Ottawa -- U.S. County in Michigan Population (2000): 238314 Housing Units (2000): 86856 Land area (2000): 565.653939 sq. miles (1465.036914 sq. km) Water area (2000): 1066.315188 sq. miles (2761.743542 sq. km) Total area (2000): 1631.969127 sq. miles (4226.780456 sq. km) Located within: Michigan (MI), FIPS 26 Location: 42.929975 N, 86.049749 W Headwords: Ottawa Ottawa, MI Ottawa County Ottawa County, MI