tag:digital.library.illinois.edu,2005:/items/956877e0-82d4-0134-1f08-0050569601ca-6
Illinois, Okawville quadrangle : topography
2022-09-15T18:31:20Z
tag:digital.library.illinois.edu,2005:Item/66787
2016-11-15T17:24:18Z
2022-09-15T18:31:20Z
Illinois, Okawville quadrangle : topography
Contour interval 20 feet.
University of Illinois at Urbana-Champaign Library