The Río Negro is one of the principal tributaries of the Rahue River in the Los Lagos Region of southern Chile. It originates in the Coastal Precordillera and flows from south to north, draining part of the eastern slopes of the Cordillera Pelada, before joining the Rahue River at an elevation of approximately 26 meters. The commune of Río Negro takes its name from the river.

The local tourism office of Río Negro has organized guided kayak descents on the river, running from Puente Esmeralda downstream to Puente Chapaco. Organizers have described the river as presenting minimal technical complexity, making it accessible to paddlers without advanced whitewater skills. These organized events have included safety personnel and a specialized kayak instructor, reflecting a cautious approach to the river even at lower difficulty levels. Participation in organized descents has been limited to adults aged 18 and over.

Given how little is publicly documented about this river's seasonal conditions, water temperature, hazards, and independent access logistics, paddlers planning a trip should contact the Unidad de Turismo of the Municipalidad de Río Negro directly for current guidance on put-in and take-out access, safety considerations, and any requirements for paddling the river independently.