The Tapajós (Portuguese: Rio Tapajós [ˈʁi.u tɐpɐˈʒɔs]) is a river in Brazil. It runs through the Amazon Rainforest and is a major tributary of the Amazon River. When combined with the Juruena River, the Tapajós is approximately 1,200 mi (1,900 km) long.[1] It is one of the largest clearwater rivers,[2] accounting for about 6% of the water in the Amazon basin.[3]