Río Jáchal is one of the significant rivers of San Juan Province in Argentina, flowing as a major waterway within the broader Andean river system of the region. Together with the Río San Juan, it forms part of the Desaguadero/Colorado river system that ultimately drains to the Atlantic Ocean. The river receives its Andean tributaries from the northern reaches of San Juan Province, distinguishing it geographically from its southern counterpart, the Río San Juan, which draws from the west and southwest. The Jáchal's Andean origins give it the character of a freestone mountain river, fed by snowmelt and precipitation from high-altitude terrain, with flows and conditions that shift meaningfully across seasons. The river passes through a dramatic landscape shaped by the geology of the Andes and the arid Cuyo region, offering anglers a remote and scenic setting that is characteristic of Patagonian and pre-Andean fishing destinations in western Argentina.