- Geological Survey (U.S.)
- University of Illinois at Urbana-Champaign, University Library
Relief shown by contours and spot heights.; "Surveyed in 1907-1908."; "Surveyed in cooperation with the State of Illinois."; Coordinates: (W 88⁰00ʹ00ʺ--W 87⁰45ʹ00ʺ/N 39⁰00ʹ00ʺ--N 38⁰45ʹ00ʺ). 45 x 36 cm.; 1 map, colored. 1:62,500. Geological Survey (U.S.); Geological Survey Division (Urbana, Ill.).