Clay -- U.S. County in Florida Population (2000): 140814 Housing Units (2000): 53748 Land area (2000): 601.107492 sq. miles (1556.861192 sq. km) Water area (2000): 42.586405 sq. miles (110.298278 sq. km) Total area (2000): 643.693897 sq. miles (1667.159470 sq. km) Located within: Florida (FL), FIPS 12 Location: 30.000401 N, 81.823736 W Headwords: Clay Clay, FL Clay County Clay County, FL