Río Aguas Calientes is a high-altitude river located in the Puna region of Catamarca Province, Argentina, flowing at an elevation of approximately 4,063 meters (roughly 13,330 feet) above sea level. This remote and rugged waterway sits within the precordillera landscape of northwestern Argentina, where the extreme elevation shapes nearly every aspect of the fishing experience. The river's name — meaning "hot waters" — reflects the geothermal influences present in the region, and its high-altitude Puna setting gives it a character unlike lowland rivers. The combination of cold, clear mountain water, sparse human presence, and a unique native fish community alongside introduced salmonids makes Río Aguas Calientes a genuinely wild and adventurous destination for anglers willing to make the journey.