Yosemite National Park is a protected area in the United States located within the Sierra Nevada mountains of east-central California. It spans approximately 1,187 square miles across four counties, primarily centered in Tuolumne and Mariposa, with extensions into Mono and Madera. The park is bordered by the Stanislaus National Forest to the northwest and the Sierra National Forest to the southeast. Managed by the National Park Service, it serves as a critical conservation zone for one of the largest and least fragmented habitat blocks in the region.

The area holds significant historical weight as the site of the first federal preservation of scenic land for public use. In 1864, President Abraham Lincoln signed the Yosemite Grant, protecting the valley from development. Later lobbying by environmentalist John Muir led to its designation as a national park in 1890. The region was designated a UNESCO World Heritage Site in 1984. Its history includes the displacement of the Ahwahneechee people and the Mariposa War, followed by periods of Native American eviction from the park boundaries in the twentieth century.

The landscape is defined by granite cliffs, domes, waterfalls, and U-shaped valleys sculpted by glaciers over a million years ago. The park contains thousands of lakes, extensive streams, and groves of giant sequoia trees. Visitors typically spend time in the seven-square-mile Yosemite Valley, which features towering rock formations and high mountain meadows. The geology results from uplifts that occurred ten million years ago, creating steep slopes and deep canyons that characterize the terrain today.

Yosemite attracts approximately four million visitors annually who come to view its natural wonders, including spectacular granite cliffs and remote wilderness. The park set a visitation record in 2016 with over five million guests, though numbers fluctuated to over four million in 2024. Cultural heritage is preserved through the Yosemite Museum and exhibits at the Smithsonian, highlighting the history of the indigenous Southern Sierra Miwuk Nation. The area remains a focal point for conservation debates, particularly regarding the Hetch Hetchy Valley.

The park covers 750,000 acres and includes 800 miles of hiking trails and 350 miles of roads for visitor access. It is situated in a mountainous region with a climate that supports diverse biological diversity and glacial remnants. The economy relies heavily on tourism, with most visitors focusing their activities within the central valley area. Access is facilitated by the extensive road network and trail systems that allow exploration of the park's varied ecosystems and historical sites throughout the year.