... to conserve the scenery and the natural and historic objects and the wildlife therein and to provide for the enjoyment of the same in such manner and by such means as will leave them unimpaired.
National Park Service mission, by Act of Congress, 1916
Though not known to European Americans until 1851, the exceptional beauty and value of the Yosemite area was recognized immediately. In 1864 Abraham Lincoln signed an act creating a park, to be administered by the state of California. In 1890 the park was greatly expanded and passed back to federal ownership as Yosemite National Park.
The gem of the park is of course Yosemite Valley, but there are other treasures within its 1189 square miles (308,000 ha). Hetch Hetchy is in many ways a smaller version of Yosemite Valley. This panorama was taken at the base of thunderous Wapama Falls, 1,341 feet (409 m) high. Also in view is slender Tueelala Falls, 800 feet (244 m), and Kolana Rock towering 2000 feet (600 m) above the reservoir.
Water has exceptional value in California. It is abundant in the mountains, but scarce in the lowlands, where the crops and cities always need more. By the beginning of the 20th century both San Francisco and Los Angeles were looking far and wide for reliable supplies of water. Los Angeles eventually built a 223 mile (359 km) aqueduct down the east side of the Sierra Nevada, completed in 1913 (but not without controversy). San Francisco decided to build a 156 mile (251 km) pipeline from the Tuolumne River on the west slope of the Sierra.
The San Francisco proposal included building a dam to flood Hetch Hetchy Valley as a reservoir, for storage of the spring runoff and generation of electricity - entirely within Yosemite National Park.
Public outcry was immediate and the debate raged for years. John Muir marshaled the forces of the Sierra Club to fight the proposal. His famous quote was "Dam Hetch Hetchy! As well dam for water-tanks the people's cathedrals and churches, for no holier temple has ever been consecrated by the heart of man."
But money and political power finally won. In 1913 Congress passed the Raker Act authorizing the dam within the national park. It is often said that Muir died of sorrow over the loss. O'Shaughnessy Dam was completed in 1923.
For years the San Francisco water department has limited access to Hetch Hetchy - the road is closed at night, no swimming or boating is allowed and camping is severely limited. But awareness of the valley and its unique history is spreading, and a movement to remove the dam is gaining support. Muir's Sierra Club, now 115 years old and 750,000 strong, has vowed to see it done.
A few small dams have been removed here and there around the world. But never has a huge dam such as O'Shaughnessy - 430 feet (131 m) high - been deconstructed. It will take an act of Congress, and won't happen under a Republican administration.
But someday... Hetch Hetchy Valley may reappear from beneath the waters.
See the Sierra Club's Hetch Hetchy page