Located in the lesser-visited northwest corner of Yosemite National Park, Hetch Hetchy is a beautiful valley surrounded by tall granite walls that was dammed in the early 1900s to serve as a stable water source for the San Francisco Bay Area. Despite the controversy behind O'Shaughnessy Dam, hikers can still drive in and park fairly close to the dam and hike around the northern side of the reservoir to enjoy the sites of what is now a mostly underwater Grand Canyon of the Tuolumne River. Hiking to the base of Wapama Falls makes for a pleasant and moderately strenuous day hike.
If you want to drive to Hetch Hetchy Reservoir from Yosemite Valley, you may be surprised that it's a 40-mile (1.5 hour) drive. Take Big Oak Flat Road (Route 120) out of the park. Roughly one mile past the Big Oak Flat Entrance Station, turn right onto Evergreen Road and follow it north roughly 8.3 miles through the town of Mather to the Hetch Hetchy Entrance Station. From the entrance station, it's another 7.2 miles to the end of the Hetch Hetchy Road near O'Shaughnessy Dam. (If you are driving from Groveland, just east of Colfax Spring, take Cherry Lake Road north. Signs will point the way to Mather and Hetch Hetchy.)
|Moderately strenuous day hike
|O'Shaughnessy Dam at the end of Hetch Hetchy Road
|4.5 miles round-trip
|400-ft gradual ascent and descent
|Spring through autumn. (Hetch Hetchy Road is open all year, but conditions may be unpredictible in winter; be prepared for snow.)
At the end of Hetch Hetchy Road is a one-way loop with two parking areas and some roadside parking spots. In the summer, finding parking can get difficult, so arrive early or be prepared to walk the road quite a bit. Once you find your way to O'Shaughnessy Dam, navigation for this hike is very easy. Cross over the top of the dam, hike through the tunnel, and follow the trail around the north side of the reservoir. While the trail doesn't have much elevation gain, there are several ups and downs.
Along the way, you will pass the trail junction to the Beehive and Laurel Lake and Tueeulala Falls, a seasonal waterfall that may involve navigating through some wet slabs of granite. And after roughly 2.2 miles of hiking, you will arrive at the impressive Wapama Falls with two sturdy hikers bridges at its base. Wapama Falls is most impressive in late winter and spring and you're likely to get wet from the spray. Casual hikers will want to turn around at this spot, but backpackers can continue on to Rancheria Falls, Tiltill Valley, and beyond...
This hike is a good excuse to visit Hetch Hetchy Valley, especially in the off-season or spring when the waterfalls are at their best. Summer can get a little hot and crowded for this one.