Classification: County
Located in: Illinois (IL)
Total Population (2000): 502266
Total Housing Units (2000): 175524
Land Area (square meters): 2167666114
Water Area (square meters): 32234514
Land Area (square miles): 836.940601
Water Area (square miles): 12.445816
Latitude (decimal degrees): 41.527431
Longitude (decimal degrees): -88.02984
FIPS Code: 17
Place FIPS Code: 197