Palos Colorados Trail Reroute

Like most trails in the region, the Palos Colorados Trail in Joaquin Miller Park took a beating last winter. The above-average precipitation was much needed, but water is a trail’s most destructive force. The heavy rains caused many trees to fall, and landslides took out whole sections of trail. To respond, Oakland Trails volunteers cleared several fallen trees, shored up four slides, and moved the creek crossing upstream to help ensure hiker safety. We saved this biggest project for last.

As you can see in the picture above, the trail below the bay tree was failing. With a steep drop off below, this very narrow section of trail was sliding into the creek and had become unsafe.

To begin planning the repair, I met on site in August with Oakland Public Works staff, including a maintenance supervisor and arborist, and trails expert Dee Rosario. Together, we assessed the failing trail and devised an appropriate plan to fix the problem. With confirmation that the large bay tree was healthy and could not be removed, we agreed the trail would have to be moved to above the tree. This would require about 80 feet of new trail. To accommodate the reroute, a crib wall would have to be built below the tree, and a full bench would need to be cut into the hillside above the tree.

To prepare for this project, I escorted Public Works staff to the site – about 1/2 mile up the narrow trail – so they could help us by clearing out thorny blackberries and poison oak with power tools (the ferns in the picture were spared and transplanted nearby). Next, over several volunteer work sessions, we would begin working on the crib wall.

Back in March, several eucalyptus trees fell across the bottom of Cinderella Trail. Because eucalyptus is naturally rot-resistant, we stashed the cleared tree trunks alongside Sunset Trail for any future needs. It was from here that we’d gather free material to build our crib wall.

Green eucalyptus is dense and heavy. We cut the logs to lengths we could handle, then carried them one by one almost 3/4 mile to the work site.

We also had to hand carry the necessary tools and other materials to the site, including digging tools, 5/8″ rebar, and sledgehammers.

Work on the crib wall began. The cross pieces in the first layer were secured nearly two feet into the hillside for stability.

The crib wall was constructed with 3 foot pieces of 5/8″ rebar.

Over ten work sessions with crews of 2–4 volunteers, we continued to supply the work site with materials so we could finish layering the crib wall. With the crib wall almost complete, it was time to cut out the trail above the tree so we could close the old trail and open the reroute.

On a Sunday in late September, we enjoyed the help of the Friends of Sausal Creek trail crew. By the end of their work session, the new trail had been formed. Over the next few days, Oakland Trails volunteers would come back to put in the finishing touches. We added some timber supports to the uphill side of the trail, and installed a few steps.

With our work almost finished, we reached out to Public Works staff for an inspection. It passed with flying colors! This trail should be safe and accessible for another 20 years.

We’d like to Oakland Public Works, Friends of Sausal Creek, Friends of Joaquin Miller Park, Rob Werner & Siew Chan Werner, and Ashby Lumber for their partnership on this project. Also thanks to Park Patrol volunteers Gary, Evan, Chris, Paul, Nelson, John, and Luke for your many hours of hard work!

Total volunteer work days: 16
Total volunteer hours: 150