- 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 1950. Topography by plane-table surveys 1954."; "Contour interval 10 feet."; Coordinates: (W 89⁰15ʹ00ʺ--W 89⁰00ʹ00ʺ/N 40⁰00ʹ00ʺ--N 39⁰45ʹ00ʺ). 45 x 35 cm.; 1 map, colored. 1:62,500. Geological Survey (U.S.); Geological Survey Division (Urbana, Ill.).