Patagonian Desert albeit to the west, where precipitation is higher, bushes are replaced by grasses. Topographically the deserts consist of alternating tablelands and massifs dissected by river valleys and canyons. The more western parts of the steppe host lakes of glacial origin and grades into barren mountains or cold temperate forests along valleys. Inhabited by hunter-gatherers since Pre-Hispanic times, the desert faced migration in the 19th century of Mapuches, Chileans, Argentines, Welsh, and other European peoples, transforming it from a conflictive borderland zone to an integral part of Argentina, with cattle, sheep and horse husbandry being the primary land uses. The Patagonian
Patagonian Desert Desert is the largest of the 40° parallel and is a large cold winter desert, where the temperature rarely exceeds 12 °C and averages just 3 °C. The region experiences about seven months of winter and five months of summer. Frost is not uncommon in the desert but, due to the very dry condition year round, snow is rare. The Andes, to the desert's west, are the primary reason for the Patagonian desert status as they inhibit the westerly flow of moisture from the southern Pacific from reaching inland. This creates a rain shadow that accounts for the formation of