The Araguaia River is one of the major rivers of Brazil. It has a total length of approximately 2,627 km.

The Araguaia River comes from Goiás-Mato Grosso south borders. From there it flows northeast to a junction with the Tocantins near the town of São João. Along its course, the river forms the border between the states of Goiás, Mato Grosso, Tocantins and Pará. Roughly in the middle of its course the Araguaia splits into two forks (with the western one retaining the name Araguaia and the eastern one being called the Javaés River). These later reunite, forming the Ilha do Bananal, the world's largest river island.

The vein of the Javaés forms a broad inland where it pours back into the main Araguaia, a 100,000 hectare expanse of igapós or flooded forest, blackwater river channels, and oxbow lakes called Cantão, protected by the Cantão State Park. It is one of the biologically richest areas of the eastern Amazon, with over 700 species of birds, nearly 300 species of fish, large populations of species such as the giant otter, the black cayman, the pirarucú, one of the world's largest freshwater fish, and the Araguaian river dolphin (or Araguaian boto), all occurring within a large area.

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