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
Seven Second Summits of at least 100 km to reach Mount Logan. In South America, Ojos del Salado involves a short scramble while Aconcagua is just a walk. Horrell acknowledged that Ojos del Salado was more technically difficult, but considered Aconcagua a greater challenge because of physical demands. Aconcagua's base camp, at 4,500 m, is accessible by mule, but from that point, climbers must carry all of their supplies to as many as three higher camps before the final ascent. By contrast, Ojos del Salado is accessible by four-wheel-drive vehicles to 5,200 m; from that point, climbers need only carry supplies to a