The Juruena River is a 1240 km long river in west-central Brazil, in the state of Mato Grosso. For the last 190 km of its lower part the river becomes the border between the states Mato Grosso and Amazonas. It finally joins the Teles Pires river to form the Tapajós river, which is one of the biggest tributaries to the Amazon River. The river is the site of the Juruena National Park as well as the Salto Augusto Falls. Juruena National Park was created on June 5, 2006, and covers 19,000 km².