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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 the most difficult of the many routes that climb Skyline Ridge, and 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.

Despite being wooded, the lower portion of the trail gets very hot in the summer. The hike should be avoided if the high temperature for the day is forecast to be 85F or higher. In the winter the trail holds up remarkably well and doesn’t get muddy.

Click map to show all roads and trails
Map is part of the Bay Area Trail Map: Skyline Ridge (Redwood Hikes Press, 2017)

Hike description

Here’s the trailhead location in Google Maps.

The hike begins at a secret little parking lot that isn’t shown on the official park map. It’s on Rhus Ridge Road, off Moody Road a mile west of Highway 280. The lot is unsigned and not easy to find, but it only has twelve spaces and fills up quickly, especially when large groups show up. If the lot is full, park on the shoulder of Moody Road near Bledsoe Court; this adds 0.6 miles to the round-trip hike.

From the parking 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 this point there’s a 4-way intersection; turn right onto the wide singletrack trail. The singletrack is about a mile and a half long and 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 changes to a dirt road originally built for power line maintenance. At this point the woods end and the trail begins a steep climb through sunny chaparral. The dirt road isn’t as pleasant as the singletrack, but it does add variety to the hike and it also has the best views, with sweeping vistas of the South Bay and up the peninsula to San Francisco.

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 rise. 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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More information

The Black Mountain Trail


© 2010, 2012, 2013, 2017 David Baselt