160-mile stretch the lowest pass is at an altitude of 9,000 feet, while Kearsage, the most frequently used pack horse pass on this stretch, is 12,050 feet; in this area the peaks range from 13,000 to 14,000 feet in height. Although there is a gradual decline in altitude to the north, other isolated peaks of the Sierra rise above 14,000 feet. Northward the western slopes are gashed by river canyons sometimes half a mile deep.
The Sierra's sculptured splendor is in part the work of glaciers which carved deep valleys, expanses of polished rock, and towering granite walls over which roar great waterfalls, glacial lakes and meadows. Most beautiful of the valleys is Yosemite, in the midsection of the Sierra; loveliest of the lakes is Tahoe (6,225 alt.), cupped between the main Sierra and the basin ranges at the angle of the Nevada-California boundary. A few glaciers even now survive on the highest summits, the finest of them being a group of five supported by Mount Shasta (14,161 alt.).
Dominating the northern end of the Sacramento Valley is Mount Shasta, the most striking of the many extinct or dormant volcanoes in the northern California mountains. Lassen Peak (10,435 alt.), 85 miles southeast of Mount Shasta, is a mildly active volcano—the only one in the United States that has had a generally observed eruption. Although traces of volcanic action are most abundant in the State's northeastern sector, where lava beds spread over vast tracts, there are also extinct or dormant volcanoes in Owens Valley and the Mojave Desert, and numerous hot springs in the Coast Range.
The Coast Range, more complex than the Sierra, includes numerous indistinct chains from 2,000 to 7,000 feet high. Each chain is broken down into forested spurs and ridges enclosing small pleasant valleys and plains drained by rapid streams.
The Santa Ynez, San Barnardino, and San Gabriel Mountains bound the lowland of southern California on the north and northeast, and subdivide it into more or less distinct valleys or basins. Farther south the coastal lowland is bounded by the Santa Ana and San Jacinto Ranges, an elevation that extends into Mexico. The southern California ranges are marked by the lofty peaks (more than 10,000 feet high) of San Bernardino, San Jacinto, and San Antonio and by the well-defined passes of Soledad, Cajon, and San Gorgonio.
Among the mountain-walled valleys between the southern end of the Sierra and the border of Nevada is the long and narrow Owens Valley, bordered by granite walls. About 40 miles east of dry Owens Lake, along the California-Nevada border, lies Death Valley, its lowest point 276 feet below sea level. It stretches between the sheer rocky walls of the Panamint Range on the east and the Amargosa Range on the west 130 miles long and from 6 to 14 miles wide—a region of stark simplicity, majestic silence, and spectacular desolation. South
