Black Mountain Trail,
Rancho San Antonio Open Space Preserve,
Midpeninsula Regional Open Space District,

Santa Clara County
In brief:
9.4 mile out and back to the top of Black Mountain. Mostly easy, but the last mile to the top is very steep.

Distance, category, and difficulty:
This 9.4 mile out and back hike is strenuous, with over 2300 feet of elevation change. Trailhead elevation is about 500 feet, and the elevation at Black Mountain is about 2810 feet. The first 3.3 miles are easy, but the last 1.2 miles to the summit are grueling.

Mostly exposed.

Trail traffic:

Trail surfaces:
Dirt trails and fire roads.

Hiking time:
5 hours.

Not for summer -- pick a cool day.

Getting there:
From Interstate 280 in Santa Clara County, exit #16 El Monte/Moody Road and drive west on Moody Road. Go straight through the stoplight at Foothill College, and at a stop sign at about 0.6 mile, turn left to remain on Moody. Drive about 0.5 mile more on Moody, then turn left onto Rhus Ridge Road. Drive about 0.2 mile on this narrow road, then bear right into the parking lot. 

Get driving or public transit directions from Transit and Trails:

GPS Coordinates* for Trailhead:
Latitude 37.352176"
(* based on Google Earth)

Trailhead details:
This trailhead has parking for about 12 cars; no parking on Rhus Ridge Road. No entrance or parking fees. No toilet facilities or drinking water. No designated handicapped parking, and trails are poorly suited to wheelchairs. Maps available at information signboard. There is no direct public transportation to the trailhead, but Santa Clara County's VTA buses service Foothill College, about 1 mile from the trailhead: visit the Transit Info website for details.

Gas, food, and lodging:
There are no facilities in the immediate area -- gas, stores, restaurants, and pay phones are a few miles to the north or south off 280. Camping is not permitted in Rancho San Antonio, but Monte Bello has a small backpacking camp open by advance reservations only, near the top of Black Mountain.

Park is open from sunrise to 1/2 hour after sunset. Most Rancho trails, including Black Mountain Trail, are designated hiking and equestrian only. In the eastern section of the park a few trails are open to hikers and cyclists only, and there are a handful of hiking only trails. Dogs are not permitted anywhere in the preserve.

The Official Story:
MROSD's Rancho page.
MROSD field office 650-691-1200

Map Choices:
• Use AAA's San Francisco Bay Region map to get there.
Map from MROSD (download the Rancho San Antonio pdf). If you decide to go all the way to the summit of Black Mountain, the Monte Bello map is also useful.
Peninsula Tales and Trails, by David Weintraub (order this book from has an overview of the preserve, descriptions of hikes, and simple maps.
Afoot and Afield: San Francisco Bay Area, by David Weintraub (order this book from has a great map and descriptions of a Rancho hike.
• The Trail Center's Trail Map of the Southern Peninsula  (read more about this map at includes Rancho San Antonio and surrounding preserves, but the mileage figures for Black Mountain Trail are underestimated.
• Tom Taber's The Santa Cruz Mountains Trail Book has a map and preserve description (order this book from
Peninsula Trails, by Jean Rusmore, has a simple map and trail descriptions (read more about this book at
Read Bay Nature's article about Rancho San Antonio

Black Mountain Trail in a nutshell -- a printable, text-only guide to this hike.

View photos from this hike.

Go to Bay Area Hiker Home page

This 9.4 mile out-and-back hike to the top of Black Mountain has two very different segments. Trailhead Although the first mile, on Rhus Ridge Trail, is a bit steep, the initial stretch of Black Mountain Trail is a nicely graded footpath winding through woods and chaparral. Then suddenly, 3.3 miles up the mountain, the footpath widens to fire road width, and shoots nearly straight uphill, with little shade. The ascent is worth it, for the amazing views at the top and the feeling of accomplishment -- an over 2300 foot climb all the way up the mountain!
     The trip to Black Mountain is great in spring when a variety of vegetation is in bloom, and temperatures are cool. It's not bad in winter either, although the trails can by muddy if horses have been on them soon after rain (MROSD occasionally closes the trail to horse traffic in wet months). Summer is the least appealing, simply because the parching hot sun intensifies the push to the summit. Especially in warm weather, be sure to bring lots of water. Rhus Ridge Trail On my August trek I sucked down 3 liters of water, and still ran out before the end of the hike.
     Begin at the Duveneck Windmill Trailhead on Rhus Ridge Trail. The first stretch of this broad trail, open to hikers and equestrians, is a level meander along a canyon floor. You'll pass the caretaker's house and go through another gate, then begin a slight climb. California bays and coast live oaks give way to chaparral as the trail sweeps uphill to the right, the grade stiffening a bit. Deer are common in this part of the preserve, and you might see some upslope on the left, under some buckeye trees. An assortment of chaparral plants, including poison oak, monkeyflower, coffeeberry, creambush,toyon, silktassel, sagebrush, hollyleaf cherry, and cercocarpus soak up the sun along the trail. Coast live oak, buckeye, and California bay offer some shade in sections. At 0.39 mile, there's a viewpoint on the right side of the trail, a mere sample of what's to come. Oak woodland on the lower reaches of Black Mountain Trail You may notice buckwheat blooming, and snowberry fruiting, along the trail in summer. The grade is moderately steep as Rhus Ridge Trail zigzags uphill. At 0.50 mile a path breaks off to the left. Continue straight on Rhus Ridge Trail. The longest steep section follows, and at 0.90 mile, the trail crests, then ends at a signed multiple junction. Turn right onto Black Mountain Trail.
      A grassy meadow slopes downhill on the left, and beyond the forested slopes of Black Mountain loom. You may be able to make out a string of high-tension power lines -- this is where you're headed on the way to the top. The medium-width trail, closed to cyclists, winds through oak woodlands at a level pace, then emerges in chaparral. Skirting the far reaches of a canyon that stretches through the eastern part of the park, Black Mountain Trail remains nearly flat. Black Mountain TrailAt 1.57 miles, a path to Hidden Villa departs on the right, from a signed junction. Continue straight on Black Mountain Trail.
     The trail, mostly shaded by coast live oaks, begins to climb at a moderately easy grade. At 1.78 miles, a second signed trail heads into Hidden Villa on the right. Continue straight on Black Mountain Trail.
     The trail spends a bit longer in the shade, then steps out into a plant community of chamise, silktassel, toyon, poison oak, coffeeberry, and cercocarpus. Small pockets of California bay, nestled in the mountain's creases, provide welcome shade on warm days. A series of switchbacks help the ascent stay gradual. I always expect to see animals along the trail, since coyote, bobcat, and fox scat is so common, but I've never seen anything more exotic than deer. You might notice a few manzanita shrubs and some madrone. A steep section of Black Mountain TrailFollowing one last, nearly level foray through coast live oak woods, the trail steps out under a high-tension power line, at 3.24 miles. Although broadened to fire road width, the trail is still closed to cyclists. From this point it's about 1000 feet (the bulk of it achieved in a little over 1 mile) to the summit. At first Black Mountain Trail runs along the power lines, through a combination of buckeye, coast live oak, poison oak, buckbrush, coyote brush, yerba santa, pitcher sage, and coffeeberry, but the trail soon curves left and heads uphill, while the power lines continue across the upper reaches of Hidden Villa. At 3.44 miles generic trail signs point you straight ahead, while a barely-there path breaks off to the right. Continue straight on Black Mountain Trail.
      The grade picks up significantly, and the trail leaves most tree cover behind. Occasionally a coast live oak shades the route, but for the most part, yerba santa, pitcher sage, scrub oak, hollyleaf cherry, manzanita, buckbrush, silktassel, and chamise line the trail. View west from the top of Black MountainIn winter look for pink flowers on chaparral currant shrubs. Ugly Kaiser Quarry is visible to the south. Although the route is fairly straight, some curves in the trail allow for a few surprises. One is a brief downhill stretch -- my heart drops with the grade each time I round that bend, for at this point in the ascent, every foot gained in elevation is an achievement, and it is no fun to go down in order to go up. There are more steep sections, some of them quite rocky. Views back to the east are a fine excuse when you need to stop and catch your breath. Finally, at 4.36 miles, you'll reach a gate. Continue past the step-over on Black Mountain trail to a signed junction at 4.42 miles, then turn right, "toward Monte Bello Road."
     Chaparral partly screens views to a hilltop collection of antennae, on the right. At 4.51 miles, the trail ends at a signed junction with Monte Bello Road, and marks the border with Monte Bello Open Space Preserve. Turn left.View east returning downhill
     After a brief gentle climb through grassland, you'll reach the top of Black Mountain, with an elevation just over 2800 feet. Look to the right for an unsigned path into some rock formations. Turn right, and at 4.58 you'll reach the turn-around point for the hike. You may spend some minutes looking for the USGS elevation marker, plastered into a rock. The views are outstanding: to the west Skyline Ridge and Butano Ridge are visible, south the highest elevations of the Santa Cruz Mountains stand out, and a glimpse north reveals the descending hills of Monte Bello. After the climb, it's pleasant to stretch out, loosen your boots, eat lunch, and refuel with something cold. When you're ready, retrace your steps back to the trailhead.

Total distance: 9.49 miles
Last hiked: Monday, August 26, 2002