On May 13, 2026, the County of San Mateo cut a ribbon at the day-use area of San Bruno Mountain State and County Park, at 555 Guadalupe Canyon Parkway. The occasion was a new set of picnic areas and a loop trail, the kind of quiet infrastructure work that rarely gets a ceremony. This one did, and the county brought along Danny Chui, now principal of John F. Kennedy Elementary School on the mountain's west slope, who talked about growing up nearby and how the mountain was one of the few free things his family had to do when he was a kid.
That same week, a few miles away on the other side of the same ridge, a different conversation was happening about the same mountain, and it wasn't about picnic tables. Since 2025, a developer called Orchard Partners has been making the case to the city for something considerably larger: closing the Guadalupe Quarry, the working rock pit that's been mined for decades, and building a 1.3-million-square-foot advanced manufacturing complex in its place.
Both of these things are true at the same time, on the same mountain, and if you live in Brisbane, you're the one who gets to watch both play out from the same trailhead.
What the county actually built
The new day-use improvements sit at the main park entrance off Guadalupe Canyon Parkway, and they're designed to do something simple: give people more reasons to stop and stay rather than just pass through on their way up. New picnic areas mean groups can gather without hunting for the one shaded spot that already exists. The loop trail gives families with young kids or anyone who doesn't want a 1,300-foot climb a way to actually use the park without committing to the ridge.
That distinction matters more than it sounds. San Bruno Mountain's reputation, at least among people who've hiked it, is built almost entirely on its harder routes. The mountain earns that reputation honestly.
- Ridge Trail and Quarry Road Loop: 3.4 miles, 1,328 feet of elevation gain, rated a hard hike by most trail databases and popular with hikers, trail runners, and mountain bikers alike. Dogs are allowed on leash.
- Summit Loop Trail and Ridge Trail: the steepest combination on the mountain, with 1,692 feet of elevation gain leading to the 1,314-foot summit. Along the way you'll pass habitat for the Mission Blue butterfly, plus California poppies and sticky monkeyflower lining the informal sections of trail.
- Quarry Road Trail: starts at the intersection of Inyo Street and San Francisco Avenue, where there's a community garden and picnic benches before the climb even begins. The first stretch runs on Inyo Street itself, closed to vehicles. Past that, Quarry Road widens and runs along the edge of the San Bruno Mountain Ecological Reserve, which the California Department of Fish and Wildlife maintains as one of the state's better remaining patches of native chaparral and grassland, including the Buckeye and Owl Canyon sections.
None of these routes are new. What's new is the reason to start your visit at the bottom instead of driving straight to a trailhead: the picnic areas give the park an actual front door.
The quarry most trail guides don't mention
If you've hiked Quarry Road, you already know there's a working quarry at the end of it. Trucks use the road occasionally, and the pit itself sits behind a gate. What most descriptions of the trail leave out is that the quarry's future has been an open question in Brisbane for most of the past year.
The basics: the Guadalupe Quarry has historically supplied materials to Highway 101 and San Francisco International Airport, and mining there has slowed considerably since 2020, though the San Mateo Daily Journal reported in July 2025 that there's still enough aggregate on site to mine for roughly another 20 years at current pace. This isn't the site's first brush with redevelopment. Brisbane residents rejected a proposal to build housing there back in 2006.
The current proposal is different in kind. Orchard Partners wants to close the mining operation entirely and build what it calls the Quarry Innovation Center, an advanced manufacturing facility that would annex about 104 acres into city limits. Of that, the company has offered 36 acres as a permanent conservation easement and another 46 acres to the county as public open space. The pitch includes up to 1,500 jobs.
"I really look at it through a lens of sustainability."
That's Brisbane Mayor Cliff Lentz, quoted in the same Daily Journal report, weighing environment, equity, and economics together and declining to get ahead of a project that hadn't yet come before the council. The opposition has been more direct. San Bruno Mountain Watch has argued the site provides habitat for three federally endangered butterfly species, the Mission Blue, the Callippe Silverspot, and the San Bruno Elfin, and has questioned whether the conservation offer actually restores land that's been mined for decades rather than simply setting aside what wasn't buildable anyway. The group hosted open houses and a quarry viewing walk in April, May, and June of 2025, and the Daily Journal reported the council was expected to take up the final environmental review in early 2026.
If you hike Quarry Road regularly, this isn't background noise. It's the same gate you walk past.
Down at the water, a quieter version of the same idea
Brisbane's other outdoor identity runs along the water rather than up the ridge. The Bay Trail picks up at Brisbane Lagoon, a body of water that was an open cove before Highway 101 was built through it and still supports enough bird and fish life to be worth the stop on its own. From there the trail runs past the Brisbane Fishing Pier to Brisbane Marina, a 567-berth harbor the city owns and operates, funded by berthing fees rather than general tax dollars. The marina includes a picnic area, a par course, and the Sierra Point Yacht Club at its edge.
If you'd rather stay on land, the Crocker Park Recreational Trail loops around the businesses at Crocker Park on a gravel path that used to be a Southern Pacific Railroad right-of-way. It's flat, it's short, and it sits directly across from the Brisbane Dog Park, which makes it one of the more practical loops in town for anyone whose actual hiking partner has four legs.
Old Town, after the hike
Visitacion Avenue does double duty as Brisbane's commercial spine, and two of its longest-running businesses are worth knowing if you're new to the habit of ending a hike with a stop downtown. The Brisbane Inn, at 50 Visitacion Avenue, opened in 1938 and has stayed in the same family for generations, which in a town this size counts as institutional memory. A few blocks down, Midtown Market at 249 Visitacion Avenue keeps grocery hours that run into the night, which matters more than it should when you've timed a hike badly and need something before the kitchen closes at home.
Neither business shows up in the coverage of San Bruno Mountain, and neither one needs to. They're just where the mountain lets out.
The same mountain, moving in two directions
What makes this moment in Brisbane worth paying attention to isn't the quarry fight by itself or the new picnic tables by themselves. It's that both are happening on the same landmass, in the same year, and the way each one resolves changes what the mountain looks like from your front door. A resident walking Quarry Road this month is standing between a freshly funded public investment on one side and an active development proposal on the other, and the two aren't in separate parts of town. They're on the same trail.
That's not a reason to hike differently. It's a reason to keep an eye on what the county and the city actually do next, because on a mountain this size, the changes tend to show up in the view before they show up anywhere else.
If you're the kind of neighbor who already has an opinion about Quarry Road, or you're still working out which loop suits your Sunday pace, we'd like to hear about it. Watson Marshall Group spends as much time paying attention to what's actually changing in towns like Brisbane as we do talking about home values, and we're always glad to talk through either one.