If heavy fog won't keep people away, what will? On Saturday, September 19, the San Francisco Chronicle reported, fog sat over the Peninsula Watershed and the Skyline Watershed Ridge Trail's parking lot was still full by 7 a.m.
The trail opened August 24, 2026, at the top of Highway 92. It is the first self-guided public route through the San Francisco Public Utilities Commission's 23,000-acre Peninsula Watershed. According to the Bay Area Ridge Trail Council, this corner of the watershed had been closed to the public for more than a century. Most coverage has been about the views, and the views are as good as promised. For anyone in San Mateo, though, the useful thing to understand is how the trail is set up. Getting permission to hike is easy and unlimited. Getting a parking space is the hard part. Because of that, hikers who live a short drive down 92 and can pick their day have an advantage.
One Way In, the Same Way Out
The trail has a single entrance, and most of its limits follow from that. The trailhead is on Skyline Boulevard, also called Highway 35, about a tenth of a mile south of the Highway 92 junction and just past Skylawn Memorial Park. Heading south, the lot is on your left. From there the trail runs six miles south to the Phleger Estate boundary and ends. You come back the way you went, for 12 miles round trip.
The Mercury News reported that a fence separates the trail from Skyline Boulevard the whole way. You can't join it from the road partway along, and you can't leave it early except by turning back.
| Detail | What the SFPUC lists |
|---|---|
| Length | 6 miles one way, 12 miles round trip |
| Elevation gain | About 1,500 feet, north to south |
| Surface | Six-foot-wide crushed rock, with level stretches and steep sections |
| Hours | Daily, 6 a.m. to 6 p.m. |
| Parking | 22 standard spaces, 5 trailer spaces, 2 ADA spaces |
| Restrooms | Vault toilets near mile markers 2 and 5, none at the trailhead |
| Drinking water | None |
| Allowed | Hikers, runners, non-motorized bikes, horses |
| Not allowed | Dogs other than service animals, e-bikes, scooters, drones |
Along the way the trail passes grassland, wetlands, coastal scrub, Douglas fir, and redwood groves. It has views of the Pacific, San Francisco Bay, and Crystal Springs Reservoir, plus ten interpretive panels about the watershed's role in the Hetch Hetchy Regional Water System. When the 2021 plan was approved, the lot was described as 20 cars. It opened with 22 standard spaces, plus trailer and ADA spaces. That's a small lot for a six-mile segment that brought the regional Bay Area Ridge Trail to 413 miles.
A Permit That Doesn't Limit Anyone
The permit is free, and it doesn't cap how many people can come. Here's how you get one:
- Go to sfpuc.gov/trails. It takes you to the SFPUC's RecDesk portal.
- Create an account or log in, then enroll in the permit "membership." It costs nothing; "membership" is just how the portal is set up.
- Sign the forms and check out. The permit works right away and lasts through the end of the calendar year, so you don't apply again for each visit.
The SFPUC's FAQ says there's no limit on the number of permits issued, nobody checks permits at the entrance, and staff on the trail may ask whether you registered. The Chronicle noted you can even register at the trailhead. In practice, the permit is a way to sign people up for the rules. It doesn't control how many show up.
According to the FAQ, you don't need a physical permit, and an email confirmation or a screenshot of your enrollment counts as proof. The printed 2026 permit also says to carry a copy or a screenshot. Party size is less clear. The FAQ says a permit holder can bring six guests, while the RecDesk listing describes a permit as covering up to six people. A screenshot on your phone and a group of about six or fewer meets both versions.
The permit listed in the portal right now runs from 8/24/2026 to 12/31/2026, and no 2027 permit is listed yet.
What Happens When the Standard Spaces Run Out
Because the permit doesn't limit numbers, the parking overflow lands on two state highways. On Saturday, September 12, The Almanac saw a line of cars on the shoulder of Skyline and visitors, children among them, crossing the highway through traffic to reach the trailhead. Neither road has a marked crosswalk. The same report said the CHP lists the speed limit on Highway 92 at 55 mph.
This crossing was a known issue from the start. In 2021, The Almanac reported that the project's environmental review called pedestrian conditions at the 92 and 35 intersection a "significant and unavoidable" impact. The SFPUC planned to work with Caltrans on one of two fixes: a bridge over Highway 92 or a roundabout with highly visible crosswalks. Today the SFPUC's trail page says plainly that there is no dedicated crossing of either highway.
San Mateo County Supervisor Ray Mueller wrote to the SFPUC about parking past the shoulder line, people walking along and running across the road, cars parked in vegetation, and litter. He also praised the project. As he told the Chronicle:
"They did an amazing, wonderful thing by investing in this trail. We just need a little bit of modification because of how many people want to enjoy it."
Mueller suggested permits could name a date and time of day. The Chronicle reported that the CHP hadn't issued citations, partly because the area around the lot has no "no parking" signs. The CHP is working with Caltrans on whether and where signs would help. Caltrans told The Almanac that its traffic safety staff were assessing the area and that nothing had been finalized. In ABC7's September 28 report, no changes had been announced. We haven't found any reported signs, enforcement, or permit changes since then.
The Older Watershed Trail Limits Numbers by Design
North of Highway 92, the SFPUC runs a different system on the 10-mile Fifield-Cahill Ridge Trail. You can't hike it on your own. Visits are docent-led outings on Wednesdays, Saturdays, and Sundays, with reservations required and groups capped at 20. On that trail the reservation sets the headcount before anyone drives up the hill. On the new trail, the parking lot is the only thing that sets it.
A Press Democrat guide published during opening week said Fifield-Cahill outings were paused for August and September and would resume with booking through the SFPUC. The same project added the half-mile Watershed Discovery Trail next to Fifield-Cahill. It's accessible to visitors with disabilities and has tactile three-dimensional wildlife models for visitors who are blind or have low vision. Access is through docent-led outings. If a full lot on the south side of 92 ends your Skyline plans, these reservation-based options across the highway are the backup that comes with a guaranteed spot.
Timing a Visit This Fall
The SFPUC's own advice is to come on a weekday and, if the lot is full, go somewhere else. Mueller and others told the Chronicle that weekdays or bad-weather days may be the best fix for now, and that crowds may thin once the trail is less new. Both pieces of advice favor people who live close by. San Mateo hikers can drive up 92 on a Tuesday afternoon, check the lot, and still have time for another plan if it's full.
The next few weekends will put more traffic on 92. The 54th Half Moon Bay Art & Pumpkin Festival runs October 17 and 18, 9 a.m. to 5 p.m. Main Street closes from Mill Street to Monte Vista Lane, and people leaving the festival can't turn onto eastbound Highway 92 from Main Street. KQED passed along organizers' tips, including arriving early, staying through dinner so you aren't leaving around 5 p.m., and using Highway 84 as an alternate. Both the festival traffic and the trailhead traffic use the 92 and 35 junction, so a weekday hike that week means skipping both.
The gate is open 6 a.m. to 6 p.m. every day, and the SFPUC hasn't posted any winter hours. If a car is still inside after 6 p.m., it can leave using the gate sensor or button. The SFPUC says it emails permit holders about closures and planned maintenance, so your registered inbox is where any rain closure will be announced. The SFPUC Commission meets October 13. Its agenda includes a construction contingency item for the Southern Skyline Boulevard Ridge Trail Extension and nothing on parking or permits. A connection south to Purisima Creek Redwoods Preserve is planned, and the Ridge Trail Council says it depends on a safe crossing of Highway 35.
At Watson Marshall Group, we pay attention to how projects like this trail shape San Mateo life, because things like weekday ridgeline hikes become part of the story we tell when a home goes on the market. If you're thinking about selling and want to know how your home's location and daily routines show up in its value, request a home valuation and we'll go through it with you.