• Creator
  • Geological Survey (U.S.)
  • Created Date
  • 1923-1923
  • Description
  • Contour interval 20 feet."; "Surveyed in 1920-1921."; "Surveyed in cooperation with the State of Illinois." Coordinates: (W 90⁰45ʹ00ʺ--W 90⁰30ʹ00ʺ/N 41⁰00ʹ00ʺ--N 40⁰45ʹ00ʺ). 45 x 34 cm.; 1 map, colored. 1:62,500. Geological Survey (U.S.); Geological Survey Division (Urbana, Ill.).