Located to the east of the Department of Cochabamba, the reserve occupies the Southwest of the Department of the Beni, between the Provinces Yacuma and Ballivian. The municipalities involved are San Borja and Santa Ana del Yacuma. The surface area is 135,000 hectares (1.350km2). The climate is hot tropical with rainy summers.
The annual precipitation varies between 1,400 mm in the driest years to the 3,000 mm in the most humid. The average altitude is 220 meters. The topography is essentially flat with scarce differences of levels in large extensions.
The reserve has a typical insular bio-geographic position. It is an archipelago of alluvial forests surrounded by savannahs and humid regions.
815 registered species of large plants are found, estimating the existence of up to 1,500 species. Among flora the most common species are the mara, palo maria, cedar, ochoo, tajibo purple, cuchi, pachiuba palm and the jatata. The vegetation constitutes an intricate mosaic of forests, wetlands and savannahs. 852 species of fauna were registered. The most important ones are the pejichi, marimono, manechi, jaguar, swamp deer, harpy eagle, black duck, river peta, lizard and black cayman. Up to now 480 species of birds were identified. The population is chiefly Chimane and Camba.