Mt Diablo State Park and Walnut Creek Open Space are accessible through Diablo Foothills, an imposing entrance to the stunning parklands of Mt Diablo State Park and Walnut Creek Open Space. 


The 1,060 acres of the Foothills are prized for their striking geologic formations, expansive views of the San Francisco Bay Area, and the rural quality of the surrounding rolling grasslands. Diablo Foothills Park has Castle Rock Recreation Area.


Diablo Foothills' 1,060 acres contain fascinating geologic features, colorful wildflowers in season, and a range of bird and animal life, in addition to panoramic views of the mountain and its surroundings.


The vegetation in the valley ranges from riparian and oak forests in the hills to grassland and oak savannah in the valley. 


Pine Creek runs through Pine Canyon and is part of the Walnut Creek watershed, which drains 150 square miles of central Contra Costa County to the San Francisco Bay.


Mule deer, bobcats, coyotes, gray fox, long-tailed weasels, raccoons, gophers, rodents, and ground squirrels are among the species that thrive in a variety of habitats. 


Red-winged blackbirds, northern mockingbirds, scrub jays, California quail, and brown towhees are among the birds that use the park for breeding and foraging. 

Garter and gopher snakes, western fence lizards, southern alligator lizards, tree frogs, and California salamanders all live in rock outcrops. Green sunfish, mosquitofish, and largemouth bass thrive in Pine Creek's permanent bodies of water.


Horseback riding, camping, bicycling, and nature research are all common activities in the Diablo Foothills. The park does not have any developed infrastructure.


Planning to hike the trails? 

This hiking begins in a shady wooded gorge, then opens into sweeping open grasslands before climbing to the top of a blue oak-strewn knoll. The gradual transition between various conditions allows for a fantastic hike with plenty of variety.

Surprisingly for a small park on the outskirts of town, the road is remarkably undeveloped, with just a few signs of growth at the beginning and end. However, there are some stables right at the trailhead, and the trails are littered with horse manure.


  • Start at either the small parking lot at the end of the fun rural Castle Rock Road or the big gravel parking lot a few hundred yards up the road; the hike is the same length.

  • Enter the Castle Rock Regional Recreation Area via the paved route. This small established park in Pine Canyon has some beautiful wooded picnic areas, but the main draw is a swimming pool shaded by some massive oak trees.

  • Continue on the well-traveled canyon-bottom route. Above you can see the Castle Rock rock formations, which are very beautiful. Before disappearing under the shady tree canopy, the trail runs across a few short sunny meadows.

  • A small picnic area in a blue oak grove at a big spot in the canyon is located at the junction with the Little Yosemite Trail. The majority of people proceed along Stage Road, but it reaches Mount Diablo State Park shortly after the picnic area and becomes less scenic. Instead, take the Little Yosemite Trail to the right.

  • The singletrack trail climbs past a small seasonal waterfall and past a rock formation. It climbs through a wooded side canyon that opens up steadily, then emerges into bright, sunny grasslands, a stark contrast to the canyon's deep shade.

  • Turn onto the Briones to Mount Diablo Regional Trail, which rises and falls as it winds through the oddly bumpy terrain, providing lovely views of the scenic blue oak-strewn hills below and Mount Diablo above. 

  • The trail passes China Wall, an unusual rock formation composed of two lines of standing rocks, before settling into a steep, slow decline after a final slope.

  • The Fairy Lantern Trail will take you down into an oak-forested canyon. If you've had your fill of hiking, you can follow the Fairy Lantern Trail all the way to Stage Road. 

  • Turning onto the Shell Ridge Loop Trail, on the other hand, is a far more scenic and interesting alternative.

  • The Shell Ridge loop takes you up one of the area's steep, oak-capped knolls. Given how steep it is, it is remarkably popular; after the Stage Road Trail, it is possibly the park's second most-used trail.

  • The Shell Hill Loop ascends a ridge across an expansive blue oak grove with a grassy lawn behind it. The gradient is gentle until you're nearly at the brink, where you'll face a sharp ascent to the mountain, followed by a steep descent. 

  • An unofficial trail skips both the ascent and the descent, as well as some of the beautiful hilltop scenery, including views of Pine Canyon to the south and Walnut Creek to the north.

This amazing park is just one of the many must-see parks you don’t want to miss in Walnut Creek, California:

  • Heather Farm Park

  • Civic Park

  • Arbolado Park

  • Acalanes Ridge

  • Walden Park

  • Howe Homestead Park

  • Heather Farm Dog Park

  • Sugarloaf Open Space 


All of these wonderful parks are located just a short distance from our location at 1261 Locust Street in Walnut Creek!