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 U.S. Congress authorized the O'Shaughnessy Dam through passage of the Raker Act. In the late 1920s a bid for Yosemite for the 1932 Winter Olympics was put forward. Ultimately, the 1932 Winter Olympics were awarded to Lake Placid, New York. In 1937, conservationist Rosalie Edge, head of the Emergency Conservation Committee (ECC), successfully lobbied Congress to purchase about 8,000 acres of old-growth sugar pines on the perimeter of Yosemite National Park that were to be logged. More recently, preservationists persuaded Congress to designate , or about 89% of the park, as the Yosemite Wilderness—a highly protected wilderness area. The Park