tag:digital.library.illinois.edu,2005:/items/a1b271a0-994e-0134-2096-0050569601ca-3Illinois, Liberty quadrangle2022-09-15T18:31:51Ztag:digital.library.illinois.edu,2005:Item/699992016-11-30T19:19:47Z2022-09-15T18:31:51ZIllinois, Liberty quadrangleContour interval 20 feet.University of Illinois at Urbana-Champaign Library