Amazon river dolphin widespread river dolphins. They are present in six countries in South America: Bolivia, Brazil, Colombia, Ecuador, Peru, and Venezuela, in an area covering about . The boundaries are set by waterfalls, such as the Xingu and Tapajós rivers in Brazil, as well as very shallow water. A series of rapids and waterfalls in the Madeira River have isolated one population, recognized as the subspecies "I. g. boliviensis", in the southern part of the Amazon basin in Bolivia. They are also distributed in the basin of the Orinoco River, except the Caroni River and the upper Caura River in Venezuela. The
Xingu Indigenous Park April. The headwaters of the Xingu River are in the south of the park. The area covered by the park was defined in 1961 and covers parts of the municipalities of Canarana, Paranatinga, São Félix do Araguaia, São José do Xingu, Gaúcha do Norte, Feliz Natal, Querência, União do Sul, Nova Ubiratã and Marcelândia in the state of Mato Grosso. The national park was created after a campaign by the Villas-Bôas brothers for protection of the region. An account of the exploration of this area by the Villas-Bôas brothers and their efforts to protect the region is documented in the