Gladstone, MI -- U.S. city in Michigan Population (2000): 5032 Housing Units (2000): 2289 Land area (2000): 4.956658 sq. miles (12.837685 sq. km) Water area (2000): 2.928697 sq. miles (7.585289 sq. km) Total area (2000): 7.885355 sq. miles (20.422974 sq. km) FIPS code: 32300 Located within: Michigan (MI), FIPS 26 Location: 45.845808 N, 87.030235 W ZIP Codes (1990): Note: some ZIP codes may be omitted esp. for suburbs. Headwords: Gladstone, MI Gladstone