Originating in the Serra do Cachimbo, it is a tributary of the Tapajós, into which it flows a few kilometers upstream from Itaituba.

[3] It flows through the Itaituba I National Forest, a 220,639 hectares (545,210 acres) sustainable use conservation area established in 1998.

[4] The river basin also contains part of the 538,151 hectares (1,329,800 acres) Rio Novo National Park, a conservation unit created in 2006.

[5] Its hydroelectric potential, along with that of the Tapajós, was assessed by Eletronorte (Centrais Elétricas do Norte do Brasil S.A.), the regional power authority, identifying nine potential dam sites, including four along the Jamanxim.

This article related to a river in Pará, Brazil is a stub.