Yosemite National Park and ponds, of streams, of hiking trails, and of roads. Two federally designated Wild and Scenic Rivers, the Merced and the Tuolumne, begin within Yosemite's borders and flow westward through the Sierra foothills, into the Central Valley of California. On average, about 4 million people visit the park each year, with most visitor use concentrated in the seven-square-mile (18 km) area of Yosemite Valley. Almost all of the landforms in the Yosemite area are cut from the granitic rock of the Sierra Nevada Batholith (a batholith is a large mass of intrusive igneous rock that formed deep below the surface).
Yosemite National Park trails in Yosemite Valley itself; mountain biking is not allowed. Rock climbing is an important part of Yosemite. Camp 4, a walk-in campground in Yosemite Valley, was instrumental in the development of rock climbing as a sport, and is listed on the National Register of Historic Places. Climbers can generally be spotted in the snow-free months on anything from ten-foot-high (3 m) boulders to the face of El Capitan. Classes on rock climbing are offered by numerous groups. Yosemite Valley is open all year, although some roads within the park close in winter. Downhill skiing is available at the Badger