| 1. |  | Illinois, Oakland quadrangle. | Oakland (Ill.); Illinois; Maps; Topographic maps; Topography | 1 map : col.; Relief shown by contours and spot heights.; "Culture and drainage in part compiled from aerial photographs taken by Air Corps, U.S. Army."; "Surveyed in 1922, 1935 and 1936."; "Contour interval... |
