Renaico River is a Chile

Chile

Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...

an river that, along all its length, straddles the border between the regions of Biobío and Araucanía

Araucanía Region

The IX Araucanía Region is one of Chile's 15 first order administrative divisions and comprises two provinces: Malleco in the north and Cautín in the south....

.Renaico River rises from the northwest flank of Cordillera de Pemehue, a western spur of the Andes

Andes

The Andes is the world's longest continental mountain range. It is a continual range of highlands along the western coast of South America. This range is about long, about to wide , and of an average height of about .Along its length, the Andes is split into several ranges, which are separated...

 Mountains, north of Tolhuaca

Tolhuaca (volcano)

Tolhuaca Volcano is a stratovolcano located in the northern part of the Araucanía Region of Chile. The volcano has been shaped by glacial erosion, which contrasts with the relatively smooth slopes of its neighbor Lonquimay, due to the younger age of this latter volcano.The volcano dominates the...

 volcano. In its upper course, the river parallels the east and north border of Malleco National Reserve. The river terminates approximately 7 km downstream from the city of Renaico, where it joins the Vergara River

Vergara River

Vergara River is a river located in the Intermediate Depression of Chile. The river rises at the junction of the Malleco and Rehue rivers, close to the city of Angol.Nahuelbuta Range barrier forces the river to flow northward. At the latitude of the town of Renaico, the Vergara is joined by its...

.