Classification: County
Located in: Illinois (IL)
Total Population (2000): 644356
Total Housing Units (2000): 225919
Land Area (square meters): 1159184623
Water Area (square meters): 2383790404
Land Area (square miles): 447.563704
Water Area (square miles): 920.38666
Latitude (decimal degrees): 42.313322
Longitude (decimal degrees): -87.983801
FIPS Code: 17
Place FIPS Code: 97