Fully one-half of its length is through the mountainous districts of central Bolivia, where it is fed by a large number of rivers and streams from the snowclad peaks, and may be described as a raging torrent.
During the coldest winter months their communications are much easier with Spain than through the snowclad passes leading into Ariege.
Above sea-level; and its climate is cold and unpleasant, owing to the winds from the neighbouring snowclad heights, and the barren, pumicecovered table-land on which it stands.
Overlooking the plateau from the west are the snowclad peaks of Pomarape (20,505 ft.), Parinacota (20,918 ft.), Sajama (21,047), Huallatiri (21,654), Lirima (19,128), and the three volcanic peaks, Oyahua (19,226), San Pedro y Pablo (19,423) and Licancaur (19,685).
Above these are cool, temperate slopes and valleys, and high above these, bleak, wind-swept passes and snowclad peaks.