Hiking Black Mountain in Rancho San Antonio County Park

At 2,812 feet, Black Mountain looms large, way up, and behind, the smaller hills to the west of Highway 280 in Silicon Valley. On a clear day you can see the Pacific Ocean, as well as San Francisco, and the entire Silicon Valley at your feet. You can also gaze at some of the other peaks in the Six-Pack of Peaks Challenge, including Mount Diablo, Mount Umunhum, and Mission Peak.

It feels so far away, yet so close, to the busy valleys down below. Take the time to peruse the many ways to get to the top! Some are easier than others, and some can be a parking headache on pleasant weekends!

This guide describes the “trail less travelled”, from an unofficial, yet completely legal trailhead, used by those “in the know”! It’s 11.5 miles and 2,800 feet of climbing. Following that are a few more approaches, some easier, some harder, and one that requires an easy-to-get permit for “V.I.P. Parking”!

Getting to the Trailhead

Set your GPS to 28100 Laura Court, Los Altos Hills, and park in the residential area.

Notice the interesting lake nearby, and imagine what it looked like as a rock quarry, many years ago.

Hiking the Trail

Head uphill, past the gate. It’s quite steep for a bit, until the junction with the more popular Chamise Trail. Turn right onto the Chamise Trail.

After about a mile, the trail forks, then rejoins itself after ~0.2 miles. At that 4-way intersection, continue uphill, and to the west, on the Black Mountain Trail.

Over the next 3 miles, you’ll be climbing gradually towards the triple communication towers. Just when you think you’re getting close, there’s a 100 foot dip in the trail, followed by a steep final climb. You’re there!

The official summit is where the “moon rocks” are, one of which has the official USGS Benchmark.

Black Mountain Trail Map & Elevation Profile

Download file: Black_Mountain_from_the_quarry.gpx

Black Mountain Tips

• When you return, on the final stretch to your starting point. There’s a little sign that says “Private Property Ahead”. No worries! This trail is heavily used, and not blocked or discouraged in any way. It’s not on the official map, however. MidPen tries to reduce the impact on residential neighborhoods.
• It can get hot in the summer! Water, sunscreen, and good shoes are a must.
• Phone signals are available on the majority of the trails.

Alternate Routes

• The most popular approach is from Rancho San Antonio Preserve (22500 Cristo Rey Dr, Cupertino, CA). It’s about 12 miles and 3200 feet, round trip. Be aware that the parking lot fills-up quickly, particularly on pleasant weekend days. This is the main park entrance, on the eastern edge of the park map.
• Another approach, with a very limited parking lot, is from the Rhus Ridge Trail. The hike is about 9 miles, and 2500 feet. It’s at the top-left of the park map, and is accessed from Rhus Ridge Road, off of Moody Road.
• There are two easy approaches, via the neighboring Monte Bello Open Space Preserve. One is to drive up Page Mill Road, to the parking lots marked on the map, in the area of “#3”. Hike east on one of several trails, then north to Black Mountain.
• Last, but not least, is to get a permit (and gate code) to park on upper Montebello Road, from the Midpeninsula Open Space folks (“Waterwheel Parking” permit application).  The park map shows both the parking lot, and Black Mountain, on the right side.

The Six-Pack of Peaks Challenge

This hike is part of the Bay Area Six-Pack of Peaks Challenge. This self-paced hiking challenge includes six hikes in San Francisco Bay Area. They are a great way to explore the area, train for bigger adventures, and you’ll be doing good, with a portion of the net proceeds going to support Big City Mountaineers.

The annual challenge runs between January 1st and December 31st.