Buchanan -- U.S. County in Iowa Population (2000): 21093 Housing Units (2000): 8697 Land area (2000): 571.257853 sq. miles (1479.550983 sq. km) Water area (2000): 2.092602 sq. miles (5.419814 sq. km) Total area (2000): 573.350455 sq. miles (1484.970797 sq. km) Located within: Iowa (IA), FIPS 19 Location: 42.477421 N, 91.863059 W Headwords: Buchanan Buchanan, IA Buchanan County Buchanan County, IA