Parnaíba River

The Parnaíba River is a river in Brazil, which forms the border between the states of Maranhão and Piauí. Its main course is 1,400 km long and the Parnaíba River Basin covers 344,112 km2. The Parnaíba River rises in the Chapada das Mangabeiras range, and flows northeastward to empty into the Atlantic Ocean, being the longest river entirely located within Brazil's Northeast Region. The middle and upper regions of this river are separated by waterfalls, but is otherwise navigable.