Madison -- U.S. County in Montana Population (2000): 6851 Housing Units (2000): 4671 Land area (2000): 3586.539776 sq. miles (9289.094981 sq. km) Water area (2000): 16.307155 sq. miles (42.235337 sq. km) Total area (2000): 3602.846931 sq. miles (9331.330318 sq. km) Located within: Montana (MT), FIPS 30 Location: 45.435828 N, 111.932243 W Headwords: Madison Madison, MT Madison County Madison County, MT