Patagonian Desert

The region comprises the southern section of the Andes Mountains with lakes, fjords, temperate rainforests, and glaciers in the west and deserts, tablelands and steppes to the east.

As the southern Andes rose in the Middle Miocene (14–12 million years ago) the resulting rain shadow originated the Patagonian Desert to the east.

Cuyo and Eastern Patagonia is rain shadowed from the prevailing westerly winds by the Andes range and is arid. The aridity of the lands next to eastern piedmont of the Andes decreases to the south due to a decrease in the height of the Andes with the consequence that the Patagonian Desert develop more fully at the Atlantic coast contributing to shaping the climatic pattern known as the Arid Diagonal. The Argentinian wine region of Cuyo and Northern Patagonia is almost completely dependent on irrigation, using water drawn from the many rivers that drain glacial ice from the Andes.

The Conquest of the Desert (Conquista del desierto) was an Argentine military campaign directed mainly by General Julio Argentino Roca in the 1870s with the intention of establishing dominance over the Patagonian Desert, inhabited primarily by indigenous peoples.

Established on 11 May 1937, it hosts a representative sample of Magellanic subpolar forest and west Patagonian steppe biodiversity in good state of conservation.

The lagoon is situated in the Patagonian steppe, surrounded by hills and gorges.

The Patagonian steppe, while barren at first glance, is inhabited by a considerable variety of plants.

The ecoregion merges into the Patagonian steppe in the south and southwest.

To the north the grasslands adjoin the Patagonian steppe ecoregion.

The heart of the park is the Chacabuco Valley, a biologically important east-west valley that forms a pass over the Andes Mountains and a transition zone between the Patagonian steppe grasslands of Argentinian Patagonia and the southern beech forests of Chilean Patagonia to the west.