Contour interval 20 feet.;"Illinos culture and drainage in part compiled from aerial photographs taken by Air Corps, U.S. Army";"Surveyed in 1926";Relief shown by contours and spot heights.;1 map, colored;45 x 36 cm.;1:62,500
The University of Illinois Map Library requests the following acknowledgement be included when using this Historical Map: Map provided courtesy of the Map Library at the University of Illinois at Urbana-Champaign.; No Copyright - United States; http://rightsstatements.org/vocab/NoC-US/1.0/