Mapped by the Geological Survey. Filing title: Ridge Farm, Ill.-Ind. Edition of 1947. Polyconic projection. Relief shown by contours and spot heights. Contour interval 20 feet. Shows portions of Edgar and Vermilion County, Illinois. Vermillion County, Indiana, labeled as "Unsurveyed area." Mapped by the Geological Survey 1945. At head of map: "State of Illinois, Dwight H. Green, Governor, Department of Registration and Education, Frank G. Thompson, Director, Geological Survey Division, M. M. Leighton, Chief, Urbana, Illinois." "N3945--W8730/15."
Imprint: [Washington, D.C.] : U.S. Geological Survey, [1947]
Dimensions: 45 x 42 cm or smaller