Type: Map Access & Availability: Loading
2. Geology, structure, and thickness of hydrogeologic units in part of the Columbia Plateau, Oregon Author/Creator: Geological Survey (U.S.), cartographer Publication/Creation: Portland, Oregon : Department of the Interior, United States Geological Survey, 1990 Resource Type: Map Access & Availability: Loading