Parnaiba River rises in the Tabatinga Mountains near the border of the state of Goias, Brazil. It flows 850 miles (1,370 kilometers) northeast to the Atlantic Ocean. The river forms the border between the states of Maranhao and Piaui. Its chief tributaries include the Balsas, Gurgueia, Caninde, Poti, and Longa rivers. Ships carry carnauba wax, cotton, rice, and tobacco about 300 miles (480 kilometers) from Floriano to the city of Parnaiba on the Atlantic coast.