Río de las Vacas is a mountain stream flowing through the high Andes of Mendoza Province, Argentina. It originates in the glaciated peaks surrounding Aconcagua and converges with the Cuevas and Tupungato rivers at the locality of Punta de Vacas (elevation 2,394 meters above sea level) to form the Mendoza River. Fed primarily by glacial melt and snowpack from the surrounding Andean peaks, this is a classic freestone stream characterized by cold, clear water and the rugged, dramatic scenery of the Central Andes. The river runs through a high-altitude valley corridor, making it one of the more remote and wild trout fisheries in the Mendoza region.