A Map and Guide to Hetch Hetchy Reservoir at Yosemite

If you’re near Yosemite and someone says Hetch Hetchy, they aren’t sneezing or hiccuping. Instead, they’re talking about a glacier-carved valley that naturalist John Muir once called a "remarkably exact counterpart” to the legendary Yosemite Valley.

Until 1913, waterfalls cascaded down towering cliffs into the valley below. Today, a lake fills the valley and waterfalls cascade directly into it. If you’re thinking about visiting Hetch Hetchy during your Yosemite vacation, these pros, cons, and views may help you decide whether to go.

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Guide to Visiting Hetch Hetchy

The area called Hetch Hetchy is mostly buried beneath a reservoir. It's about a half-hour drive from CA Highway 120. Hetch Hetchy is pretty and interesting, but it's not among the top sights at Yosemite. It's hardly worth the long drive to get there if your time is limited. If you're staying three to four days or making a repeat visit, it might make a good change of pace.

At the Hetch Hetchy Reservoir, you can walk across the dam and learn more about area's history from the interpretive signs. Because of its lower elevation, Hetch Hetchy has the park's longest hiking season in the area. You can walk on several trails, ranging from two to 13 miles long.

In spring, wildflowers bloom along the trails. Wapama Falls is easily seen from the dam. Fishing is allowed year-round at Hetch Hetchy, with a valid California fishing license. Pets are allowed in the parking area only, on a leash, but cannot go on the trails or the dam.

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O'Shaughnessy Dam

In 1913, for the only time in its history, the U.S. allowed a single city to appropriate part of a national park for its exclusive use. President Woodrow Wilson signed the Raker Act on December 19, 1913, which permitted San Francisco to build a dam in Hetch Hetchy Valley. When completed in 1923, the O'Shaughnessy Dam stood 364 feet high. It is named for the chief engineer of the Hetch Hetchy Project.

The lake stretches for about eight miles on the Tuolumne River and is a source of water for people who live in San Francisco, San Mateo, and Alameda Counties about 160 miles away. Hetch Hetchy is more than just a water reservoir. It's also the backbone of San Francisco's clean energy system, supplying hydroelectric power from four powerhouses.

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Wapama Falls

One of the most unique sites at Hetch Hetchy, Wapama Falls is a 1,300-foot-tall cascade that flows fastest in the spring when the snow melts. And it spills directly into the lake. Although it's not visible on a quick stop at the parking area and damTueeulala Falls also cascades directly into the lake.

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Getting to Hetch Hetchy: A Map

Map of Yosemite and Hetch Hetchy — Adapted from Google Maps

Yosemite National Park's Hetch Hetchy Valley and Reservoir are at about 3,800 feet elevation, on the east side of the park, about a mile east of the Big Oak Flat entrance to Yosemite. You can see where it is on this Yosemite map.

Getting There

To reach Hetch Hetchy, you have to exit Yosemite National Park and re-enter it. Take CA Highway 120 from the park toward Groveland. From the main road, it's about a 20- to 25-minute drive to the parking area.

The half-hour drive to Hetch Hetchy from CA Highway 120 begins outside the park boundaries. It passes Camp Mather, the construction camp for the O'Shaughnessy Dam, which — because the land is owned by the city — is now a San Francisco city park.

From there, the road follows the Tuolumne River, curving above the Poopenaut Valley to a parking area and wilderness campground. For a casual visit to Hetch Hetchy, allow about 1.5 hours to make the round trip from the main highway. Vehicles more than 25 feet long are prohibited on the narrow, somewhat winding road to Hetch Hetchy.

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Hetch Hetchy Valley Before Dam

painting of Hetchy Hetchy Valley by Albert Bierstadt — SuperStock/Getty Images

This painting by Albert Bierstadt — although probably idealized — gives you an idea of what the valley looked like before the dam, and how it might look if returned to its natural state.

The Fight to Preserve Hetch Hetchy

In 1870, naturalist John Muir called the Hetch Hetchy Valley "a wonderfully exact counterpart of the great Yosemite." When damming the Tuolumne River in Hetch Hetchy Valley was first proposed, it met vigorous opposition from Muir.

He has been quoted by the Sierra Club and others as saying: "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."

Muir and his allies fought a fierce battle, the last in Muir's life (he died in 1914), but they lost. Hetch Hetchy Lake drowned the valley. Even today, some oppose its presence and try to have it removed. .

A century later, the debate still rages. In 1987, Secretary of the Interior Donald Hodel proposed a plan to restore Hetch Hetchy Valley. The Sierra Club supports the continuing pressure to tear down the dam and restore the valley, and the organization Restore Hetch Hetchy has much information about current status, the truth about common myths and ways you can make your opinion heard.