TRAIL 25 East Bay

Pleasanton Ridge Regional Park

TRAIL USE

Hike, Run, Bike, Dogs Allowed

LENGTH

12.3 miles, 6–8 hours

VERTICAL FEET

±3000'

DIFFICULTY

– 1 2 3 4 5 +

TRAIL TYPE

Loop

SURFACE TYPE

Dirt

FEATURES

Stream
Canyon
Summit
Wildflowers
Birds
Great Views
Photo Opportunity
Secluded

FACILITIES

Restrooms
Picnic Tables
Water

The hike along Pleasanton Ridge, although one of the longest and most challenging in this guide, is also one of the most rewarding (several shorter options are also enjoyable). Outstanding views extend from Pleasanton, San Ramon, and Mt. Diablo to Sunol Valley, the Sunol/Ohlone Wilderness, and Mission Peak. Bird and plant life flourish in this relatively undeveloped park. The varied terrain includes dense woodland, open grassland, and even a restored olive orchard.

Best Time

Fall through spring, but trails may be muddy in wet weather.

Finding the Trail

From Interstate 680 in Pleasanton, take the Sunol Blvd./Castlewood Dr. exit and go southwest on Castlewood Dr., staying straight where Pleasanton–Sunol Rd. bends left. After 0.3 mile, you reach Foothill Rd.; turn left and go south 1.6 miles on Foothill Rd. to the Oak Tree Staging Area, right. The trailhead is on the west side of the first parking area.

Trail Description

From the parking area, follow a dirt road west through a cattle gate, then bear left at a junction1 and begin climbing moderately on the Oak Tree Trail, also a dirt road. Continue past the hiking-only Woodland Trail, left.

The route ascends on a winding, open course through open grassland dotted with valley oaks. Midway through a broad 180-degree bend, you pass a junction with the Sycamore Grove Trail, right. As the road climbs south, an unsigned single track parallels it below and left.

The view south from Pleasanton Ridge includes Mission and Monument Peaks (right).

At about 1.3 miles, you emerge from a wooded area and reach a five-way junction near a barbed-wire fence.2 Here, the Woodland Trail joins on the left, and an unnamed dirt road follows the fence left and right. Your route, the Oak Tree Trail, turns right and goes through an opening in the fence. About 30 feet beyond the fence is a junction. Here you leave the Oak Tree Trail, which goes left, and join the Ridgeline Trail by angling right.

The Ridgeline Trail makes a 180-degree bend to gain the ridgetop. Soon you pass a connector to the Olive Grove Trail, which branches left. Follow the Ridgeline Trail by bearing right, heading generally northwest, and climbing moderately past the first of two stately olive groves. The groves here were planted between about 1890 and the 1920s, but there is no record of who planted them. Just beyond the grove are a drinking faucet, a watering trough for animals, and another fork, where you continue straight. Rising steeply over rocky ground, your route eventually levels and comes into the open.

Where there are oaks in the East Bay, you are likely to find acorn woodpeckers.

Pause often to enjoy the view, which extends from Mt. Diablo south to Mission and Monument peaks. San Antonio Reservoir, with the Sunol/Ohlone Wilderness behind it, is southeast; and forested Sunol Ridge, topped by a single communication tower, rises above Kilkare Canyon and Sinbad Creek to the west. Now you pass a junction3 with the Olive Grove Trail merging sharply from the left. Along the ridgetop, you climb over several high points, the first of which is just ahead. There is a picnic table atop one of these rounded summits. Soon you descend to a saddle and a fork. Your route bends right and climbs steeply to the summit of a grassy hill.

Continuing on the Ridgeline Trail, you climb steeply over several more hills. Finally, the route leaves the ridgetop, veering right and downhill through a cattle gate, then descends over steep and rocky ground. Traversing north through dense forest, you soon enter Pleasanton’s Augustin Bernal Park. Now out of dense forest, you drop to an oak-shaded saddle and a junction, left, with the Thermalito Trail, your eventual return route.4 A few steps left along the trail are drinking water and a trough for animals.

Great Views

Continue straight on the Ridgeline Trail, sauntering moderately uphill through an oak savanna. Soon, an equestrian-only trail crosses your route, and then the Valley View Trail merges from the right. Ahead about 0.3 mile is a gate marking the boundary between the city and regional parks. Just beyond the gate is a fork. Bear right and enjoy a mostly level stroll through a beautiful oak savanna. After about 0.4 mile, the left branch of the previous fork rejoins, and now the Ridgeline Trail begins to climb.

As the route breaks into the open, you pass a pond, left, and a junction with the Sinbad Creek Trail, also left, part of your return route.5 For now, continue straight, passing another small pond. At a junction near the park boundary, you go straight on the Bay Leaf Trail,6 then bend left and begin to descend. Soon the route turns sharply right and drops into a ravine on a moderate grade.

Now the route crosses two creeks that flow under the road through culverts. After an open section, you pass a junction right, with the single-track Sinbad Creek Trail.7 Your route follows the road, now also named the Sinbad Creek Trail, downhill. You soon reach Sinbad Creek at the bottom of Kilkare Canyon.8 Step across the creek on rocks and, at a T-junction with a dirt road, turn left. After a pleasant, 0.7-mile streamside stroll, you arrive at a T-junction in a clearing.9 Here you turn left, recross the creek, and begin climbing steeply out of the canyon on the Sinbad Creek Trail, a dirt road.

Stream

Cresting the ridge, you soon come to a T-junction with the Ridgeline Trail.10 Turn right on the Ridgeline Trail and retrace your route to the junction of the Ridgeline and Thermalito trails. When you reach that junction,11 turn right on the Thermalito Trail, a dirt road.

OPTIONS

Shorter Trips

For a different shorter loop, another good turnaround point is the Ridgeline/Sinbad Creek trail junction,5/10, which reduces your total trip distance to 9.3 miles. But first, continue right on an unsigned path to a rest bench overlooking the I-680 corridor and Pleasanton. Then return to the junction and start back on the Ridgeline Trail.

Another option is, when you’re in Augustin Bernal Park, to turn left on the Thermalito Trail 4 and follow the route description from11. This route reduces your trip distance to about 7 miles.

Now the route roller coasters over rocky ground, passing a picturesque pond, to a T-junction, where you stay right on the Thermalito Trail. Out in the open now, the road descends past a stock pond to a small ravine, which may hold water during wet weather. Crossing to the other side of the ravine, the route climbs slightly, bringing you to another pond, right, and a junction.12 Leaving the Thermalito Trail as it turns right, you continue straight on a connector to the Olive Grove Trail. Walking east about 100 yards, you get on the Olive Grove Trail by going straight. At the next junction, where the Olive Grove Trail swings right, go straight on a connector to the Ridgeline Trail.13 At the junction with the Ridgeline Trail,14 bear right and retrace your route to the parking area.15

MILESTONES

Trail 25

1 0.0 Take dirt road west to junction and start up the Oak Tree Trail

2 1.3 Right at five-way junction to stay on Oak Tree Trail, then right on Ridgeline Trail

3 1.9 Olive Grove Trail merges from left

4 3.4 Thermalito Trail on left; go straight to stay on Ridgeline Trail

5 4.5 Sinbad Creek Trail on left; go straight

6 4.9 Straight on Bay Leaf Trail

7 5.7 Straight on Sinbad Creek Trail (dirt road)

8 5.8 Cross Sinbad Creek, then left at T-junction to stay on Sinbad Creek Trail

9 6.5 Left at T-junction, cross creek to stay on Sinbad Creek Trail

10 7.4 Right at T-junction with Ridgeline Trail

11 8.5 Right on Thermalito Trail

12 10.5 Straight on connector to Olive Grove Trail; straight on Olive Grove Trail

13 10.7 Straight on connector to Ridgeline Trail

14 10.8 Right on Ridgeline Trail, then follow Oak Tree Trail

15 12.3 Back at parking area