| 1. |  | Sandwich quadrangle, Illinois : 15 minute series (topographic) | Sandwich (Ill.); Maps; Topographic maps; Topography; Illinois | 1 map : col.; Relief shown by contours and spot heights.; "Culture and drainage in part compiled from aerial photographs taken 1939. Topography by plane-table methods 1948"; "Contour interval 10 feet."... |
