Mitchell Canyon was preserved in 1974 through the work of Save Mount Diablo. North of Clayton and on the mountain's north face, it puts on one of the best spring wildflower displays in the Bay Area. This beautiful canyon is heavily wooded with alders, willows, and oaks. Huge grapevines hang from the many trees. The creek, sparkling and rushing as it descends, sometimes exposed, at other times protected by thickets of blackberry and poison oak, is the canyon's real gem.

Mostly undeveloped, Mitchell Creek joins Mt. Diablo Creek soon after leaving the State Park. The upper watershed is secure within the Park while much of the lower drainage, which stretches all the way to Suisun Bay, is isolated within the Concord Naval Weapons Station. Short developed sections in Clayton and Concord, which include flood control drop structures and barriers, have isolated the creek from the Bay.

And therein lies the story. When trout migrate to saltwater they become steelhead, and they sometimes mix with populations from neighboring streams as they return to spawn. Rainbow trout aren't unusual, but native rainbow trout are almost extinct. Most trout populations have been cross-bred with genetically compromised hatchery raised fish and resemble a native trout about as much as a house cat does a bobcat. Only two or three genetically pure rainbow trout populations are thought to survive. All are in the, East Bay, with an identified population found in Mitchell Creek in 1985.

Unfortunately, past uses have severely damaged some areas of Mitchell Canyon and the trout may have vanished. The damage began during the mid 1800s when mining fever was rampant in California. Mt. Diablo was heavily prospected and many mines were dug, sending sediments into stream canyons including Mitchell. In addition, grazing has heavily impacted the steep canyon and its fragile riparian (streamside) habitat.

During the 1977 Mt. Diablo fire, which burned from Clayton to BIackhawk, firebreaks were bulldozed throughout the canyon. Those bulldozed areas and the canyon floor's fire road erode into the creek during winter rains. Mitchell Creek is spring fed with isolated pools remaining throughout the summer. However, broken dams and old structures restrict fish migration between pools. In addition, several long droughts during the last twenty years may have been the proverbial j’straw that broke the camel’s back’, possibly eliminating the beautiful fish.

The last recorded collection of trout from Mitchell Creek was in 1985, when the Department of Parks and Recreation found 13 fish in a survey sample, suggesting an estimated total population of 190 fish. Unofficial observers have seen fish as recently as several years ago, but surveys performed in 1997 found none. However, the surveyors could not get to the shady sections of the creek protected by dense thickets of blackberry and poison oak, meaning that there is still the chance that trout remain. Should they be gone, they can be reintroduced from the two remaining native populations (in the Oakland hills), if the creek habitat is first improved and restored.

The State’s update of the Mt. Diablo State Park General Plan recommended a trout recovery plan. More importantly for the creek, it mandated the removal of cattle from much of the park, a task completed in 1994. Cattle grazing issues aside, the immediate result of their removal was increasing health for the vegetation and the creek in Mitchell Canyon. Unfortunately State park budget cuts over the past decade have left the park under funded and short-handed, and a trout recovery plan was not implemented.

Enter Clayton resident and Save Mount Diablo volunteer John Roskelley, who has fish on the brain and who has played in the creek since he was a kid. Hohn had seen trout in the creek two years earlier, bbut the decreasing numbers had him worried. He approached Save Mount Diablo and State Park superintendent Larry Ferri with the idea of using volunteers to restore Mitchell Creek, and both enthusiastically agreed.

It was decided early that the emphasis would be placed on restoring the habitat for the sake of the over all canyon’s health, not just the trout Riparian areas, like those along Mitchell Creek, are some of the most valuable habitat for wildlife, providing important migration routes, nesting sites, food, shelter, and water. The goal of The Mitchell Canyon Creek Restoration Project is to restore damaged areas within the canyon to a healthier state, and to reduce corrent disturbances as much as possible.

Objectives include, 1) determining whether the fish are still there, 2) conducting historical research to insure that the population is in fact native, 3) assessing the creek’s flows and temperatures to insure that fish can survive seasonal fluctuations should reintroduction be proposed, and 4) preparing an overall Restoration Plan.

The project will span at least three years, with much of the work being done by volunteers. Tasks will include creek monitoring, removal of non-native plants and reintroduction of native plants, installation of horse watering troughs, and removal of sediments, old culverts and other structures blocking upstream migration.

Gathering baseline data about the hydrology of the creek and its value as habitat is an important step in the restoration. Water monitoring stations have been set up at one location downstream where flow is seasonal, and one location where flow is year round. Temperature and flow volume and velocity measurements are taken twice a week, to monitor changes in the creek resulting from restoration efforts.

Creekside vegetation is as important to a creek as the water that flows through it. Alders, willows and sycamores provide habitat for birds and other wildlife. Roots hold the soil in place, stabilizing creek banks and limiting erosion, grapevines and shrubs along the creek provide hiding places and house the insects that are food for birds and fish.

Some stretches of Mitchell Creek were so overgrazed that there is very little streamside vegetation and trees. Restoring vegetation along bare creek banks (native oak trees, alders, buckeyes, wild rose, mugwort, and snowberry) will shade the water, lowering its temperature, thereby benefiting the trout and other aquatic species.

There are a number of non-native plants that are very invasive and beginning to take over parts of the creek. Among the non-native plants are periwinkle, poison hemlock, bull thistle, and Himalayan blackberry. A large part of the Mitchell Creek restoration will be to remove these non-native plants, while propagating and replacing them with native stock.

Some work has begun. A propagation area is being built near the canyon's mouth and plant propagation will begin soon. The first volunteer workday was in November, when fifty two enthusiastic people showed up, despite the threat of rain, to rip out the periwinkle that was taking over the creek banks. About one fifth of all the periwinkle was pulled out that day; upcoming workdays will focus on the remaining patches.

So are there trout in Mitchell Creek? We're not sure, but if you join our volunteers and do a little work to benefit our mountain, you may be among the first to know. If you'd like to get involved, call the Save Mount Diablo office at 947-3535 and leave your name, phone number and address.