History of the Yosemite area drainages of two river watersheds. Preservation of watersheds was very important to Muir, who said "you cannot save Yosemite Valley without saving its Sierran fountains." The State of California retained control of Yosemite Valley and the Mariposa Grove of Big Trees. Muir and 181 others founded the Sierra Club in 1892, in part to lobby for the transfer of the valley and the grove into the national park. Like Yellowstone National Park before it, Yosemite National Park was at first administered by various units of the United States Army. Captain Abram Wood led the 4th Cavalry Regiment into the new
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