Rastrillada de los chilenos or Camino de los chilenos (Spanish for road of the Chileans) were a group of routes in Patagonia used by Mapuches and related araucanized tribes to head cattle stolen during malones from Argentina to Chile across the Andes. Camino de los chilenos ran a length of about 1000 km from the Buenos Aires Province to the mountain passes of Neuquén Province. The cattle were traded in Chile for weapons and alcoholic beverages. This trade has been pointed out as the single most important cause of the war that affected the southern provinces of Argentina during large parts of the 19th century. Therefore the demand for cattle by Chilean merchants was fueling the conflict in Argentina. To counter the cattle raids a trench called Zanja de Alsina was built by Argentina in the pampas in the 1870s. The use of this trade route effectivelly ended with the Conquest of the Desert (1876-1878) carried out by the Argentine Army.