Conservation Commission, Stanley Coulter, Chairman.' 'The base used ... is the Ryse map, which has been modified.' Includes geologic cross sections. Scale 1:253,440. 1 inch = 4 miles Division of Geology, W.N. Logan, state geologist.
[Creator not found] (1932). Geological map of Indiana. Indiana Department of Conservation. https://purl.dlib.indiana.edu/iudl/images/VAC3073/VAC3073-M-00989 (map)