YOSEMITE, the name given to a beautiful valley and its picturesque environs in east-central California on the west slope of the Sierra Nevada mountains almost 150 m. due E. from San Francisco. It embraces 1,125 sq.m. of magnificent mountain scenery, of which the valley is the crowning glory. The park ex tends from the cold alpine granite crags and humble storm-torn pines of the Mt. Lyell crests of the Sierra Nevada divide, 13,090 ft. above sea level, westward 3o m. or more down the slope to the mild forest-clad valley-floors where stand the giant sequoias, towering sugar pines, superb yellow pines and stalwart Douglas firs, only 2,00o ft. above the sea.
The picturesque country north of the valley was occupied from early times by trappers; but the valley itself was unknown to the white man until March 21, 1851, when a Captain Boling of the Mariposa battalion pursuing Tenaya, chieftain of the Yosemite (Indian word meaning "grizzly bear") Indians, and his warriors, entered the majestic valley which was their stronghold. On his return he gave a vivid account of the wonderful place.
By 1865 the valley had become so well known and so popular that Congress granted it to the State of California as a reservation with the agreement that the State should use all income from it in building a road into it and improving the reservation. The Mari posa big tree grove, discovered by Galen Clark in 1857, was granted to the State at the same time. California kept faith, and in a few years the Yosemite became world famous. In 1890 Yosemite National Park was established, and in March 1905, California re-ceded the valley to the National Government.
Climate.—The climate of the park is unusually mild for its altitude, and from June to October little rain falls. In late October or early November the heavier rains begin, soon changing to snows which fill the valleys and drift about the slopes so that for months at a time travel is well-nigh impossible over most of the trails. The annual precipitation in the park ranges from 3o in. in the valley to 55 in. at an elevation of 5,000 feet. Over practically
the whole park except a few of the lowest slopes and valleys the precipitation is adequate for forest growth. The average annual snowfall at Yosemite over a period of 16 years was 110.7 in. begin ning in October and ending in May; the maximum recorded for Tamarack was in the winter of 1906-07 when the snowfall attained 884 in., or about 75 feet. The snow which sometimes accumulates to a depth of 3o or 4o ft. melts slowly in spring and early summer. In the summer months terrifying thunderstorms with destructive lightning are frequent, though yielding little rain.
Flora and Fauna.—The flora of the park is rich and varied, illustrating by the changes in character and species with elevation the effect of altitude. The lower slopes and valleys of the park lie in the main timber belt where yellow pine (hints ponderosa), sugar pine (Pinus Lambertiana), incense cedar (Libocedrus de currens), white fir (Abies concolor), Douglas fir (Pseudotsuga mucronata), some black oak (Quercus Kelloggii) and the big tree (Sequoia gigantea) are the conspicuous or dominant species; the middle slopes lie in the upper portion of the main timber belt where red fir (Abies magnifica), tamarack pine (Pinus contorta), and Jeffrey pine (Pinus Jeffery° come in; the upper slopes and knobs lie in the timber-line belt of Sierra juniper (Juniperus occi dentalis), mountain hemlock (Psuga Mertensiana), white-bark pine (Pinus albicaulis), f oxtail pine (Pinus Balfouriana) and tam arack pine; and the uppermost peaks and crests lie above timber line where willows and dwarf junipers and pines but a few inches high creep close to sheltering ledges and boulders, with arctic and alpine grasses and flowers struggling to mature their seed in the crevices of the cold gray granite. Gaily coloured flowers burst into bloom on all but the very highest crests during the mild sum mer months, making the alpine meadows and mountain woodlands a continuous garden of bloom. The rare flame-red spike of the beauteous snowplant rises above the meadows of the park like a glowing torch.