- Geological Survey (U.S.)
- University of Illinois at Urbana-Champaign, University Library
Relief shown by contours and spot heights.; "Surveyed in 1927-1928"; "Contour interval 10 feet"; Shows roadway classification as of 1931.; Coordinates: (W 89⁰30ʹ00ʺ--W 89⁰15ʹ00ʺ/N 40⁰45ʹ00ʺ--N 40⁰30ʹ00ʺ). 45 x 34 cm.; 1 map, colored. 1:62,500. Geological Survey (U.S.); Geological Survey Division (Urbana, Ill.).