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-Tocantins-Araguaia moist forests ecoregion rises into the Carajás Mountains, where it becomes interspersed with areas of seasonal forest and cerrado. Population centers include São Félix do Xingu on the Xingu, Porto de Moz, Oeiras do Pará and Gurupá on the Amazon, and Marabá on the Tocantins. The Marajó várzea at the mouth of the Amazon lies to the north. To the west, on the other side of the Xingu River, is the Tapajós-Xingu moist forests. To the northeast is the Tocantins/Pindare moist forests. To the southeast and south the ecoregion blends into the Mato Grosso seasonal forests ecoregion, and in some places directly