Classification: County
Located in: Illinois (IL)
Total Population (2000): 278418
Total Housing Units (2000): 114404
Land Area (square meters): 1330572400
Water Area (square meters): 14340767
Land Area (square miles): 513.736898
Water Area (square miles): 5.537001
Latitude (decimal degrees): 42.311119
Longitude (decimal degrees): -89.08163
FIPS Code: 17
Place FIPS Code: 201