The Chimehuin River is a river

River

A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...

 in the northwest of the Patagonic

Patagonia

Patagonia is a region located in Argentina and Chile, integrating the southernmost section of the Andes mountains to the southwest towards the Pacific ocean and from the east of the cordillera to the valleys it follows south through Colorado River towards Carmen de Patagones in the Atlantic Ocean...

 Province

Provinces of Argentina

Argentina is subdivided into twenty-three provinces and one autonomous city...

 of Neuquén

Neuquén Province

Neuquén is a province of Argentina, located in the west of the country, at the northern end of Patagonia. It borders Mendoza Province to the north, Rio Negro Province to the southeast, and Chile to the west...

, Argentina

Argentina

Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...

. Its origin is at Lake Huechulafquen

Lake Huechulafquen

Huechulafquen Lake is a lake in Neuquén Province, Patagonian Argentina. This glacial lake is located in the Andean mountains in Lanín National Park some 25 kilometres from Junín de los Andes and 60 kilometres from San Martín de los Andes...

 and it passes by the city of Junín de los Andes

Junín de los Andes

Junín de los Andes is a village in the province of Neuquén, Argentina. It has 10,592 inhabitants as of the , and is the head town of the Huiliches Department...

. After a course of about 53 km, it merges with the Aluminé River

Aluminé River

The Aluminé River is a geographical feature of Neuquén Province, Argentina. It flows southward from Lake Aluminé, near the town of Aluminé, for around 170 km , past which it becomes a tributary of the Collón Curá River ....

 to form the Collón Curá River

Collón Curá River

The Collón Curá River is a geographical feature of Neuquén Province, Argentina. It flows southward from the confluence of the Aluminé and Chimehuin Rivers, near the town of Junín de los Andes, for around 70 km , past which it becomes a tributary of the Limay River.The valley is famous for its...

.

The Chimehuin is considered a prime spot for fly fishing

Fly fishing

Fly fishing is an angling method in which an artificial 'fly' is used to catch fish. The fly is cast using a fly rod, reel, and specialized weighted line. Casting a nearly weightless fly or 'lure' requires casting techniques significantly different from other forms of casting...

. It is known for its two introduced species

Introduced species

An introduced species — or neozoon, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its indigenous or native distributional range, and has arrived in an ecosystem or plant community by human activity, either deliberate or accidental...

 of Salmonidae

Salmonidae

Salmonidae is a family of ray-finned fish, the only living family currently placed in the order Salmoniformes. It includes salmon, trout, chars, freshwater whitefishes and graylings...

, the brown trout

Brown trout

The brown trout and the sea trout are fish of the same species....

 and the rainbow trout

Rainbow trout

The rainbow trout is a species of salmonid native to tributaries of the Pacific Ocean in Asia and North America. The steelhead is a sea run rainbow trout usually returning to freshwater to spawn after 2 to 3 years at sea. In other words, rainbow trout and steelhead trout are the same species....

.

The area around first part of the river's course (from the lake up to a few kilometers before Junín de los Andes) is a protected

Protected area

Protected areas are locations which receive protection because of their recognised natural, ecological and/or cultural values. There are several kinds of protected areas, which vary by level of protection depending on the enabling laws of each country or the regulations of the international...

 nature reserve

Nature reserve

A nature reserve is a protected area of importance for wildlife, flora, fauna or features of geological or other special interest, which is reserved and managed for conservation and to provide special opportunities for study or research...

(Área Natural Protegida Boca del Chimehuin).