Geology of Chile the Taitao Peninsula, the Peru–Chile Trench subduction zone is the boundary between the South American and Nazca Plates. At Taitao, the Chile Triple Junction and the Nazca Plate subduct the South American Plate. In Norte Grande the mountains form a series of plateaus, such as Puna de Atacama and the Altiplano. At a south latitude of 27 degrees, Chile's highest mountain (Ojos del Salado) reaches a height of . Below 42 degrees south, the Andes split into a fjord landscape and the highest mountain is Monte San Lorenzo at . As the mountains ebb, the snow line lowers; in the
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