| 1. |  | Illinois, Decatur quadrangle | Illinois; Maps; Topographic maps; Topography; Decatur (Ill.) | 1 map : col.; Relief shown by contours and spot heights.; "Contour interval 10 feet"; "Surveyed in 1929"; Shows roadway classification as of 1932.; Coordinates: (W 89⁰00ʹ00ʺ--W 88⁰45ʹ00ʺ/N 40⁰00ʹ00ʺ--N... |