Brief SynthesisYosemite National Park vividly illustrates the effects of glacial erosion of granitic bedrock, creating geologic features that are unique in the world. Designated by the U.S. Congress in 1890 as a national park, Yosemite National Park is managed under the authority of the Organic Act of August 25, 1916 which established the United States National Park Service. In addition, the park has specific enabling legislation which provides broad congressional direction regarding the primary purposes of the park. In addition, the National Park Service has established Management Policies which provide broader direction for all National Park Service units, including Yosemite. The national park has a large and well-trained staff and works closely with other land and water management agencies in the larger Sierra Nevada region to protect shared resources.