Yosemite National Park is a national park in California. It is bordered on the southeast by Sierra National Forest and on the northwest by Stanislaus National Forest. The park is managed by the National Park Service and covers 759,620 acres in four counties – centered in Tuolumne and Mariposa, extending north and east to Mono and south to Madera.
Designated a World Heritage Site in 1984, Yosemite is internationally recognized for its cliffs, waterfalls, clear streams, giant sequoia groves, lakes, mountains, meadows, glaciers, and biological diversity. Almost 95 percent of the park is designated wilderness. Yosemite is one of the largest and least fragmented habitat blocks in the Sierra Nevada.Its geology is characterized by granite and remnants of older rock. About 10 million years ago, the Sierra Nevada was uplifted and tilted to form its unique slopes, which increased the steepness of stream and river beds, forming deep, narrow canyons. About one million years ago glaciers formed at higher elevations. They eventually melted and moved downslope, cutting and sculpting the U-shaped Yosemite valley.European American settlers first entered the valley in 1851.