Columbia -- U.S. County in Washington Population (2000): 4064 Housing Units (2000): 2018 Land area (2000): 868.814404 sq. miles (2250.218881 sq. km) Water area (2000): 4.714629 sq. miles (12.210833 sq. km) Total area (2000): 873.529033 sq. miles (2262.429714 sq. km) Located within: Washington (WA), FIPS 53 Location: 46.337053 N, 117.958346 W Headwords: Columbia Columbia, WA Columbia County Columbia County, WA