Iriri River Terra do Meio Ecological Station. The river varies greatly in volume depending on the season, and in the dry season include waterfalls, rocks and rapids. The Iriri River flows through the Tapajós-Xingu moist forests ecoregion. The river is rich in fish, including many species found only here and in the Xingu. Large sections remain unexplored due to its remoteness in a region surrounded by Amazon rainforest, and sections with strong current and cataracts. Iriri River The Iriri River () is a large tributary of the Xingu River in Brazil, in the state of Pará. It is long making it the
Xingu peoples European slavers arrived in the Xingu region around 1750. Xinuguano population was estimated in the tens of thousands but was dramatically reduced by diseases and slavery by Europeans. In the centuries since the penetration of the Europeans into South America, the Xingu fled from different regions to escape modernization and cultural assimilation. Nonetheless settlers made it up as far as the upper run of the Rio Xingu. By the end of the 19th century, about 3,000 natives lived at the Alto Xingu, where their current political status has kept them protected against European intruders. By the mid twentieth century this