When the first Spaniards arrived to what is today Mendoza’s territory they come upon two indigenous groups: the Huarpes living North of the Diamante River and partially of the Atuel River and the Puelches Algarroberos or Puelches de Cuyo living South of these two rivers towards the Neuquén Province and coming from the Maule Chilean region.
As from 1858 they start crossing over the Andes attracted by the abundance of cattle and horses in the argentine Pampas and the strong pressures put on them by the warring Spaniards. They thus become nomadic and begin to mix with the peoples from Mendoza, La Pampa, Buenos Aires and Patagonia and produce the so-called “Araucanization” phenomenon (Araucanos being another native people).
These new generations influenced by Araucanos were fierce warriors who attacked cultivated areas, cities and villages. The River Plate Viceroyship adopting defensive policies in order to protect the populated areas, founded the San Rafael del Diamante Fort by decree of Viceroy Rafael de Sobremonte on 2nd April 1805 on the shores of the river.
The ruins are still there in the present 25 de Mayo district. At the beginning of the 20th Century two thirds of the fort is devastated by floods. It was declared Historical National Monument on 10th December 1942.
Playa de San Rafael, 12 kilometers from the fort enters the scene in 1860 with the development of agriculture.
Many visionary men started arriving soon, planning and building irrigation canals coming from the Diamante River and, in 1870 with arrival of Julio Ballofet these systems are ameliorated and the orderly division of land begins to be implemented.
In 1883, Rodolfo Iselin, a good pioneer friend of Ballofet designs the plan for the formation of a French Colony thus attracting new investors for breeding cattle, and planting fruit trees and vineyards. The railway arrives to San Rafael in 1903 and greatly strengthens commercial links with Buenos Aires.
A Provincial decree from 7 October 1922 declares de Villa de San Rafael a City. From then onwards San Rafael grows steadily in the agricultural field, except for some and downs as the one produced in 1932 produced by the eruption of the Descabezado Volcano which harmed the local economy.
During the 1980’s, the agricultural sector area suffers deep harm produced by climatic changes. Adventure tourism begins to appear on the horizon as an alternative product, exploiting the beauty offered by natural resources and sceneries present in San Rafael. It has by now become a par excellence pole of attraction for the Mendoza Province.