- Geological Survey (U.S.)
- University of Illinois at Urbana-Champaign, University Library
Relief shown by contours and spot heights.; "Culture and drainage in part compiled from aerial photographs taken 1938-1941. Topography by plane-table methods, 1947."; "Contour interval 10 feet. 45 x 35 cm.; 1 map, colored. 1:62,500. Geological Survey (U.S.); Geological Survey Division (Urbana, Ill.).