Hardin -- U.S. County in Illinois Population (2000): 4800 Housing Units (2000): 2494 Land area (2000): 178.333341 sq. miles (461.881212 sq. km) Water area (2000): 3.199815 sq. miles (8.287483 sq. km) Total area (2000): 181.533156 sq. miles (470.168695 sq. km) Located within: Illinois (IL), FIPS 17 Location: 37.470687 N, 88.281762 W Headwords: Hardin Hardin, IL Hardin County Hardin County, IL