Patagonian Ice Sheet Patagonian Ice Sheet The Patagonian Ice Sheet was a large elongated and narrow ice sheet centered in the southern Andes that existed during the Llanquihue glaciation. The ice sheet covered all of Chile south of Puerto Montt plus the western fringes of Argentine Patagonia. The ice sheet extended beyond the crest of the Andes into Argentina, but because of the dryness of the climate it did not reach beyond present-day lakes such as the Yagagtoo, Musters, and Colhue Huapi. At its peak (about 18,000-17,500 years ago), the Patagonian Ice Sheet covered about 480,000 km² of land with an estimated ice-volume
Patagonian Desert known by name are those of the Tehuelche complex. Tehuelches lived as hunter-gatherers and did not practise agriculture in lush valleys found in the desert. In the 18th and 19th centuries the northern part of the desert came under Mapuche influence during a process of Araucanization. Mapuches came to practise horse husbandry in the northern part of the Patagonian steppe. Mapuche tribes came to control trade across the desert and traded with the cities of southern Chile as well as Buenos Aires and the Cuyo Region. From the mid-19th century onwards several Argentine and European settlements, some of them sporadic,