Flag Hill and Cerro Este

Sunol Regional Wilderness
Length 9.6 mi · Climbing 2260 ft
California > San Francisco Bay Area > Sunol Regional Wilderness
Backpack Road, Sunol Regional Wilderness

Backpack Road

Sunol is known for being a challenging park to hike, and this loop is no exception. The hike start out with some of the park’s best steepest climbs and best scenery on the Flag Hill and Vista Grande trails. The rest of the hike is easier and includes a visit to the park’s most popular feature, a rocky cascade known as Little Yosemite.

The trails are surprisingly popular given how remote and difficult they are; at peak times you can might pass a group every 5 or 10 minutes on most of the trails in this loop.

Driving into the park from the entrance kiosk, continue just past the turnoff to the visitors’ center parking lot and, if space is available, park under the trees next to the trailhead. On nice spring weekends you’ll probably need to park in the overflow lot a third of a mile further down the road, then walk back to the visitors’ center.

Begin the hike by walking across the footbridge across Alameda Creek. This is a pretty good-sized creek for this area; in winter it’s an impressive 30 foot wide torrent.

Turn left onto the trail, which meanders through the cool shady forest by the creek. Look for the Flag Hill Trail to your right and turn onto it.

Vista Grande Road, Sunol Regional Wilderness

Vista Grande Road

The trail immediately begins to climb, quickly leaving the dense creekside forest behind. The trail is narrow and very steep, but the way it winds through attractive oak-dotted meadows makes it especially engaging. There are some views of the valley floor, although at first the view is mostly of the parking lots. Eventually the trees end completely and the trail reaches the hilltop. A short path to your left leads to a viewpoint on top of Flag Hill.

Follow the dirt road to the right. The road descends the other side of the hill into High Valley. In spring the descent into the green valley with its barn and grazing cows is one of the scenic highlights of the hike, but in summer the treeless valley seems a little barren. Reaching High Valley Road, continue straight onto Vista Grande Road, beginning another punishing climb. The road rises and falls along the ridgetop, offering views mostly of High Valley but also of the hills to the north.

At the first intersection, turn onto the singletrack trail to your right. The trail is cut into the side of a steep hill, and in places is somewhat overgrown and eroded. It passes through chaparral, then descends into a narrow wooded ravine. The trail briefly follows a little crystal-clear creek that in spring cascades over some rocks. The trail then climbs out of the ravine and is mostly level the rest of the way to Cave Rocks Road.

Cave Rocks Road, Sunol Regional Wilderness

Cave Rocks Road

At Cave Rocks Road, one option is to turn right and take the Indian Joe Creek Trail. This trail descends through attractive oak woodland, eventually bottoming out in a pleasant glen where a little brook flows through grassy meadows. The trail crosses the brook several times; in the spring it may not be possible to do this hike without getting your feet wet. The only drawback to this option is that it’s kind of short (5.6 miles).

For a longer, 10-mile hike, skip the Indian Joe Creek Trail and instead turn left onto Cave Rocks Road. For the most part the extra mileage on this longer loop isn’t as scenic, but it results in a more satisfying all-day hike without adding a lot of extra climbing.

The dirt road climbs to Cerro Este Road, the high point of the hike. There are some nice views of the Calaveras Reservoir and the surrounding hills from this area. Turn right onto Cerro Este Road and descend steeply through open grasslands, then turn left onto the McCorkle Trail.

This trail isn’t especially scenic at first; the grasslands here seem kind of dry and dusty. But the scenery improves as the trail crosses over a little brook cascading down a jumble of rocks and then descends an oak-dotted hillside. Turn right onto Backpack Road, which is even more scenic.

At the end of Backpack Road, turn right onto Camp Ohlone Road. This dusty gravel road is the least enjoyable trail in the park, but it’s also one of the most heavily used, not only by hikers but also by equestrians and vehicles going to and from Camp Ohlone. It is, at least, fairly easy to hike.

Little Yosemite area, Sunol Regional Wilderness

Little Yosemite

Little Yosemite is a short stretch, maybe a few hundred yards, where Alameda Creek flows through a narrow, boulder-lined gorge created by a steep butte. There are some small waterfalls and pools among the boulders. This is the park’s most popular attraction, and the two shortest routes to get here, Camp Ohlone Road and the Canyon View Trail, are the park’s most popular trails, with 3 or 4 groups per minute on a really busy weekend.

Turn right onto Cerro Este Road and, after a short climb, turn left onto the Canyon View Trail, which climbs an escarpment above Little Yosemite. After crossing the McCorkle Trail, the Canyon View Trail descends steeply along a wooded ridgetop. There’s a nice finish to the hike as the trail passes through pleasant streamside forest.

Canyon View Trail, Sunol Regional Wilderness

Canyon View Trail

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