Sierra Nevada

Lone Pine Lake, in the Owen Valley, California. It is situated beneath Mount Whitney and the peaks of the Sierra Nevada can be seen all around.

Mountain range in eastern California, USA, extending for about 640 km/400 mi, with a general ridge line at over 2,500 m/8,202 ft. Its highest point is Mount Whitney, which rises to 4,418 m/14,494 ft. The Sierra Nevada includes the King's Canyon, Yosemite, and Sequoia national parks.

The range forms the eastern wall of the Central Valley of California, separating the state from the Great Basin and the rest of the continent. A small portion runs into Nevada, near Lake Tahoe. There are no easy passes, and the mountains formed a formidable barrier to early travel; the Donner Pass, which carries the main road and rail routes, lies at 2,150 m/7,050 ft. The mountains are heavily forested, and groves of giant sequoias grow on the western slopes. In 1848 settlers found gold in the western foothills, touching off the great 1849 gold rush. Silver mines have been opened on its eastern side.

The western flanks of the Sierra are scored by some of America's deepest valleys, partially carved by ice, and include Yosemite Valley and King's Canyon. In the southeast part of the range, the western side is known as the High Sierra. The eastern face is faulted and very steep. Its incline provides one of the most rapid natural transitions in North America, from snow-covered peak, through dense forest, to scrub, and down to desert; the lowest point on the continent, Death Valley, lies just over 100 km/60 mi east of Mount Whitney.

The Sierra Nevada is the southern part of a chain of mountains bordering the Pacific coast; the northern section is formed by the Cascade Range. Lassen Peak, which reaches 3,186 m/10,452 ft in northern California, is considered the dividing point between the two ranges; the southernmost end of the Sierra Nevada is bounded by the Tehachapi Pass.

Geology The mountains are part of the Cordilleran Belt, and were created by a single block of the earth's crust, which tilted upwards towards the east during the mid-Tertiary and later periods. It is mainly composed of igneous rock, predominantly granite, and metamorphic slate. Minerals include gold, formed within quartz, and silver.

The Sierra Nevada Ecosystem Project reported in 1996, in an attempt to develop better management systems for the mountains' environment.