According to the U.S. Census Bureau , the county has a total area of 589 square miles ( 1,530 km2 ) , of which 586 square miles ( 1,520 km2 ) is land and 3.1 square miles ( 8.0 km2 ) ( 0.5 % ) is water .
The county has a total area of 589 square miles ( 1,530 km2 ) .