California’s snowy sawblade rose less than five million years ago
The Sierra Nevada runs about 400 miles between California’s Central Valley and the Great Basin, mostly in California save Nevada’s Carson Range spur. Mount Whitney at 14,505 feet tops the contiguous United States; Lake Tahoe is North America’s largest alpine lake; General Sherman is the world’s largest tree by volume.
Its granite crystallised deep underground during the Nevadan orogeny more than 100 million years ago; uplift less than five million years old, followed by glaciers, stripped the rock into pale cliffs. The name joins Spanish sierra, saw, with nevada, snowy. Cabrillo used it loosely in 1542, and Pedro Font fixed it on this range in his 1776 map. Gold Rush miners crowded the western foothills from 1848 to 1855, yet rugged access meant the high country was not fully explored until 1912.
Locals often scold anyone who says the Sierras, though the plural has history, as in Joaquin Miller’s 1871 Songs of the Sierras. Ansel Adams, seeing his photographs printed as views of the High Sierras, called the added s a linguistic, Californian and mountaineering sin.
From about 500 feet on the Central Valley floor the land climbs gradually to crest peaks above 14,000 feet some 50 to 75 miles east, then plunges down the steep Sierra Escarpment. Rising air wrings out heavy snow and rain the surrounding lowlands never see. The irregular northern edge, between the Susan River, Fredonyer Pass and the North Fork Feather River, is where the granite slips beneath younger volcanic rock of the Cascades; the Basin and Range lies east, the Mojave south-east, and Tehachapi Pass closes the south.
Western slopes drain to the Pacific at San Francisco. The northern third feeds the Sacramento through the Feather, Yuba and American rivers, and the middle third feeds the San Joaquin through the Mokelumne, Stanislaus, Tuolumne and Merced. The southern third sends the Kings, Kaweah, Tule and Kern into the closed Tulare Lake basin, which spills into the San Joaquin only in rare wet years.
Source: Sierra Nevada
