Hetch Hetchy to Lake Vernon Trail, Mountain hiking trail in Yosemite National Park, United States.

The Hetch Hetchy to Lake Vernon Trail runs 11.5 miles one way from the parking lot by O'Shaughnessy Dam at Hetch Hetchy Reservoir to Lake Vernon in the Yosemite Wilderness, gaining 2,700 feet. The route climbs to 4,707 feet, with 3,723 feet of ascent on the way in and 984 feet on the way out.

The trail starts at O'Shaughnessy Dam, completed in 1923 to create the Hetch Hetchy Reservoir, which provides water to the San Francisco Bay Area. This construction shaped the valley landscape that hikers see on the route today.

The trail crosses the Yosemite Wilderness, where overnight stays require a wilderness permit from the Hetch Hetchy ranger station or an online reservation. The route ends at Lake Vernon, a backcountry lake reached after 11.5 miles one way from the O'Shaughnessy Dam parking lot.

Overnight hikers need to obtain permits and carry bear canisters because black bears actively search for food in the area. Starting early in the day allows time to reach camp before dark, and weather can change quickly at higher elevations.

This area sits at lower elevations than many other Yosemite routes, allowing spring access several months before higher altitude trails become passable. Hikers often discover unexpected views of the reservoir and surrounding peaks that feel remote despite proximity to popular valleys.