- 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 1940. Topography by plane-table methods, 1947."; "Contour interval 10 feet. 45 x 34 cm.; 1 map, colored. 1:62,500. Geological Survey (U.S.); Geological Survey Division (Urbana, Ill.).