tag:digital.library.illinois.edu,2005:/itemsItems2022-09-15T18:31:48Ztag:digital.library.illinois.edu,2005:Item/699382016-11-30T19:19:24Z2022-09-15T18:31:48ZIllinois-Indiana, Mount Carmel quadrangle : topographyContour interval 20 feet.University of Illinois at Urbana-Champaign Library