If you've never been to Mount Diablo,  the summit, and nearby Mary Bowerman Interpretive Trail are great places to start. At 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.
     Summer is my least favorite time of year to visit Diablo. Take it from me, July is not the time to hike the 9 mile loop from Mitchell Canyon to the summit and then back down 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. 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. 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. Although the pamphlet urges you to look for signs of the 1977 fire, it takes an experienced eye to discern any change in the vegetation. 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. 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

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