Yosemite National Park is a national park in California. It is bordered on the southeast by Sierra National Forest and on the northwest by Stanislaus National Forest. The park is managed by the National Park Service and covers 759,620 acres in four counties – centered in Tuolumne and Mariposa, extending north and east to Mono and south to Madera. Designated a World Heritage Site in 1984, Yosemite is internationally recognized for its granite cliffs, waterfalls, clear streams, giant sequoia groves, lakes, mountains, meadows, glaciers, and biological diversity. Almost 95 percent of the park is designated wilderness. Yosemite is one of the largest and least fragmented habitat blocks in the Sierra Nevada.
The Sierra Nevada is a mountain range in the Western United States, between the Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies primarily in Nevada. The Sierra Nevada is part of the American Cordillera, an almost continuous chain of mountain ranges that forms the western "backbone" of the Americas.
Tuolumne Meadows is a gentle, dome-studded, sub-alpine meadow area along the Tuolumne River in the eastern section of Yosemite National Park in the United States. Its approximate location is 37°52.5′N119°21′W. Its approximate elevation is 8,619 feet (2,627 m). The term Tuolumne Meadows is also often used to describe a large portion of the Yosemite high country around the meadows, especially in context of rock climbing.
Hetch Hetchy is a valley, a reservoir, and a water system in California in the United States. The glacial Hetch Hetchy Valley lies in the northwestern part of Yosemite National Park and is drained by the Tuolumne River. For thousands of years before the arrival of settlers from the United States in the 1850s, the valley was inhabited by Native Americans who practiced subsistence hunting-gathering. During the late 19th century, the valley was renowned for its natural beauty – often compared to that of Yosemite Valley – but also targeted for the development of water supply for irrigation and municipal interests. The controversy over damming Hetch Hetchy became mired in the political issues of the day. The law authorizing the dam passed Congress on December 7, 1913. In 1923, the O'Shaughnessy Dam was completed on the Tuolumne River, flooding the entire valley under the Hetch Hetchy Reservoir. The dam and reservoir are the centerpiece of the Hetch Hetchy Project, which in 1934 began to deliver water 167 miles (269 km) west to San Francisco and its client municipalities in the greater San Francisco Bay Area.
The exposed geology of the Yosemite area includes primarily granitic rocks with some older metamorphic rock. The first rocks were laid down in Precambrian times, when the area around Yosemite National Park was on the edge of a very young North American continent. The sediment that formed the area first settled in the waters of a shallow sea, and compressive forces from a subduction zone in the mid-Paleozoic fused the seabed rocks and sediments, appending them to the continent. Heat generated from the subduction created island arcs of volcanoes that were also thrust into the area of the park. In time, the igneous and sedimentary rocks of the area were later heavily metamorphosed.
The Tuolumne River flows for 149 miles (240 km) through Central California, from the high Sierra Nevada to join the San Joaquin River in the Central Valley. Originating at over 8,000 feet (2,400 m) above sea level in Yosemite National Park, the Tuolumne drains a rugged watershed of 1,958 square miles (5,070 km2), carving a series of canyons through the western slope of the Sierra. While the upper Tuolumne is a fast-flowing mountain stream, the lower river crosses a broad, fertile and extensively cultivated alluvial plain. Like most other central California rivers, the Tuolumne is dammed multiple times for irrigation and the generation of hydroelectricity.
The Raker Act was an act of the United States Congress that permitted building of the O'Shaughnessy Dam and flooding of Hetch Hetchy Valley in Yosemite National Park, California. It is named for John E. Raker, its chief sponsor. The Act, passed by Congress in 1913 by the Wilson administration, specified that because the source of the water and power was on public land, no private profit could be derived from the development. The plan for damming the valley was fought for years by John Muir. Construction of the dam was finished in 1923.
Wapama Falls is the larger of two waterfalls located on the northern wall of Hetch Hetchy Valley below Hetch Hetchy Dome, in Yosemite National Park. It flows almost year-round and during peak flow has been known to inundate the trail bridge crossing its base, making the falls impossible to pass. The falls consist of two primary drops angled roughly 60 degrees to each other, and a broad cascade at its base.
Cherry Creek is a large, swift-flowing stream in the Sierra Nevada mountain range, and is the largest tributary of the Tuolumne River. The creek is 40 miles (64 km) long measured to its farthest headwaters; the main stem itself is 26 miles (42 km) long, draining a watershed of 234 square miles (610 km2) in the Stanislaus National Forest. Part of the drainage also extends into the northwest corner of Yosemite National Park.
William Edward Colby was an American lawyer, conservationist, and first Secretary of the Sierra Club.
The Hetch Hetchy Railroad (HHRR) was a 68-mile (109 km) standard gauge Class III railroad constructed by the City of San Francisco to support the construction and expansion of the O'Shaughnessy Dam across Hetch Hetchy Valley.
Yosemite National Park is located in the central Sierra Nevada of California. Three wilderness areas are adjacent to Yosemite: the Ansel Adams Wilderness to the southeast, the Hoover Wilderness to the northeast, and the Emigrant Wilderness to the north.
Kolana Rock is a prominent granite dome located along the southern edge of Hetch Hetchy Valley in Yosemite National Park. John Muir stated that Kolana was the Indian name for the rock. It towers 2,000 feet (610 m) above the Hetch Hetchy Reservoir, and is across from Hetch Hetchy Dome.
Falls Creek, also known as the Falls River, is a tributary of the Tuolumne River in Yosemite National Park, California, United States. The creek begins at the northern boundary of the national park and flows 24 miles (39 km) to empty into the Tuolumne at Hetch Hetchy Reservoir, dropping over two well-known waterfalls. The Pacific Crest Trail and other national park trails follow the creek for much of its course.
Restore Hetch Hetchy is a US non-profit organization seeking to restore the Hetch Hetchy Valley in Yosemite National Park to its original condition.
O'Shaughnessy Dam is a 430-foot (131 m) high concrete arch-gravity dam in Tuolumne County, California, United States. It impounds the Tuolumne River, forming the Hetch Hetchy Reservoir at the lower end of Hetch Hetchy Valley in Yosemite National Park, about 160 miles (260 km) east of San Francisco. The dam and reservoir are the source for the Hetch Hetchy Aqueduct, which provides water for over two million people in San Francisco and other municipalities of the west Bay Area. The dam is named for engineer Michael O'Shaughnessy, who oversaw its construction.
Piute Creek is a 19-mile (31 km) long stream in northern Yosemite National Park, in Tuolumne County, California. It is a major tributary of the Tuolumne River, draining a rugged and remote area of the Sierra Nevada.
Rancheria Creek is a 22-mile (35 km) long stream in northern Yosemite National Park mostly in Tuolumne County, California and is a tributary of the Tuolumne River. Draining a large area of the Sierra Nevada, it is the largest tributary of the Tuolumne within Yosemite National Park. The stream is labeled as Kerrick Creek on some early maps.
