1940. Geological Survey (U.S.). Culture and drainage in part compiled from aerial photographs taken by Air Corps, U.S. Army.;"Surveyed in 1934.";Relief shown by contours and spot ... Geological Survey (U.S.) and Geological Survey Division (Urbana, Ill.).
1936. Geological Survey (U.S.). Contour interval 20 feet.;"Culture and drainage in part compiled from aerial photographs taken by Air Corps, U.S. Army.";"Surveyed in 1928 and 1933... Geological Survey (U.S.) and Geological Survey Division (Urbana, Ill.).