Yosemite National Park The State of California, however, retained control of Yosemite Valley and Mariposa Grove. Muir also helped persuade local officials to virtually eliminate grazing from the Yosemite high country. The newly created national park came under the jurisdiction of the United States Army's Troop I of the 4th Cavalry on May 19, 1891, which set up camp in Wawona with Captain Abram Epperson Wood as acting superintendent. By the late 1890s, sheep grazing was no longer a problem, and the Army made many other improvements. The cavalry could not intervene to ease the worsening condition of Yosemite Valley and Mariposa Grove.
Yosemite National Park visitors to Yosemite Valley. John Muir was a Scottish-born American naturalist and explorer. It was because of Muir that many National Parks were left untouched, such as Yosemite Valley National Park. One of the most significant camping trips Muir took was in 1903 with then president Theodore Roosevelt. This trip persuaded Roosevelt to return "Yosemite Valley and Mariposa Grove to federal protection as part of Yosemite National Park". John Muir wrote articles popularizing the area and increasing scientific interest in it. Muir was one of the first to theorize that the major landforms in Yosemite Valley were created by large