The Purus River is a tributary of the Amazon River in South America.
It is 3,382 km long.
Its drainage basin is 371,042 km2 (143,260 sq mi), and the mean annual discharge is 11,207 m3/s (395,800 cu ft/s). The river shares its name with the Alto Purús National Park and the Purús Province (and its conformed Purús District), one of the four provinces of Peru in the Ucayali Region.
The Purus River rises in Peru. It defines the boundary between Peru and Brazil in the centre of the state of Acre, then runs for a short distance along the boundary of the 231,555 hectares (572,180 acres) Santa Rosa do Purus National Forest, a sustainable use conservation unit created in 2001 after it is joined by the Santa Rosa River. It then flows north east through Manoel Urbano. It runs through a continuous forest at the bottom of the great depression, lying between the Madeira River, which skirts the edge of the Brazilian sandstone plateau, and the Ucayali River, which hugs the base of the Andes.
