Black Warrior River, river in western Alabama, U.S. It is formed by the Locust and Mulberry forks about 20 miles (30 km) west of Birmingham and flows about 180 miles (290 km) southwest to join the Tombigbee River near Demopolis. The river is navigable, and with the Tombigbee it forms a link in the inland waterway between Mobile and Birmingham. It drains an area of 6,275 square miles (16,250 square km). The name is a translation of tuscaloosa, coined from two Choctaw words: tashka (“warrior”) and lusa (“black”).