Loa River
The Loa River (Spanish: Río Loa) is a U-shaped river in Chile's northern Antofagasta Region. At long, it is the country's longest river and the main watercourse in the Atacama Desert. Course The Loa's sources are located on Andean mountain slopes at the foot of Miño Volcano. The upper Loa basin is flanked on the west by a ridge with elevations that reach above , whereas to the east lies a volcanic chain, which separates it from endorheic basins as that of Salar de Ascotán. The river flows south on an elevated plateau, for about , to the oasis of Chiu Chiu. The upper courses of the river are at a considerable elevation above sea level and receive a large volume of water from the Andes, mainly of two major tributaries: San Pedro de Inacaliri River and Salado River. The former joins the Loa near Conchi reservoir and the latter about south of Chiu Chiu. The water of its upper course and tributaries is fresh. However the lower course, as in all the rivers of this region becomes brackish. From Chiu Chiu, the Loa flows west and north in a great curve to Quillagua. After flowing for in this portion