The Fifield-Cahill Ridge Trail shows you hidden sides of the Crystal Springs Reservoir on docent-led hikes (and best of all — it’s expanding!)

The Fifield-Cahill Ridge Trail, located entirely on property owned by the San Francisco Public Utilities Commission, offers stunning views of nearby reservoirs used to provide drinking water to Peninsula residents. (Courtesy SFPUC/Robin Scheswohl)

Hidden off a dirt road in the Skylawn Memorial Cemetery in the hills between San Mateo and Half Moon Bay is a pristine trail that runs 10 miles through the Peninsula’s most protected open space.

You can’t go there alone — you’ve got to sign up to go with a trained docent — and you need a reservation. But the views from Fifield-Cahill Ridge Trail are worth the hassle.

The trail runs for 10 miles, starting at the Skyline Quarry off of State Route 92, between Half Moon Bay and San Mateo, and ending at the Portola Gate at Sweeney Ridge, an open space preserve between Pacifica and San Bruno. The forested ridge the trail runs along is owned by the San Francisco Public Utilities Commission (SFPUC). The area is part of a 23,000-acre property the utility owns and manages as part of the watershed it controls.

All of the protections that surround the trail are there for good reason: It’s near four Peninsula watershed reservoirs that provide the drinking water for San Francisco and other communities, and there are a number of protected species found there, such as the California red-legged frog, San Francisco garter snake, Bay checkerspot butterfly, steelhead and the marbled murrelet. According to Tim Ramirez, land and resources management manager at the SFPUC, around 2002, the trail was opened up to the public using the docent-led approach. Docents are trained volunteers, and through their efforts, the trail can be accessed three days a week for up to three trips per day, on Wednesdays, Saturdays and Sundays.

The Fifield-Cahill Ridge Trail requires a reservation and a docent guide to access. (Courtesy SFPUC/Robin Scheswohl)

The Fifield-Cahill Ridge Trail

On a recent Saturday morning, I joined a guided hike to explore a segment of the trail, meeting my trail docent, Peninsula ultrarunner Suki Martin, on the highway pullout near the entrance of the Skylawn Memorial Cemetery. From my car, I followed Martin through the winding roads of the cemetery to a roughly paved road, then a dirt road through a gate with a modestly sized parking area.

With the rest of our hiking group, three men from the East Bay who were experienced hikers and in training for a summer backpacking trip, we set off down the trail, a well-maintained dirt fire road.

Another group on bikes, led by a cyclist docent, quickly passed us.

The hike developed into a roughly seven-mile out-and-back journey, with views of the Crystal Springs Reservoir on one side and the Pilarcitos Reservoir on the other, plus tidy pit toilets every couple of miles. Though the forecast called for rain, likely deterring a larger group from joining our trip, we only caught some light mist at the tail end of the hike.

The plant life along the way was lush and verdant, and it was exciting to get a pedestrian perspective on the green hills I find so soothing when driving along Highway 280. I left the trail after several hours, happy to have explored a new trail and seen the Peninsula from a new perspective, eager to share the experience with others. I had no idea about the plans, decades in the works, to expand the trail and make it more accessible set to move forward in the coming weeks.

The Fifield-Cahill Ridge Trail will be expanded with a half-mile loop to make it more accessible to all visitors. (Courtesy SFPUC/Robin Scheswohl)

New trails to come

Those expansion plans were about 20 years in the making, and passed a key milestone on May 11, when the San Francisco Public Utilities Commission voted unanimously to approve plans to build a new trail on its Peninsula property, the Southern Skyline Ridge Trail.

The trail will stretch six miles along Skyline Boulevard, from the south side of State Route 92 to the Phleger Estate Property, just across Skyline Boulevard to the Purisima Creek Redwoods Open Space Preserve. And, rather than limit access to guided expeditions as on the Fifield-Cahill Ridge Trail, this trail will be accessible simply by securing a permit in advance.

The commission also approved a new half-mile loop trail connected to the Fifield-Cahill Ridge Trail to make the trail more accessible for everyone, particularly field trip visitors.

As the owner of the Peninsula Watershed property, the SFPUC’s first priority is to protect the water supply, not to provide recreation services, although expanding access is a goal for the agency, Ramirez explained.

“We’re a water agency, not a public park entity,” he said. “We thought this was an area we could make a little more accessible.”

(Image via Yelp)

The vision for the Southern Skyline Boulevard Trail has been around at least since 2001, since a management plan for the property was approved that features the trail, said project manager Mary Tienken to SFPUC commissioners in a hearing over the project’s approval.

As approved, the new trail will run along Skyline Boulevard, also known as State Route 35, and will include a new 20-car parking lot and two new restrooms.

To access this new trail, visitors must get a permit from the SFPUC. To receive a permit, applicants will be asked to complete some form of an educational program to learn about the watershed’s purpose and function, the sensitive resources that surround it, and the visitor rules and restrictions. Permits are expected to be accessible through the SFPUC website or by contacting a community liaison for the SFPUC if the applicant doesn’t have internet access.

The project, expected to cost $21.8 million, has received a $1 million grant from the Metropolitan Transportation Commission in federal funds, according to SFPUC documents.

Key behind the effort to expand public access to the area is the Bay Area Ridge Trail Council, Ramirez said.

“The ridge trail extension is one of our largest projects and will open a stunning six new miles of trails to the public to enjoy, getting us close to our 550 continuous trail vision,” said Liz Westbrook, trail director at the Bay Area Ridge Trail Council.

“There is no question that there is need for broader public (trail) access on the Peninsula and we are so pleased that the new ridge trail extension will be available to the public via permit system,” she told the SFPUC commissioners before they approved the plan.

This map shows the planned updates to the trails on SFPUC property through the Peninsula. Indicated in pink is the new Southern Skyline Ridge Trail route, while the green line shows the new Universal Access Loop Trail along the Fifield-Cahill Ridge Trail. Courtesy San Francisco Public Utilities Commission.

The next step for the project is to put the project out to bid, find a contractor, and begin work on building the trail as soon as 2022. It’s expected to take about a year and a half to complete after construction starts, Tienken said.

However, the project comes with some other next steps that have yet to be fully worked through.

One challenge with the project — and one that the environmental study found would leave a “significant and unavoidable” impact — is on the dangerous conditions that will emerge from pedestrians on the trails having to navigate the busy vehicle intersection at State Routes 92 and 35, according to the project’s environmental report, which was approved by the San Francisco Planning Commission April 29.

To reduce that impact, the SFPUC plans to work with Caltrans to design, fund and build one of two possible options: a grade-separated bridge for pedestrians, cyclists and equestrians over State Route 92 at the east leg of the intersection with State Route 35, or a roundabout to direct vehicles through the State Route 92, State Route 35 and Lifemark Road intersections, which would have highly visible crosswalks to accommodate those traveling by bike, foot or horse.

Such an agreement would also include the addition of some sidewalks to connect the trail segments. That part of the project will have to be completed before people will be allowed unsupervised on the Southern Skyline Ridge Trail, according to environmental documents.

(Image via Yelp)

Another part of the project outside of the SFPUC’s control is how quickly other neighboring properties will build trails to connect with their new one. The Phleger Estate, which is part of the federal Golden Gate National Recreation Area but accessible only through San Mateo County’s Huddart Park, shows future plans to build a trail to connect with the new Southern Skyline Trail on its public trail map, but it is not clear yet when that will be built.

“When they’re ready, our trail will connect with theirs,” Ramirez said.

The expanded Fifield-Cahill Ridge Trail will offer a half-mile trail loop, a new 50-car parking lot and a new restroom along an existing part of the Bay Area Ridge Trail through Skylawn Memorial Park.

As with other segments of the Fifield-Cahill Ridge Trail, visitors in groups of up to 20 people will only have access while under the supervision of a trained volunteer docent to hike, bike or ride horses along the trail.

To sign up to access the Fifield-Cahill Ridge Trail with a docent, visit sfwater.org/trails. Upcoming docent-led events include hikes, bikes and trail runs of various lengths and from various starting points along the trail.


Stay up to date with other coverage from The Six Fifty by subscribing to our weekly newsletter, featuring event listings, reviews and articles showcasing the best that the Peninsula has to offer. Sign up here!

Kate Bradshaw

Kate Bradshaw

Bay Area reporter covering local government, inequality and the outdoors

You May Also Like

Outdoors experts reveal their favorite Peninsula hikes

How Pacifica Runners has carved community on the Coastside through Strava kudos and themed 5Ks

Back on the ranch: 10 Peninsula farms that are open to visitors

John Tarlton hunched over and covered with cups used for physical therapy.

Why a Palo Alto real estate CEO risked his life and marriage to find a cure for cancer