São Francisco

São Francisco, river, eastern Brazil. It rises in the state of Minas Gerais, flows north, north-east, and south to the Atlantic Ocean, and in its lower course separates the states of Bahia and Sergipe from the states of Pernambuco and Alagoas. About 2,897 km (1,800 mi) long with a drainage area of 551,410 sq km (212,900 sq mi), it is navigable in its middle course for 1,368 km (850 mi), but in its lower course navigation is interrupted at three points. These interruptions are: at the rapids of Pirapóra; near the border of Bahia State; and where it breaks through the granite wall of the coast range to form the Paulo Afonso Falls; traffic is carried past this last point by a railway line. The river flows into the Atlantic Ocean north-east of Aracaju. Its average discharge is 2.9 million litres (638,000 gallons) per second, and it is the largest river wholly within Brazil.