The Black Mountain Trail

The peninsula’s biggest hill climb

Length 9.7 mi · Climbing 2420 ft
California > San Francisco Bay Area > Rancho San Antonio Open Space Preserve

The one level section of the Black Mountain Trail

This is both the most scenic and the most difficult of the many routes that climb Skyline Ridge. In fact, it’s one of the more challenging 10-mile hikes on the peninsula. The elevation change isn’t actually all that big for a hike of this length, but the long climb that gets progressively steeper toward the end has a way of wearing you out.

The trail is very popular and on a nice summer day you might encounter a group of hikers every five minutes or so. There’s an unusual variety of people here, with young and old, hikers and joggers, individuals and families, and a lot of Silicon Valley engineers all puffing their way to the top. The route seems to be a favorite of hiking clubs and other big groups.

The trail is really quite enjoyable; it’s surprisingly quiet and woodsy given that it overlooks the Bay Area, and it has the best views of Silicon Valley of any trail. There’s no traffic noise and few trail intersections, and much of the route is very well-maintained singletrack. The trail is mostly wooded, but there’s a long stretch of chaparral at the top.

Even through it’s wooded, the lower part of the trail gets very hot in the summer. The hike should be avoided if the high temperature for the day will be 85°F or higher. In the winter the trail holds up remarkably well and doesn’t get muddy.

The hike begins at the Rhus Ridge Drive parking lot. Due to complaints from local residents about the traffic, the parking lot is somewhat hidden; it was removed from the official park map, and no signs point the way to the lot. It only has seven spaces and is almost always full, and often someone is waiting for a spot to open up. No-parking signs festoon all the other roads in the area.

A sign helpfully suggests parking at Foothill College, although hardly anyone does, probably because it adds 1.7 miles round-trip and about a half hour to the hike. To get there, drive back to Moody Road and turn right. At the four-way Elena Road intersection, continue straight into Foothill College. Almost immediately, there’s a parking lot to the right. The sign at the entrance says “Public Parking”, but confusingly, every space in the lot is marked “staff”. Anyway, if you drive a few yards further, there’s a student lot on the left.

From the Rhus Ridge Road lot, a dirt road enters the woods, leads past a seedy-looking “caretaker’s house” with a horse corral, and then begins to climb steeply. After about a half-mile the first scenic view of the Bay Area appears. Even at this low altitude there’s already a pretty good view over Los Altos Hills.

The first mile of the trail features views of Los Altos Hills

At about one mile the road crests, entering an isolated, wooded valley. At the 4-way intersection, turn right onto the wide singletrack trail. There&rsqu;s about a mile and a half of singletrack, which is the best part of the hike. At first, the wide, well-groomed trail gives you a bit of a rest, remaining level as it winds around a canyon. After the Hostel Trail intersection, the trail narrows and begins to climb at a moderate grade through open woods. The woods are mostly oak and bay laurel and are quite attractive; the groundcover includes abundant small ferns, which is somewhat surprising in an area that’s so warm in summer. From time to time the trail passes through patches of chaparral with nice views of Rancho San Antonio’s heavily-wooded ridges.

The Black Mountain Trail

At about 3.5 miles the singletrack trail emerges from the woods onto a dirt road originally built for power line maintenance. The road isn’t nearly as pleasant as the singletrack; it’s steep and gravelly and climbs through chaparral that offers little shade. However, it has by far the best views of the hike, with dramatic, sweeping vistas of the South Bay.

The fire road section near the top of the trail has the hardest climbing but the best views

Reaching an antenna farm and a T intersection, turn right, then turn left onto Monte Bello Road. Climb the last few yards to the peak of Black Mountain, which is really more of a wide, gently-sloping knoll. There’s a cluster of small rocks and, for the first time, views of the rolling golden hills to the west with the conifer-clad Butano Ridge in the distance. The views to the east are limited by the flatness of the peak.

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The Black Mountain Trail


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