- 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 by Air Corps, U.S. Army."; "Surveyed in 1921 and 1928."; "Contour interval 20 feet."; Coordinates: (W 91⁰30ʹ00ʺ--W 91⁰15ʹ00ʺ/N 39⁰45ʹ00ʺ--N 39⁰30ʹ00ʺ). 45 x 35 cm.; 1 map, colored. 1:62,500. Geological Survey (U.S.); Geological Survey Division (Urbana, Ill).