- Geological Survey (U.S.)
- University of Illinois at Urbana-Champaign, University Library
Relief shown by contours and spot heights.; "Topography from aerial photographs by Kelsh plotter and by planetable surveys 1956-1957. Aerial photographs taken 1956."; "Contour interval 10 feet."; Coordinates: (W 89⁰00ʹ00ʺ--W 88⁰45ʹ00ʺ/N 40⁰15ʹ00ʺ--N 40⁰00ʹ00ʺ). 45 x 35 cm.; 1 map, colored. 1:62,500. Geological Survey (U.S.); Geological Survey Division (Urbana, Ill.).