Yosemite National Park, a unit of the National Park System of the United States. The park lies on the western slope of the Sierra Nevada range in east-central California, 150 miles (240 km) east of San Francisco. It covers 1,187 square miles (3,074 km2), an area nearly equal to that of Rhode Island. Yosemite's magnificent valleys and rock formations were carved largely by the grinding action of glaciers. Streams tumbling over the rock ledges create spectacular waterfalls. Yosemite is one of the most popular of the national parks, attracting several million visitors yearly.
The heart of the park is Yosemite Valley, which is about seven miles (11 km) long and one mile (1.6 km) wide. Between its towering granite walls flows the Merced River. Rimming the valley and rising 2,000 to 4,000 feet (600 to 1,200 m) above the valley floor are sheer rock walls, domes, and peaks. Among the prominent rock formations are El Capitan, Cathedral Rocks, Half Dome, and Three Brothers. Glacier Point, near the south rim, reaches 7,214 feet (2,199 m) and offers a magnificent view of the valley and the crest of the Sierra Nevada.
Yosemite has some of the world's highest waterfalls. Ribbon Falls has the longest single drop in the United States—1,612 feet (491 m). The three-tiered Yosemite Falls drops more than 2,400 feet (700 m). Other strikingly beautiful falls include Nevada and Bridalveil falls.
Most of the park is mountainous. The eastern part, called the high country, is the loftiest area. Found here is Mount Lyell, which reaches 13,114 feet (3,997 m); it is the highest point in the park. Elevations in the high country range from about 8,000 to 12,000 feet (2,400 to 3,700 m) above sea level. Tuolumne Meadows, about 55 miles (89 km) by road from Yosemite Valley, is a popular camping area and the starting point of hiking and camping trips into the high country. Yosemite is known not only for the grandeur of its landscape, but also for the giant sequoias that grow in Tuolumne, Merced, and Mariposa groves. Black oak, canyon live oak, ponderosa pine, and sugar pine are among the park's more common trees. Seasonal wildflowers add vivid color to the numerous meadows. Black bears, mule deer, coyotes, and many smaller mammals roam the less traveled parts of the park. More than 200 species of birds are found in Yosemite. Streams and mountain lakes support an abundance of fish.
There are four entrances to the park; the easternmost, Tioga Pass, is closed in winter. Most visitors stay in Yosemite Valley, where there are numerous camping and lodging facilities. Information about the park is provided by park naturalists, who give tours and lectures, and by several museums. Happy Isles Trail Center is the trailhead of the John Muir Trail, one of the most scenic of the park's many trails. The park offers skiing at Badger Pass ski center and on numerous cross-country trails.
Probably the first white men to enter Yosemite Valley were the members of the Mariposa Battalion, a state-appointed militia who arrived in 1851 to subdue the Ahwahneechee Indians who lived there. Later, visitors so praised the valley's beauty that President Lincoln in 1864 granted the valley and Mariposa Grove to California for public use. In the late 1870's John Muir, a naturalist, called public attention to the remarkable trees and geologic formations of Yosemite. His writings stirred countrywide enthusiasm, and in 1890 a national park was established encompassing the valley and surrounding area. Joint federal and state administration of the park ended in 1906, when California turned its lands back to the federal government.