In 2014 we celebrated the 40th anniversary of the founding of the Mount Diablo Interpretive Association. One of the first major projects undertaken by the infant association was a survey of the park’s trails network. Small groups of dedicated hiker-environmentalists spread out over the far reaches of the park as it was in the mid-’70s, assessing the existing trails and recommending new trails. One recommendation was construction of what is now known as the Mary Bowerman Trail. The summit of the main peak was a primary destination of the visiting public, but no trails were there for visitors to experience close contact with the mountain’s exceptional natural environment.

The first step was to lay out a possible route. Surveys of the topography revealed that a logical circuit of the summit region could be visualized with no anticipated damage to plant life and geological formations. The circuit was to be fairly level, along a contour line, with an overall distance of about a mile. Full of enthusiasm, our little band of interpreters marked the route with wooden stakes with red ribbons. We came back a few days later to find almost all of the stakes gone! So back we went and repeated our layout. A couple of days later, the same thing! And then it dawned on us. This was not the work of vandals, it was the work of animals (raccoons? skunks?) resenting this intrusion into their homeland. This was one of many delays; some, as expected, came as a result of environmental reviews by the Department of Parks and Recreation in Sacramento. Finally, with preliminary approval, Park Ranger Dick VanEtta single-handedly constructed a primitive path along the proposed circuit, in just a few days.

But all in vain. For it was August of 1977, and soon after VanEtta’s efforts, lightning struck on Twin Peaks, and the resulting fire roared upward toward the summit. The summit buildings were saved, but the fire destroyed the plants on the north-facing slopes below, as well as vestiges of the new trail. The Bay Area was stunned by the damage to the park, and money poured in to help regeneration, along with suggestions which simply proved that many kind-hearted people did not understand that post-fire regeneration was best left to nature. Proposals such as aerial scattering of grass seeds, planting of redwood groves, even introducing palm trees were mercifully rejected.

But the money was put to good use. The decision was made to build the trail as originally envisioned, through the burnt area, and to dedicate the trail to fire interpretation. After almost five years of planning, a spectacular trail, The Fire Interpretive Trail, was completed in 1982 by a wonderful group of young people from the California Conservation Corps, under the direction of Carlos Espinoza, a dynamo in a wheelchair. A grand trail dedication was held at the trailhead, with lots of visiting celebrities, fluttering flags, and politicians. William Penn Mott Jr., then superintendent of California State Parks, spoke, as did Senator John Nejedly and Mary Leo Bowerman, celebrated botanizer of Mount Diablo. Dr. Bowerman was a founding member of MDIA and co-founder of Save Mount Diablo, our sister organization. Dr. Bowerman passed away in 2005 at the age of 97; The Fire Interpretive Trail was renamed in her honor. Following extensive incineration during the recent Morgan Fire, the trail continues to serve as a fire interpretive trail, to allow the public to monitor post-fire recovery of the plant communities over the coming years.

Ironically, Dr. Bowerman did not originally favor a trail through the area. She was afraid, with some justification, that the construction effort and large visitor volume would impact the fragile plant life. Fortunately, rare and sensitive plants such as Bitterroot (Lewisia Redidiva) have fared well. The trail has been developed as a nature trail, and numbered posts refer to some highlights listed in a brochure available in a box at the trailhead.

The 0.7-mile loop is no great challenge to the dedicated hiker, but with the help of the trail brochure, it offers an unusual range of discoveries. There is actually much more to see than the described features at the numbered posts, and close observation rewards you with some surprises. For instance, upon reaching the wooden platform called “The Bridge”, you might notice in the lower right corner a textbook example of a geological nonconformity. This is a phenomenon of two different rock types (in this case, shale and greenstone) being joined together along a seam. This kind of sudden change implies that the two rock types, formed separately perhaps millions of years apart, were squeezed and rubbed together by displacement forces, such as the upward thrust of the mountain’s piercement structure. On the trail’s southern rocky section, look for evidence of “slickensides”, highly polished surfaces formed by friction between rock masses moving relative to one another. During the spring months, be on the lookout for some unusual wildflowers. Just beyond The Bridge, at the point where the trail turns sharply toward the east, you pass a cherty scree slope on your right. Close inspection of the loose rocks will reveal the presence of small plants struggling to come to the surface, in the shape of small green spiders about the size of a tarantula. These are examples of Bitterroot, and if you are lucky, you will be there to welcome the spectacular white blooms. Other flowers worthy of attention: Brewer’s Rock Cress, seemingly growing out of the rock, in greenstone crevices in the cliff behind The Bridge. Astounding fields of pink Claytonia smothering an expanse of broken chert just before you reach the short side trail to Devil’s Pulpit. The side trail is often graced in June with Mariposa Lilies, and miniature Penstemon fight to survive at the base of the Devil’s Pulpit monolith, a favorite climbing rock.

Ah, there are so many wonderful things to see on this trail, which, along with MDIA, has now been with us some forty years. After parking your car at the lower summit parking lot, walk up a few steps to the trailhead, at the bottom of the steep one-way road leading to the summit. A clockwise circuit is recommended; you will finish your hike just across the road from the trailhead. Enjoy and celebrate! Mary Bowerman Interpretive Trail Guide

Check out more Spring Wildflower Hikes:

Globe Lily Trail

Springtime in North Peak

Black Point Trail