Classification: County
Located in: Illinois (IL)
Total Population (2000): 404119
Total Housing Units (2000): 138998
Land Area (square meters): 1347922501
Water Area (square meters): 9439462
Land Area (square miles): 520.435809
Water Area (square miles): 3.644597
Latitude (decimal degrees): 41.918229
Longitude (decimal degrees): -88.338441
FIPS Code: 17
Place FIPS Code: 89