Sierra Foothills Geography
The Sierra Nevada stretches from Fredonyer Pass in the north to Tehachapi Pass in the south. It is bounded on the west by California's Central Valley and on the east by the Basin and Range Province. Physiographically, the Sierra are a section of the Cascade-Sierra Mountains province, which in turn is part of the larger Pacific Mountain System physiographic division.
West-to-east, the Sierra Nevada elevation gradually increases from the California Central Valley to the crest, while the east slope forms the steep Sierra Escarpment. The Pacific Ocean watersheds of the west slope are the Sacramento River hydrologic subregion (north), the San Joaquin River subregion (central), and the endorheic Tulare-Buena Vista Lake subregion (south). The endorheic east slope is part of the Great Basin and has drainage water that is moved to the southern California coastal subregion by the Los Angeles Aqueduct.
The height of the mountains in the Sierra Nevada gradually increases from north to south. Between Fredonyer Pass and Lake Tahoe, the peaks range from 5,000 feet (1,500 m) to more than 9,000 feet (2,700 m). The crest near Lake Tahoe is roughly 9,000 feet (2,700 m) high, with several peaks approaching the height of Freel Peak [10,881 feet (3,317 m)]. Further south, the highest peak in Yosemite National Park is Mount Lyell [13,120 feet (3,999 m)]. The Sierra rise to almost 14,000 feet (4,300 m) with Mount Humphreys near Bishop, California. Finally, near Independence, Mount Whitney is at 14,505 feet (4,421 m), the highest point in the contiguous United States.
South of Mount Whitney, the range quickly dwindles. The crest elevation is almost 10,000 feet (3,000 m) near Lake Isabella, but south of the lake, the peaks reach only to a modest 8,000 feet (2,400 m).