Jefferson -- U.S. County in Florida Population (2000): 12902 Housing Units (2000): 5251 Land area (2000): 597.736137 sq. miles (1548.129422 sq. km) Water area (2000): 38.911432 sq. miles (100.780141 sq. km) Total area (2000): 636.647569 sq. miles (1648.909563 sq. km) Located within: Florida (FL), FIPS 12 Location: 30.510187 N, 83.884229 W Headwords: Jefferson Jefferson, FL Jefferson County Jefferson County, FL