Location and access: In the Talamanca Range along the upper reachesof the Río Grande de Orosi. Much of the 16 km, between the town of Orosi and the park administration building is paved.

This same point is 35 km from San José. The area is covered by a dense, evergreen rainforest in which there are some 150 rivers and streams. It contains 211 species of birds as well as many mammals such as the jaguar and the ocelot. The greater part is completly unexplored due to the extreme denseness of the forest. The reserve is a good place to see the famous quetzal.