St. Tammany -- U.S. Parish in Louisiana Population (2000): 191268 Housing Units (2000): 75398 Land area (2000): 854.151691 sq. miles (2212.242631 sq. km) Water area (2000): 269.931822 sq. miles (699.120181 sq. km) Total area (2000): 1124.083513 sq. miles (2911.362812 sq. km) Located within: Louisiana (LA), FIPS 22 Location: 30.398425 N, 89.930622 W Headwords: St. Tammany St. Tammany, LA St. Tammany Parish St. Tammany Parish, LA