Fishing in Parque Nacional Aconquija

Parque Nacional Aconquija sits in the Tucumán and Catamarca provinces of northwestern Argentina, protecting the eastern slopes and high country of the Sierra del Aconquija.

The park's waters are mountain rivers and streams fed by those slopes, along with at least one high-altitude lake.

This is not Patagonian trout country in the classic sense — it is subtropical highland, and the fishing here carries a conservation context that shapes everything about how you go.

The two species available to anglers are both exotic invaders: rainbow trout (Oncorhynchus mykiss), present in various rivers and streams throughout the park, and pejerrey (Odontesthes bonariensis), found in Laguna del Tesoro.

The park's management is explicit that fishing here is a tool for controlling these introduced species, which have been present since before the park was established and continue to impact native biodiversity. That framing matters on the water.

Río de los Alisos, Río Cochuna, Río de las Pavas, and Río de las Cañas are among the rivers where trout are present. These are the kind of streams you wade — mountain water dropping through forested terrain on the Aconquija slopes.

The fishing regulations, approved in August 2025 under Resolution 242/2025 of the Administración de Parques Nacionales, reflect the management goal directly: there is no catch-and-release requirement, no closed season, and no bag or size limits for the two exotic species in authorized sectors.

The park wants these fish removed. A free permit is required, issued by the Intendencia del Parque Nacional Aconquija — check the park's current process for how to request one. The permit is valid for one year and is personal and non-transferable.

When you finish fishing, you are required to submit a catch report noting the site, species, number, and size of fish taken. That data feeds a monitoring program tracking how the activity affects native species recovery.

You are fishing inside a protected area that is actively trying to restore what was here before the trout arrived. That is a different kind of trip than most — and an honest one.