The New International Encyclopædia/Sierra Nevada (California)

SIERRA NEVADA,. A mountain range in eastern California, forming the divide between the Great American Basin and the valley of the Sacramento and San Joaquin rivers (Map:, D 3). It is a tilted plateau 80 miles wide and extending in a north-northwest direction, 400 or 500 miles according as the range is considered to end at Lassen Peak or at the northern State boundary. In the south it turns westward and merges with the Coast Range, and in the north it is continued into Oregon as the Cascade Mountains. It consists of a granitic core exposed in the higher portions, flanked by metamorphic slates, and in the lower western slopes by later marine deposits ranging from Carboniferous to Cretaceous. North of Lassen Peak, in the northern part of the State, these formations disappear under the great Oregon lava flow, so that here the Cascade Mountains may be said to begin, although the name Sierra Nevada is often extended up to the State boundary so as to include Mount Shasta. The average elevation of the crest is 10,000 feet in the southern half and somewhat less in the north. The range falls abruptly on the east to the valley floor of the Great Basin, 5000 feet below, while on the west it has a wider and more gradual slope. The Sierra Nevada, whose greatest elevation but slightly exceeds that of the Rocky Mountains, appears much more massive and impressive than the latter range, as it rises from a much lower level. The number of peaks, however, is not as great as in Colorado, though there are at least 14 peaks over 12,000 feet high. The highest peaks are clustered near the southern end, and here Mount Whitney, the highest point in the United States proper, attains an altitude of 14,898 feet. Other high points are Fisherman Peak, 14,448 feet; Mount Corcoran, 14,093 feet; Mount Kaweah, 14,000 feet; Mount Brewer, 13,886 feet; Mount Lyell, in the Yosemite Park, 13,042 feet; and iii the extreme north Mount Shasta, with an altitude of 14,380 feet. The higher portions of the range are covered with perpetual snow, and the northern slopes of some of the peaks are occupied by glaciers. The snowfall is heavy on the western slope, and feeds a large number of streams flowing to the Sacramento and San Joaquin Rivers. These streams have cut up the slope into deep valleys, some of which, notably

the Yosemite Valley, are remarkable for their scenery. The Sierra Nevada is covered to a height of 8000 feet with dense forests of coniferous trees, which yield to deciduous on the lower western slope. The western slope, above the deciduous zone, is the exclusive habitat of the ‘big trees’ (Sequoia gigantea). Though it is a practically unbroken divide, there are several passes leading across the range at altitudes of 4000 to 7000 feet. Of these the Truckee Pass in the north and the Tehachapi Pass in the south are traversed by railroads.