| 1. |  | Illinois-Indiana, Calumet quadrangle : topographic sheet | Illinois; Maps; Topographic maps; Topography; Calumet Region (Ill. and Ind.); Cook County (Ill.); Lake County (Ind.); Indiana | 1 map : col.; Relief shown by contours.; "Contour interval 10 feet"; "Surveyed in 1889, 1897 and 1899." |