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
Siskiyou Mountains 1910, pears had begun to replace apples as the major fruit grown in the region. In 1927, the Jackson County seat moved to Medford, which had become much larger than Jacksonville. The highest peaks in the range include Mount Ashland at an elevation of , Dutchman Peak at , Siskiyou Peak at , and Wagner Butte at , all of which are in Oregon. The highest peak in the California portion of the range is Preston Peak at . There are also several lower mountains, including Negro Ben Mountain, which reaches . The main drainage basins in the mountains are