Monroe -- U.S. County in Missouri Population (2000): 9311 Housing Units (2000): 4565 Land area (2000): 645.982029 sq. miles (1673.085704 sq. km) Water area (2000): 24.243987 sq. miles (62.791636 sq. km) Total area (2000): 670.226016 sq. miles (1735.877340 sq. km) Located within: Missouri (MO), FIPS 29 Location: 39.511236 N, 91.990523 W Headwords: Monroe Monroe, MO Monroe County Monroe County, MO