Tapajós

The Tapajós (Portuguese: Rio Tapajós [ˈhi.u tapaˈʒɔs]) 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 2,080 km (1,290 mi) long. Prior to a drastic increase in illegal gold mining and consequent soil erosion it was one of the largest clearwater rivers and currently is an anthropogenic whitewater river, accounting for about 6% of the water in the Amazon basin.

Source: Wikipedia https://en.wikipedia.org/wiki/Tapajós