This ride is a hidden gem that will surprise most riders who aren't already aware of the existence of these trails. We're talking about a genuine mountain bike ride smack in the middle of San Francisco, 56% of which is on trails. More impressively, by my reckoning, 46% of the overall ride is actually on singletrack; often very juicy and secluded singletrack, and sometimes even fairly advanced singletrack. Anyone could be excused for not expecting to find such a ride in a place like this, both because San Francisco is the second densest major city in the US and because some of the best parts of this ride have only become available relatively recently (the trails on Mount Sutro were reopened in June 2011 after being closed to the public for the preceding 50 years).

The ride is in the form of trail rides in three small parks (Glen Canyon Park, Mount Sutro Open Space Reserve, and Mount Davidson Park) strung together via short road segments. Some other interconnecting trail segments along the way, which may be easy to miss unless pointed out, also add considerably to the overall singletrack total. My thanks to Hunter Sykes for helping me fill in many of the details of this route, as well as for waking me up to the full extent of possibilities for a San Francisco ride such as this in the first place.

It should be pointed out that this ride is all about directions. Many of the interconnecting trail and road segments that make up the ride will take plenty of attention and detailed instructions to follow the first time you do the ride, especially if you're not already familiar with this part of San Francisco. Things are made worse by the fact that, other than the part of the ride on Mount Sutro trails, none of the trails on the ride are named or signed. If you'll be able to take a GPS with you to which you can upload the GPS track on this page and follow it along as you ride, you'll be in the best shape you can be. The rest of you can find some descriptions of the tricky bits of the ride in the text below, but the most detailed written directions for the ride are in the captions of the ride's photo set (along with plenty of visual cues that should help you, of course).

One important warning I have regarding this ride is about weather. Anyone local to the city can tell you that the area around Twin Peaks, where this ride spends most of its time, holds some of the most notorious neighborhoods of the city in terms of being foggy, chilly, and blustery, even on days when other parts of the city can be sunny and comparatively balmy. So, you should adjust your expectations of temperature (as well as the availability of any of the gorgeous views) accordingly. For that same reason, I understand that many of the trails on this ride are surprisingly prone to being wet and muddy when you least expect it, due to fog condensing on foliage and dripping to the ground. I was given the impression that these trails can be a real pain when they're wet (not to mention the potential harm to the integrity of the trails if they're ridden while in that condition). So, don't expect this ride route to be good to go simply because there have been no rains for a while. Let me put it this way: I did this ride on a sunny September day arriving on the heels of a few more sunny days, when the most recent rains were months ago, and a few trails still had multiple muddy spots. For picking a good day for this ride, I would say that your best bet will be in the fall.

The weather consideration, or more accurately the trail condition consideration for this ride deserves some extra emphasis. See the reader comment left by Alex below in order to get a sense for the significance of this. Since I've originally posted this ride, I've encountered comments in online forums and group ride sites more than once about plans to do this ride merely a couple of days after the last rain. The warning against riding these trails in bad conditions isn't merely to save the rider from some discomfort. It's an appeal to ensure the integrity and the sustainability of some of these trails themselves. So, please, do not do this ride unless you're certain that the conditions will be perfectly dry.

Many who live in the city should be able to start this ride right from their doorstep. While parking within San Francisco is known to be challenging, those of you who'll have to drive there to do the ride may still find parking available in multiple areas along this route. Some of the possibilities I'd consider as alternatives to the suggested parking spot linked on the left would include Clarendon Avenue, Dalewood Way, and possibly any of the side streets traversed on the ride, though you should make sure to check the signs for any limitations. The spot on Bosworth Street at the Suggested Parking link is a particularly suitable spot not only because it's so close to Glen Canyon Park, but also because one side of the street there features an extra-wide lane seemingly built with parking in mind and four hours of free parking is allowed. In addition, that block was almost deserted when I started this particular ride around midday on a beautifully sunny and warm Saturday.

Easily the most questionable part of the ride is the portion in Glen Canyon Park. Despite the fact that none of the trails in the park are closed to bikes as far as I can see, the park is not very friendly to mountain bikers. The reason is the nature of the trails. Most of the higher trails along the northeastern slopes of the valley in the park are little more than treacherous goat paths that seem to be really only meant for hiking. You'd have to be a world-class trials rider to be able to traverse some of them on a bike. That only leaves a couple of alternate paths that follow the creek bed in the park as suitable options for bikes, and the singletrack portions of even those trails are interrupted by some super-tight turns and numerous chest-height tree limbs (sometimes even handlebar-height ones!). Meanwhile, the few busiest trails of the park, closer to its southeastern corner, are reminiscent of wide gravel landing strips. If I were to do this ride over again, I'd consider leaving Glen Canyon Park out of the ride route, but I think it's good that I've included it on this particular ride route, at least as a cautionary tale.

You leave Glen Canyon Park through a concrete path with some stairs that connect to Turquoise Way between private homes. The first obscure shortcut path that you use on this ride arrives when you pedal up this street and turn left onto the dead-end side of Amethyst Way. A very short dirt trail starts at the end of the street and cuts through a small empty lot to reach Portola Road. This marks the beginning of a sizable road segment on the ride that will take you all the way to Mount Sutro. The idea behind the route I followed here through back streets was to reduce unnecessary elevation change as much as possible, in addition to staying away from traffic. If you prefer, you can take Portola Road to Twin Peaks Boulevard and follow that to Mount Sutro instead, effectively traversing in reverse the same path that you'll take through those parts in the second half of this ride. Along the way, you can also take the same shortcut trails followed on this ride in both directions, thereby increasing the singletrack content of the ride even further. You'll also be boosting the ride's scenery score.

When done in the way shown here, the ride reaches its second obscure shortcut trail at another dead-end, this time the one on Mountain Spring Avenue. This partially overgrown narrow path descends somewhat steeply to Clarendon Avenue in just a couple of hundred feet. I should warn you, though, that as I did this ride, some of those bushes I had to brush past on this trail were quite thorny. Consider walking your bike down this shortcut if you're not willing to suffer some scratches.

A little more pedaling on the road and a right turn onto Johnstone Drive brings you to the trailhead of Fairy Gates Trail where the fun on Mount Sutro begins. Fairy Gates Trail is a narrow and short singletrack. Like most other trails in this park, it traverses an improbably lush forest setting. In one or two spots, it holds trail features that could be of black-diamond difficulty level.

Fairy Gates Trail quickly connects you to a series of switchbacks on North Ridge Trail, to which you'll return one more time on this ride. On the first time, you descend this section down to the somewhat confusing multi-way junction at its bottom, and follow the leftmost trail at that junction to cross Medical Center Way shortly and get started on Historic Trail. This trail is a medium-width singletrack that winds all the way around this hill as it climbs toward the peak at a moderate slope, not exceeding 10% grade by very much. It's not a technical trail at all. This trail is the one whose surprise discovery has led to all the stories you may encounter about a forgotten trail network being rediscovered on Mount Sutro. We owe the rehabilitation of this historic trail and the existence of all the other ones in this park to the Sutro Stewards volunteer group.

When Historic Trail reaches the southern tip of the trail network of this park, you'll come to another confusing multi-way trail junction. Here, you'll be faced with a very short optional singletrack side loop and a couple of alternate ways of reaching the summit of the hill, along with one option that doesn't lead up there. This ride's route does a quick clockwise traversal of that tiny singletrack side loop first (a sweet and narrow trail that weaves very tightly through some young eucalyptus trees) after which it follows what was the sharp left turn onto the leftmost trail when you had originally reached this junction, to follow the narrower (unnamed) trail option that leads to the summit. This unnamed singletrack is a tight and twisty one and is on the technical side as it climbs (occasionally pretty steeply). This also happens to be the wettest trail segment I encountered on Mount Sutro while doing this ride. It had multiple unavoidable muddy spots, which were soft enough to cause traction problems.

When this short and juicy singletrack deposits you onto the wide fire road that's Nike Road (taking its name from the Nike missile base that used to be here), you're almost at the top of the hill already. Heading further uphill will take you past a trail map board at which you'll be faced with some forks in the trail. Pick the right-hand option of any choice with which you're presented here, and you'll quickly end up back on singletrack on East Ridge Trail. As you follow this trail to Mystery Trail and that one to North Ridge Trail, despite encountering a rock garden or two along the way, most of the descent is a gentle, non-technical singletrack ride through a surprisingly pristine looking urban forest.

You emerge from Mount Sutro Open Space onto Stanyan Street once again through a pathway between two homes that ends with a flight of stairs. You head uphill on this steep but very brief street segment of the ride on Stanyan Street, and as soon as you turn right onto the dead-end side of Belgrave Street, you pick up another tight little shortcut trail almost before pedaling for any distance at all. This singletrack, labeled as "Belgrave" on the Mount Sutro PDF map linked on the left, is a very narrow and very steep one. If you have championship-level downhill riding skills, it might be worth trying your hand at riding downhill on this short trail segment in an alternate version of this ride, but most riders will have to walk this trail whether climbing or descending it. There are also something like three unsigned forks along this trail. Any wrong turn should become fairly obvious quite quickly, but in case you'd like to keep track, the correct turns to take are "right, right, and left". (Note that the current version of that Mount Sutro PDF map has replaced the shortcut followed here with a label that reads "Not maintained". If you can't make it through the way that is described here or would rather not try, simply following 17th Street to Clayton Street and then taking Clarendon Avenue all the way up from there wouldn't be such a bad detour either, would cost you only a few dozen extra feet of elevation gain, and would actually result in a gentler climb overall.)

This will bring you back to Johnstone Drive. Take that street to Clarendon Avenue, turn uphill (right) and try not to miss the beginning of Dellbrook Street that will arrive very quickly on the opposite side of the road. You'll follow this one, do a left turn onto La Avanzada Street very shortly, and pick up an unsigned and easy-to-miss trailhead on the right in order to start the next singletrack segment of the ride. This trail will take you around Sutro Tower and up to the covered Twin Peaks Reservoir. This trail segment also shares top honors for being one of the wettest on this ride. It's a pretty technical trail that's frequently surprisingly narrow, and also unpleasantly off-camber in many places unfortunately. When you arrive at the reservoir on this trail, at the base level of the tower, don't be confused: You need to follow the continuing trail through the bushes toward your right. This remaining singletrack section will carry you to Marview Way and then straight across it to reach Twin Peaks after another couple of shortcut trail segments.

Twin Peaks is obviously one of the best spots from which you can take in views of San Francisco. So, be prepared to devote some time to enjoying the view and taking some photos (assuming the marine layer allows it), unless you've done this ride umpteen times before. You're likely to need to weave through a tourist crowd as you make your way southward through the vista point's parking lot. When you leave the parking area behind, you'll find a path that starts following on the outer side of the low wall along the bay-side half of Twin Peaks Boulevard. On this ride, you take that path and follow it past the two peaks that are the "Twin Peaks", followed by taking two other minor shortcut trails on your way down Twin Peaks Boulevard back to Portola Drive.

Your half-mile coast down Portola Drive on the way to Mount Davidson will probably be alongside some heavy traffic, unfortunately, as well as ending in a tricky left turn that requires you to cross traffic and utilize a turn lane. Thankfully, that will be your only adventurous brush with heavy traffic on this ride. A quick succession of what might be confusing turns through some side streets will soon have you climbing the very steep Dalewood Way on your way to Mount Davidson Park. The grades here hover above 20%, so it's likely to be another short hike-a-bike for mere mortals. As you make your way up this street, you'll notice a trailhead that enters the park earlier than the one this ride route uses. This is a valid alternate route. If you enter the park there, you'll essentially be taking the same singletrack trail uphill toward the peak that this ride route follows downhill on the way back from it. It's actually recommended and would increase your trail mileage. The route plot shown here, however, enters the park after the end of the climb on Dalewood Way, through a fire road that reaches the peak more directly. The only reason for that is that this ride was my first time riding on Mount Davidson and I didn't know what to expect from the trails starting from that lower trailhead, so I wasn't too open to taking chances.

Atop Mount Davidson, you'll find the 100-foot-tall "Sunrise Easter Cross" that's the site of an Easter morning outdoor religious service every year, and whose sight you may have glimpsed from various other viewpoints in the city before. This hilltop is also the tallest peak within the city of San Francisco, though its official height exceeds that of Mount Sutro only by about 20 feet. This ride quickly visits the cross, takes in the views from a clearing near the peak that presents better sightlines toward San Bruno Mountain compared to those from Twin Peaks, and then starts heading back down. On the way down, you take a little more than a half loop around the hill on a singletrack. Initially, this trail is bare, narrow, and quite sketchy in a number of spots. Before long, though, it stabilizes as it enters initially a patch of chaparral, and then forest cover. It becomes a fairly smooth and comfortable—though still narrow—forest singletrack and glides back to San Francisco streets.

On your way back from Mount Davidson, you retrace your steps along Portola Drive and follow it to the same brief shortcut you took through an empty lot to reach it from Amethyst Way. As you continue down Turquoise Way the same way you came up, look for the same stairs that enter Glen Canyon Park. They're easy to miss, so it could help to remember that they're adjacent to a home on that street with door number 48. Upon re-entering Glen Canyon Park, I've tried following an alternate route to the other end of the park, but I ended up on one of those goat paths that are higher up. The first eighth of a mile or so of the route past the first split after re-entering the park is essentially a series of brief rock scrambles on a narrow cliff-side path. The route then connects back to the "main trail" along the creek bed in the park and quickly merges onto the ultra-wide gravel path that leads back to the picnic and recreation areas at the southern tip of the park and back to the parking spot. When I do this ride again, I'll simply follow the reverse of the path I took through the park at the beginning of the ride. Regardless of how many tree limbs block your way, it's still better than carrying your bike over a bunch of cliff's-edge boulders. That is, if I include Glen Canyon Park on this ride the next time at all.

The trails traversed on this ride are not necessarily the only surprising bits of urban singletrack you can find in San Francisco. There are additional stretches in some other parks in the area such as Stern Grove and Buena Vista Park, not to mention a whole host of trails in Golden Gate Park (though the legality of most trails in Golden Gate Park for bikes is questionable at best). However, I feel that you'll find yourself adding a growing amount of street mileage to your ride for the sake of smaller stretches of additional singletrack if you go after other legitimate bits of trail segments in the area.