In its first month, the Skyline Watershed Ridge Trail drew more than 20,000 visitors, according to rangers quoted by ABC7. All of them came through one parking area on Highway 35, just south of the Highway 92 intersection. It has 22 standard spaces, five trailer spaces and two accessible spaces.
The trail itself is six miles of wide crushed rock running south along the ridge above Crystal Springs Reservoir, with views out to the Pacific and across the Bay. For anyone driving up 92 from Hillsborough, the trail is the easy part. The trailhead is what takes planning, and so does the way the route is laid out.
One gate, in and out
The San Francisco Public Utilities Commission built the trail on its Peninsula Watershed land and opened it on August 24, 2026. It added nearly six miles to the Bay Area Ridge Trail. It is an out-and-back route with "no outlets or connections to neighboring park sites." It ends at the Phleger Estate boundary, so a full visit is 12 miles round trip, starting and ending at the same lot.
That layout is what makes parking the pinch point. Every hiker, runner, cyclist and equestrian leaves from the same gate and comes back to it, so a parked car stays put for as long as its owner is on the ridge.
ABC7 reported on September 28 that the lot fills quickly on weekends. When it does, some visitors park along Highway 92 and Skyline Boulevard and walk across to the trail. The SFPUC's own trail page says there is no dedicated crossing of Highway 35 or 92. It asks visitors to follow posted parking rules, keep gates and access routes clear, and avoid parking in vegetation, which it calls a fire hazard.
The same ABC7 story quoted Will Roberts and Dmitry Elperin, co-owners of the historic Mountain House restaurant on Skyline Boulevard in Woodside. They said they welcome the extra business hikers and cyclists bring but worry about people crossing the road. "As I drive to work and turn off 92, I've seen some hairy moments," Elperin told the station. San Mateo County Supervisor David Canepa put it as a question of "how do you deal with success?" ABC7 noted that parking restrictions or other safety changes were possible, but none had been announced as of that report.
The climb is almost all on the way out
The crowding has a second cause, and it's the elevation profile. The trail starts at its low point by Highway 92 and climbs as it heads south. According to the SFPUC, the route has a net elevation change of about 1,200 feet from north to south.
| Direction | Elevation gain | Elevation loss |
|---|---|---|
| Outbound, trailhead south toward Phleger Estate | About 1,500 feet | About 300 feet |
| Return, back north to Highway 92 | About 300 feet | About 1,500 feet |
The return figures are the outbound numbers reversed, since it's the same path. The running slope ranges from 6 percent to a maximum of 23.5 percent. The press release describes level stretches and gentle grades for easier walking and cycling, plus steeper hills and curves for anyone who wants more of a challenge.
This matters for planning. Your turnaround point sets how much climbing you do, and the hard work comes first while the easier miles come last. Someone who turns back at mile 2 skips most of the gain. Someone heading for the Phleger boundary does the full climb before the downhill trip home. Either way, the clock starts when you park and stops when you're back at the same space.
Supplies follow the same layout. Vault toilets sit near mile markers 2 and 5 and can only be reached from the trail. There is no restroom at the trailhead, no potable water on the trail, and no picnic tables or trash cans, so everything gets packed out. Mile markers help you track distance, and ten interpretive panels along the way cover the watershed's plants, wildlife and history, along with its role in the Hetch Hetchy Regional Water System.
What the permit and the gate ask of you
The rules are simple, but a few of them catch people who arrive unprepared:
- Permit. You need a free annual permit, which you can get through the SFPUC's online application. Permits work right away, are valid for the calendar year, and cover groups of up to six people.
- Proof. You don't have to show the permit at the lot or put it on your dashboard. Watershed staff on patrol may ask whether you enrolled, and an email confirmation or a screenshot counts as proof.
- Hours. The trailhead gate and parking lot are open daily from 6 a.m. to 6 p.m. The FAQ lists no separate winter schedule.
- Dogs. Dogs aren't allowed, to protect the watershed's natural resources and water quality.
- Bikes. Motorized vehicles are banned, including electric bikes and scooters. The SFPUC recommends mountain-capable bikes on the crushed-rock surface.
- Weather. The FAQ warns that conditions on the ridge can shift from hot to cold and windy.
The calendar-year permit works out differently depending on when you sign up. A permit issued this week covers the rest of 2026, ten weeks or so, and you'll need a new one for 2027. Anyone who first gets a permit in January gets a full year of visits out of it.
The 6 p.m. closing time is the other thing to watch. On a full 12-mile round trip, much of the climbing comes in the first half. A late-afternoon start gives you less time on the ridge before you need to be back at the car.
When the lot is full
The trail's popularity has an upside. The Peninsula Watershed has other ways in, and some of them are close to the same intersection.
North of Highway 92, the SFPUC also runs the 10-mile Fifield-Cahill Ridge Trail on watershed land. Next to it, as part of the same project, the agency built the Watershed Discovery Trail. It's a half-mile route designed for visitors of all abilities, located just north of Skylawn Memorial Park. Its interpretive panels include tactile three-dimensional models of watershed wildlife for visitors who are blind or have low vision, and visits run as guided outings with trained docents.
Down on the reservoir side, San Mateo County Parks lists the Crystal Springs Regional Trail at 15.3 of a planned 17.5 miles. Its Sawyer Camp section runs from Hillcrest Boulevard to Crystal Springs Road. One stretch is affected this fall. The county's October 13 advisory says the north San Andreas section is closed through Monday, November 2, while the SFPUC repairs a broken water line. The closure runs from the gate off San Bruno Avenue to an electric gate half a mile south. County Parks says the regional trail is otherwise open year-round, including holidays, subject to posted advisories.
A layout that may not stay this way
The one-entrance setup that drives today's parking pressure is part of the current design, and the plans go further. The SFPUC says a connection to the Purisima Creek Redwoods Preserve North trailhead is in the planning stages, and it directs questions about that link to the Midpeninsula Regional Open Space District. A second way in at the south end would change how visitors spread out along the ridge. For now, no completion date has been published.
Parking is still unsettled too. As of ABC7's September 28 report, county leaders were willing to work with the SFPUC on solutions, but no changes had been announced. Before you head up 92, check the SFPUC's trail page for current conditions. The agency takes questions at [email protected].
I keep track of how new trails, road work and local landmarks shape weekends in Hillsborough. If you'd like to talk about life in town, or about the neighbors and spots that make it home, Filipina Opena is always glad to hear from you. Let's Connect.
