National Park Service the United States. In 1872, there was no state government to manage it, so the federal government assumed direct control. Yosemite National Park began as a state park; the land for the park was donated by the federal government to the state of California in 1864 for perpetual conservation. Yosemite was later returned to federal ownership. At first, each national park was managed independently, with varying degrees of success. In Yellowstone, the civilian staff was replaced by the U.S. Army in 1886. Due to the irregularities in managing these national treasures, Stephen Mather petitioned the federal government to improve the
Yosemite National Park the Sherwin (also called the pre-Tahoe), Tahoe, Tenaya, and Tioga. The Sherwin glaciers were the largest, filling Yosemite and other valleys, while later stages produced much smaller glaciers. A Sherwin-age glacier was almost surely responsible for the major excavation and shaping of Yosemite Valley and other canyons in the area. Glacial systems reached depths of up to and left their marks in the Yosemite area. The longest glacier in the Yosemite area ran down the Grand Canyon of the Tuolumne River for , passing well beyond Hetch Hetchy Valley. Merced Glacier flowed out of Yosemite Valley and into the Merced