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Mount Umunhum Loop

 4.0 (14)
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13.9 Miles 22.4 Kilometers



2,408' 734 m


-2,423' -739 m



Avg Grade (4°)


Max Grade (19°)

3,459' 1,054 m


1,301' 397 m


Shared By Shlomo Waser


All Clear 30 days ago
Some Mud, Icy History

Getting forecast...

Ride through forest to explore one of the highest peaks in the Santa Cruz Mountains.

Shlomo Waser

Dogs No Dogs

Features -none-


This ride takes you through the Sierra Azul forest to the summit of Mount Umunhum where the views are stunning. This summit is one of the highest peaks in the Santa Cruz Mountains and also has very interesting history.

Need to Know

Get more info and download a free audio guide describing the natural environment, the scenery, and the rich history of the area:…


This loop ride starts at the east entrance of Sierra Azul Open Space Preserve (at the intersection of Hicks Road and Mount Umunhum Road).

Ride up Mount Umunhum Road (10-12% slope), and after 1.7 miles, there is a large display sign on the right side of the road. This is the trailhead for the singletrack Mount Umunhum Trail. (This trail was opened to the public on September 18, 2017.)

Ride through the forest for 3.5 miles with lots of hairpin switchbacks. The average slope is about 6%. The last 0.2 miles is open only to hikers. To reach the summit, ride for 0.2 miles on the paved road.

The views from the summit are great: Silicon Valley lies below you, and (on a clear day) one can see all the way to San Francisco, Monterey Bay, and the Pacific Ocean. There are great views of all the mountains in the area, including Mount Hamilton and Mount Diablo. There are a few interpretive signs along the trail and many more on the summit area.

After the summit visit, ride down the Mount Umunhum Trail for about 3.2 miles, where the doubletrack Barlow Road starts. Take this connector trail for 1.5 miles to Woods Trail. The last section of the Barlow is quite steep (more than 20%). Turn right on the doubletrack Woods Trail and ride it for 2.3 miles back to the starting point. This section of the Woods Trail is quite moderate with lots of shade.

History & Background

The summit of Mount Umunhum has an eight-story concrete tower that is visible from many places in the South Bay Area. That tower was once a base holding a radar dish operated by the US Air Force from 1957-1980. After the base closed, the land was bought by the Mid Peninsula Open Space District (Mid-Pen) to be used as an open space for the public. However, due to hazardous materials and other safety issues, it was not open to the public until September 18, 2017.

For over 30 years, Mid-Pen worked on returning the area to mostly its original natural environment. However, they kept the iconic 86-foot tower.

The mountain's name means Hummingbird in the Ohlone language.


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Your Check-Ins


Mar 13, 2019
Leo Ang
Dec 18, 2018
Adam Hemmingson
Oct 14, 2018
Megan Dillon
Sep 9, 2018
Sergiy Cherepov
watch for a loose gravel 13.9mi
Aug 17, 2018
Steve Dorsey
New access makes this a popular trail for hikers. Be careful. Very pretty, shaded, and a bit flowy. Fun climb and descent. Great shape - manicured.
Aug 5, 2018
Morten Nissov
Trail in good condition. A little too much road and the main trail is not very exciting. The views however are grand. 13.9mi
Jul 13, 2018
Ɓukasz Karolewski
Jun 10, 2018
Derek Walters

Trail Ratings

  4.0 from 14 votes


  4.0 from 14 votes
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in California


224 Views Last Month
6,613 Since Oct 4, 2017
Intermediate Intermediate

I think the Blue/Black some people rated is due to the steepness (>10%) in some parts of the trail. Nothing technical in the singletrack, but some switchbacks are very tight. Barlow and Woods trail does have some very loose gravel sections - so caution there when carrying speed. But otherwise an pretty easy going trail if you have the fitness level to climb the grade. Feb 21, 2018

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