Yosemite National Park ( ) is a
United States National Park spanning eastern portions of
Tuolumne,
Mariposa and
Madera counties in the central eastern portion of the
U.S. state of
California, commonly considered part of
Northern California. The park, which is managed by the National Park Service, covers an area of and reaches across the western slopes of the
Sierra Nevada mountain chain. About 3.8 million people visit Yosemite each year: most spend the majority of their time in the seven square miles (18 km
2) of
Yosemite Valley. Designated a
World Heritage Site in 1984, Yosemite is internationally recognized for its spectacular
granite cliffs,
waterfalls, clear
streams,
giant sequoia groves, and
biological diversity. Almost 95% of the park is designated
wilderness. Yosemite was central to the development of the national park idea. First,
Galen Clark and others lobbied to protect Yosemite Valley from development, ultimately leading to President
Abraham Lincoln's signing the
Yosemite Grant in 1864. Later,
John Muir led a successful movement to establish a larger national park encompassing not just the valley, but surrounding mountains and forests as well—paving the way for the United States national park system.