Cordillera the cordilleras in Ecuador, Peru, Bolivia, Chile, and Argentina. Mountain ranges of this type have a complex structure, usually the result of folding and faulting accompanied by volcanic activity. In South America the ranges include numerous volcanic peaks. (Though not itself a volcano, Argentina's Mt. Aconcagua, at 22,834 feet (6,960 metres) high, is the highest point in the Western Hemisphere. The Andes cordillera has Ojos del Salado, the highest active volcano in the world, and second highest point in the Western Hemisphere. A number of the volcanoes have been active in historic times. Aside from the volcanic peaks, the crests
Ojos del Salado of Ojos del Salado was , but that was "simply [...] based on the altitude of the final camp, and the hours of ascent to the summit." In 1956, the first Chilean expedition led by the retired lieutenant René Gajardo measured the height of Ojos del Salado as with a pocket pressure altimeter. Apart from being an inexact method, the height shown by the altimeter was far too high as air pressure is generally lower in the afternoon, the time at which the team reached the summit. An expedition to the area in the 1990s claimed that nearby Monte Pissis