BENI RIVER

Spanish Ro Beni, river in Bolivia, formed by many confluents arising in the north sector of the Cordillera Real north of La Paz, the national capital. It flows northeast through the densely forested Yungas, or northeastern Andean slopes, and plains. It is joined by the Madre de Dios River at Riberalta and flows on to its junction with the Mamor River at Villa Bella, on the Brazilian border, after a course of 1,000 miles (1,600 km). The Beni and the Mamor form the Madeira River, which constitutes the extreme northeastern border of Bolivia. Steam navigation is possible on the Beni during high water (December to May), between Rurrenabaque, at the base of the Andes, and the Esperanza rapids near its junction with the Mamor.