Mary Bowerman Trail, Mount Diablo State Park,
California State Parks,
Contra Costa County
In brief:
0.7 mile loop hike around the summit of Mount Diablo, with excellent views the entire way.

Distance, category, and difficulty:
This 0.7 mile loop hike is very easy. The entire trail is almost completely level, with just minor elevation changes.

Mostly exposed, with some pockets of shade.

Trail traffic

Trail surfaces
Dirt trail and one paved segment.

Hiking time
1/2 hour.

Too hot in summer. Best in late winter and early spring.

Getting there:
From Interstate 680 in Contra Costa County, exit Diablo Road (exit 39). Follow the green parks signs: drive east on Diablo Road (turn right at the junction with El Cerro), then turn left at the (stop sign) junction with Blackhawk onto South Gate Road. Drive carefully uphill on this narrow road (watch out for bicyclists) about 7 miles to a stop sign, then turn right onto Summit Road. Continue to the summit, about 4 more miles. Just before the road splits into two one-way segments, park in a small dirt area on the right (or park in the large lot back downhill a few yards).

Get driving or public transit directions from Transit and Trails:

GPS Coordinates* for Trailhead:
Latitude 3752'50.72"N
(* based on Google Earth data, shown as degrees, minutes, seconds)

Gas, food, and lodging:
Gas, stores, and restaurants back near I-680 in Danville. The park has group campgrounds and individual campsites. Visit MDIA's website for more info.

Trailhead details:
A few designated handicapped parking spots across from the start of the trail, and the first 0.18 mile of the trail is suitable for wheelchairs. Lots more parking just downhill in a big paved lot. $10 entrance fee. Restrooms, pay phone, and maps a little further uphill at the Summit Visitor Center (a brochure is usually available at the start of the trail). Gas, restaurants, and stores in the town of Danville, near the 680 exit on Diablo Road. There is no direct public transportation to the park. Note: carsick alert! If you or anyone in your vehicle is prone to carsickness, drive very slowly (no more than 20 mph) on the park roads. As there is no optional route to the top, slow smooth cornering may help avoid carsickness.

No bikes or dogs. Horses are technically permitted, but you will probably not encounter any on this trail. The park is open from 8 a.m. to 45 minutes before sunset.

The Official Story:
CSP's Mount Diablo page
Mount Diablo Ranger Station 925-837-6129

Map/book choices:
This hike is described and mapped in 60 Hikes within 60 Miles: San Francisco, by Jane Huber (yup, that's me, the creator of this website). Order this book from
• Download the park map pdf from CSP's website.
Mount Diablo (& Surrounding Parks) map, published by Mount Diablo Interpretive Association, is invaluable (order at
Mount Diablo Interpretive Association offers many featured hikes and events that explore Mount Diablo. You can also order maps and books through them.
Save Mount Diablo is a good source of current events on the mountain, including the progress of preservation campaigns.
• David Weintraub's East Bay Trails features descriptions of several Diablo hikes, with accompanying maps (order this book from

Mary Bowerman Interpretive Trail in a nutshell -- a printable, text-only guide to the featured hike.

View 43 photos from this hike.

Go to Bay Area Hiker Home page

If you've never been to Mount Diablo, the summit is a great place to start. TrailheadAt the Summit Museum and Store, you can view some educational exhibits, pick up maps, free brochures with suggested hikes, and the pamphlet that accompanies the Mary Bowerman Interpretive Trail. Then head downhill about 500 feet from the summit parking lot to the Mary Bowerman Interpretive Trail (renamed in 2009 from Fire Interpretive Trail). The 0.7 mile path (the first portion of which is paved and wheelchair-accessible) is a self-guided tour that informs visitors about geology and plants, all the while offering basically the same astounding views as the summit, without the crowds. After completing the short loop, if you're inspired and immediately ready for more hiking, you can head out from the summit trailhead to North Peak, a close to 5 mile out-and-back trek, or head back downhill in your car to one of the other trailheads off Summit Road and explore some different perspectives of the mountain. View to North Peak from Fire Intrepretive Trail
     Summer is my least favorite time of year to visit Diablo. July is not the time to hike the 9 mile loop from Mitchell Canyon to the summit and then back down again (never again). Too hot and dry! Diablo's famously expansive views are diminished during smoggy summer days, while clear winter days afford the best vistas, as well as comfortable hiking. Spring and autumn possess their own charms, most notably wildflowers in spring (but also muddy trails), and deciduous foliage (primarily maples, black oaks, and poison oak), fewer visitors, and frolicking tarantulas looking for love in autumn.
      For the featured hike, start at the Mary Bowerman Interpretive Trailhead: if you've driven to the the summit, get back in your car and drive back downhill to where the two one way sections of the road rejoin. There are a few spaces on the left side, and if those are full, keep going a little further to the huge flat parking lot on the left. Walk back across the street from the small parking area, and look for the signed start of the trail. Canyon live and interior live oaks canopy the flat paved path. Post two serves to identify poison oak, but if you're visiting in autumn and winter, all you'll see is a dead-looking bunch of branches.Viewpoint on Fire Interpretive Trail  Beware, though, for this leafless foliage still exudes itchy oils. Mary Bowerman Interpretive Trail steps out into rocky chaparral. With the help of the interpretive pamphlet, you can learn about the rocks of the mountain: greenstone, greywacke, and chert. A long look downhill to the left reveals a quarry where diabase is mined. Along the sides of the trail look for creambush, clematis, California bay, and some gray pine. A wooden platform with benches makes a fine rest stop,where you can check the keys to distant and nearby land features. On a hazy day, it's hard to believe that clear weather permits occasional glimpses of Mount St. Helena (66 miles away), Snow Mountain (112 miles), Lassen Peak (181 miles), and even the Sierra Nevada. View uphill to the summit Unless the weather is completely uncooperative, you should be able to identify Mitchell Canyon and Suisun Bay. Just past the end of the wooden platform, at 0.19 mile, the paved part of Mary Bowerman Interpretive Trail ends (wheelchair users and folks with strollers, this is your turnaround point).
      While enjoying the unobstructed view of North Peak, keep an eye open for soaring hawks. Mary Bowerman Interpretive Trail enters a dry area dominated by chaparral plants. The rocky, level, and narrow trail is lined with cercocarpus, buckbrush, pine, creambush, bay, and shrub-like interior and canyon live oaks. As the trail sweeps through a bare stretch, the red-tinged monolith known as Devil's Pulpit looms ahead.Mary Bowerman Interpretive Trail curves to the right, at 0.38 mile, revealing a nice view uphill to the summit. View downhill to the south Grassland dominates the landscape, and you may see at least one or two wildflowers just about any time of the year, sprinkled throughout the grass. Native juniper shrubs hunker close to the ground here and there. The views of the southern section of the park are stunning. Chamise and yerba santa thrive on the rocky slopes and near the end of the trail oaks, and poison oak crowd the path. A blue elderberry tree stands guard as the trail empties out into the small parking area. If you are visiting in late summer or autumn and haven't been lucky enough to encounter a tarantula on the trails, keep a lookout on the drive back downhill. They sometimes can be spotted crossing Summit Road (here's a photo).

Total distance: 0.67 mile
Last hiked : Saturday, September 16, 2012