| 1. |  | Illinois-Waukegan, Waukegan quadrangle : topography | Maps; Topographic maps; Topography; Illinois; Wisconsin; Waukegan (Ill.) | 1 map : col.; Relief indicated by contours and spot heights.; "Surveyed in 1906."; "Surveyed in cooperation with the State of Illinois."; "Contour interval 10 feet." |