History of the Yosemite area the Yosemite area in 1863. Pressure from Starr King and Olmsted, photographs by Carleton Watkins, and geological data from the 1863 Geological Survey of California prompted legislators to take action. Senator John Conness of California introduced a park bill in 1864 to the United States Senate to cede Yosemite Valley and the Mariposa Grove of Big Trees to California. The bill easily passed both houses of the United States Congress, and was signed by President Abraham Lincoln on June 30, 1864. The Yosemite Grant, as it was called, was given to California as a state park for "public use, resort
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