The sources of the river are in the 116,748 hectares (288,490 acres) Monte Roraima National Park, created in 1989.[2] The larger part of the Ireng River basin forms the frontier between Brazil and Guyana. Ireng's main tributaries are the Uailan and Canã rivers on the Brazilian side and the Cacó, Dacã and Socobi rivers on the Guyanese side. All of these rivers merge with the upper and middle sections of the Ireng.