Alabama is the thirtieth largest state in the United States with 52,423 square miles of total area: 3.19% of the area is water, making Alabama twenty-third in the amount of surface water, also giving it the second largest inland waterway system in the United States. The larger metropolitan areas include: Birmingham-Hoover (the largest population region in Alabama constituting roughly 1/4th of the state's population), Mobile, Huntsville, Montgomery, and Tuscaloosa.