The Río Arias o Arenales is a watercourse in the province of Salta, Argentina, located within the broader Plata River basin. It flows through the area of Villa San Lorenzo, where a notable trail leads from the town to meet the river and the nearby Las Costas Water Reserve. This trail is highly rated by users, suggesting the area is a popular destination for outdoor recreation. The river's banks, specifically near Villa Palacios, have been subject to illegal dumping incidents, which local municipal authorities actively work to prevent. This indicates paddlers should be aware of potential water quality issues in certain sections. For paddlers, the river offers several access points and boat ramps. A specific facility known as Camping Xamena is highlighted as a point of interest for paddlers, providing amenities and serving as a potential launch site. The overall character of the paddling experience appears to be recreational and accessible, focused on day trips rather than extended expeditions. The surrounding area includes the Reserva Hídrica Río Arenales (Arenales River Water Reserve), which underscores the environmental significance of the watershed. The presence of established access points, a nearby camping facility, and its proximity to Villa San Lorenzo make it a viable destination for casual paddling and fishing excursions in the region.