The Río Coihueco is a class 3 whitewater run located in the Región de Los Lagos in southern Chile. The river originates from the snowfields of Cerro Puntiagudo and flows through a seldom-visited part of the region, offering a day of mellow whitewater amid notable scenery.

The river is associated with at least two distinct paddling sections. One stretch runs between Puente Coihueco N°1 and Lodge Los Lingues, and another continues from Lodge Los Lingues downstream to the locality of Cancura, covering the final approximately 5 kilometers of the Coihueco before joining the Río Rahue for a short additional kilometer. The section to Cancura takes roughly 5 to 6 hours. The sections beginning at Puente Coihueco N°1 can be completed in approximately 8-hour days. Lodge Los Lingues is situated along Ruta U-55 Osorno–Puerto Octay at kilometer 27.5, in the commune of Puerto Octay, placing the river roughly 20 minutes from Puerto Octay and 30 minutes from Osorno.

The river is noted as suitable for the beginning and end of the season, suggesting that mid-summer flows may be less favorable. As a snowmelt-fed river draining Cerro Puntiagudo, water levels are tied to seasonal snowmelt patterns typical of the southern Chilean Andes.

Beyond whitewater paddling, the Coihueco has a reputation as one of the better fly-fishing rivers in the area around Lago Llanquihue, which lies approximately 25 minutes away. The surrounding landscape reflects the dense native forest characteristic of the Región de Los Lagos. The overall character of the run is described as mellow class 3 whitewater with scenic surroundings, making it accessible to intermediate paddlers looking for a pleasant day on the water rather than a technically demanding descent.