Where Is the Madeira River Located?

The Madeira River is a major tributary of the Amazon River, located in the Amazon Basin of South America.

Key Facts

• Source: Andes Mountains of Bolivia (as the confluence of the Mamoré and Beni rivers).
• Course: Flows northeast through the Brazilian Amazon rainforest (states of Rondônia and Amazonas).
• Mouth: Joins the Amazon River near the city of Manaus, Brazil.
• Rank: Largest tributary of the Amazon by water volume; third longest by length (~3,250 km / 2,020 mi including headwaters).

Significance

The Madeira is a critical transportation artery for the region, a massive source of hydroelectric power (Santo Antônio and Jirau dams), and a biodiversity hotspot. Its sediment-rich "white water" contrasts with the "black water" of rivers like the Negro, creating distinct ecological zones at confluences.