1. Illinois, Rushville quadrangle Maps University Of Illinois Urbana Champaign Public content 1958. Geological Survey (U.S.). Contour interval 20 feet.;"Surveyed in 1922-1923";Relief shown by contours and spot heights.;1 map, colored;45 x 35 cm.;1:62,500. Geological Survey Division (Urbana, Ill.) and U.S. Geological Survey (U.S.).