Tombigbee (tŏmbĭgˈbē) [key], river, c.400 mi (640 km) long, rising in NE Miss. and flowing SE into W Alabama, then generally S to join the Alabama River and form the Mobile River before entering into Mobile Bay at Mobile. The Tombigbee is an important artery for manufactured goods. Dams and locks improve navigation on the river. In 1972 construction was begun on a canal between the Tombigbee and Tennessee rivers. The 253-mi (407-km) waterway, completed in 1984, is another modern link in a navigable system from the Tennessee Valley to the Gulf Coast.