Massive, ancient giant sequoias live in three groves in Yosemite National Park. The most easily accessible of these (spring through fall) is the Mariposa Grove near the park's South Entrance, off of the Wawona Road (Highway 41). Two smaller, and less visited, groves are the Tuolumne and Merced Groves near Crane Flat.
The Mariposa Grove, the largest of the three groves with over 500 Giant Sequoias, was closed for three years while a major restoration project was implemented. The grove re-opened to the public in June of 2018. You can learn about the restoration, and joint initiative between Yosemite National Park and the Yosemite Conservancy, here.
During the winter months when the road to Mariposa Grove is covered with snow, you can hike, snowshoe or cross country ski up the two-mile road to the lower grove (500 feet of elevation gain).
No roads enter the Tuolumne or Merced Groves; a moderate hike of 1 to 1.5 miles is required before you will see Giant Sequoias. Note: there is about 500 feet of elevation loss on your way to the groves so the return to the parking areas is uphill.
