In 1562, an encomienda was established to make the most docile Indians work. The abundance of silver mines in the surrounding areas made this region into an outstanding circulation and provisions place between Mendoza and Chile. Since the end of the 17th century and during the 18th century the area was characterized for mine working and the melting of the minerals performed by the Indians, who were organized by religious people who were in charge of catechizing them. Politically, during most part of this period, Mendoza, as the rest of Cuyo area, was part of the jurisdiction of the General Captaincy of Chile, which depended on the Viceroyalty of Perú. In 1776, when the Viceroyalty of the Río de la Plata was founded, Cuyo became part of the new structure, and the mountain range was set as a political border between Chile and Argentina. Uspallata Valley kept the same strategic value.