When the first Spaniards discovered Mendoza territory, they found two Indian tribes: the Huarpes, that occupied the north of the Diamante and part of the Atuel; and the Puelches Algarroberos or the Cuyo Puelches, located at the south of these rivers toward Neuquén. Starting in 1858 Indians from the Chilean region of Maule began to cross the mountain range in massively motivated by the great number of bovine and equine livestock of the Argentinian Pampas and the strong pressures and wars with the Spaniards. They became nómadic, mixing with the natural tribes from Mendoza, La Pampa, Buenos Aires and Patagonia. It was the process called Araucanización. The Araucanian new generations emphasized the attacks against farms, cities and villages. For this reason the Viceroyalty of the Plate River (Virreinato del Río de la Plata), according to the implemented defensive politics created the Fort San Rafael del Diamante on the riverbank of the homonymous river in April 2nd, 1805. It was a bill written by the Viceroy Rafael of Sobremonte. Today you can see its ruins, inside the Villa 25 de Mayo. At the beginning of the century an alluvium of the Diamante River razed two thirds parts of the Fort. In December 10th 1942 it was declared National Historical Monument. In 1860 San Rafael Beach entered in scene located 12 km to the east of the Villa (Fort) for the agriculture development. In a short time visionary men arrived planning and building the first big channels from the Diamante river. Engineer Julio Balloffet's arrival in 1870, improved the irrigation systems and division of lands. In 1883 Rodolfo Iselín, a pioneer friend of Balloffet, started the French Colony attracting new investors in cattle activities, in fruit growing and in wine production. The railroad arrived to San Rafael, In 1903, making the commercialization of products with Buenos Aires stronger. By a Provincial Ordinance dating 7th of October 1922 San Rafael's was declared a city. From then on, San Rafael grew in the agricultural environment, with important orchards. There were some problems, like the Descabezado Volcano eruption in April 1932, damaging the economy in the area. In the ´80s, the weather inclemency produced a fall in the agricultural activity and a rise in adventure tourism. The era of the tourism started as an alternative production to take advantage of the natural resources that San Rafael' offers. In that way it became a tourism resort in Mendoza Province.