Plymouth -- U.S. County in Iowa Population (2000): 24849 Housing Units (2000): 9880 Land area (2000): 863.564324 sq. miles (2236.621237 sq. km) Water area (2000): 0.393972 sq. miles (1.020382 sq. km) Total area (2000): 863.958296 sq. miles (2237.641619 sq. km) Located within: Iowa (IA), FIPS 19 Location: 42.752959 N, 96.206675 W Headwords: Plymouth Plymouth, IA Plymouth County Plymouth County, IA