The Río Teno is a 102-kilometer river in the Maule Region of central Chile, draining a basin of approximately 1,590 square kilometers. It originates at the confluence of the Malo and Nacimiento rivers, with headwaters north of Planchón volcano at the Lagunas de Teno. The river flows northwest through the Andes before turning southwestward near Curicó, eventually joining the Lontué River to form the Mataquito River near the locality of Sagrada Familia. At Los Queñes, the Teno is joined by the Río Claro, which drains glaciers of the Planchón-Peteroa volcanic complex.

The primary paddling section runs approximately 25 kilometers from a put-in at around 1,150 meters elevation, accessed by driving east from the Pan-American Highway near Curicó through Romeral to Los Queñes — a total of about 46 kilometers — then continuing 25 kilometers upstream past the Carabinero checkpoint. The take-out is at Los Queñes at approximately 675 meters elevation. The road parallels virtually the entire run, making scouting straightforward. The character of the river shifts along its length: a short, sheer-walled canyon about 22 kilometers above Los Queñes contrasts with the broader glacially-carved valley above and below it. The upper section includes a narrow gorge with class 4–5 whitewater, while the main 25-kilometer stretch is predominantly class 3–4 with some class 5-plus sections and mandatory portages. About 2.5 kilometers into the run, paddlers must portage around a hazardous combination of sieves, logs, and a road culvert. Below that, gradient eases before a gauging station, after which a 500-meter set of cataracts requires scouting. The river then returns to class 3–4 rock-garden rapids down to Los Queñes. At high water, the river loses definition and eddies, becoming a fast roller coaster with surfing waves. Below the confluence with the Río Claro, the river doubles in volume, offering additional surfing opportunities.

Optimal flows occur in spring and summer, with a broad range of 500 to 3,000 CFS. The river runs brown and turbid from snowmelt beginning around September. The Río Teno hosts the Los Queñes River Fest, a national kayak circuit event held in early November, which includes both kayaking and rafting competitions. Birdlife along the corridor is notable, and waterfalls are visible from the river. Accommodation and catering are available in Los Queñes, with local outfitters operating instructional and guided trips from the area.