It flows into the Amazon River (Solimões section) at the city of Manacapuru, about 80 km (50 mi) upstream (west) from Manaus.

Parts of the river are very broad, appearing as elongated lakes, with the uppermost known as Lago Grande de Manacapuru ("Large Manacapuru Lake") and the lowermost, near where it merges into the Amazon, as Lago Manacapuru ("Lake Manacapuru").

On February 7, 2009, a plane crashed at the river.

24 of the 28 people onboard were killed.

This article related to a river in the Brazilian state of Amazonas is a stub.