Yosemite: An Introduction
Hetch Hetchy Reservoir, a source of drinking water for San Francisco, has spectacular scenery and is the starting point for trips along many backcountry trails. Visitors can walk along the top of O'Shaughnessy Dam and see cliffs and waterfalls. Hetch Hetchy Reservoir is located 40 miles (64km) from Yosemite Valley via Highway 120 and the Evergreen and Hetch Hetchy Roads. The top of the dam is at an elevation (altitude) of 3,800 feet (1160m) above sea level. The road is sometimes closed due to snow in winter, and vehicles of length over 25 feet are prohibited at all times.
Camping at Hetch Hetchy is limited to a backpackers' campground; a wilderness permit is required. See Yosemite Wilderness for information about wilderness travel. Lodging near Hetch Hetchy is available outside Yosemite National Park's borders.
Visitor activities, facilities, and services are described in the Yosemite Guide and Yosemite: Your Complete Guide to the Park. The National Park Service has a map of Yosemite National Park on its Web site.
Continue your introduction to Yosemite National Park: