Yosemite National Park

Yosemite National Park has a wide variety of habitats as well as geological features.

In the lower, western elevations there is some grassland and chaparral which is replaced, at a slightly higher elevation, by a foothill woodland with blue oak, Quercus douglasii, and gray pine, Pinus sabiniana. Higher, is a mixed evergreen forest with ponderosa pine, Pinus ponderosa, incense cedar, Calocedrus decurrens, black and canyon live oaks, Quercus kelloggii and Quercus chrysolepis, and white fir, Abies concolor.

At around 1,800 meters (6,000 feet) the montane coniferous forests begin. Red fir, Abies magnifica, lodgepole, Western white, sugar and Jeffrey pines, Pinus contorta ssp. murrayana, Pinus monticola, Pinus lambertiana and Pinus jeffreyi, range up to about 2,440 meters (8,000 feet) where lodgepole pine and mountain hemlock, Tsuga mertensiana, become the dominant trees.

There are a number of alpine fell fields, alpine, subalpine and montane meadows and, along the watercourses, riparian associations. Much of the Park consists of barren or sparsely vegetated rock.

Three groves of sequoias, Sequoiadendron giganteum, occur in the Park; the southernmost, the Mariposa grove, is approximately 30 kilometers (19 miles) southeast of the others and about 8 kilometers (5 miles) north of the Nelder Grove.

Eight rare or uncommon plants are found in the Park; Allium yosemitense, Castilleja lemmonii, Carex whitneyi, Erigeron aequifolius, Lewisia disepala, Phalacroseris bolanderi, Trifolium bolandari and Triteleia dudleyi.

Animal life is abundant and varied. Over 200 species of birds and 78 species of mammals have been observed in the Park. Black bear, Ursus americanus, are common here.

All but a small portion of the Park is composed of Mesozoic granitics. Along the eastern edge of the Park there are Paleozoic marine sedimentaries and metavolcanics and Mesozoic metavolcanics. Several isolated Pliocene volcanic flows occur within the Park.

Yosemite Valley and the Grand Canyon of the Tuolumne are classic U-shaped valleys formed by glaciation which began some 2,000,000+/- years ago and continued intermittently to some 10,000 years ago. The Tuolumne glacier was the longest, 96 kilometers (60 miles), in the Sierra and terminated at about 600 meters (2,000 feet). At its maximum, the Merced (Yosemite) glacier was 40 kilometers (25 miles) long. It gouged some 600 meters (2,000 feet) of granite from the valley floor and, at its maximum, was some 1,800 meters (6,000 feet) thick. Between advances, lakes occurred in the valley, the latest existing between approximately 40,000 and 10,000 B.P. Glacial features are numerous, though no glaciers are found in the Park today. (Several occur immediately to the east.)

See also Merced River Natural Area, Tamarack Creek Natural Area and Carl Inn Natural Area.

Integrity: Portions have been protected since 1864, the present Park since 1890-1905. Portions are being impacted by overuse.

Use: Present

March 1980