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 destroyed nearly $2 billion in assets and revenue, though natural woodland assets are renewable, and closed off much of the park to tourists. This fire was the third largest on record, and burned nearly 500 acres of wild habitat. During late July and early August, 2018, sections of the park, including the Valley, were temporarily closed due to the Ferguson Fire at its western boundary. The closing was the largest in almost thirty years at the park. Yosemite Valley is open year-round and numerous activities are available through the National Park Service, Yosemite Conservancy, and Aramark at Yosemite, including nature