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Mount Umunhum Summit and Back



8.3 mile 13.3 kilometer out and back
92% Runnable


Ascent: 1,195' 364 m
Descent: -1,195' -364 m
High: 3,474' 1,059 m
Low: 2,317' 706 m


Avg Grade: 5% (3°)
Max Grade: 44% (24°)


No Dogs
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Trail shared by Shlomo Waser

Combine nature, amazing scenery, and interesting history while running to one of the highest peaks in the Santa Cruz Mts.

Shlomo Waser

Features Birding · Views · Wildlife


Explore one of the highest peaks in the Santa Cruz Mountains. This excellent trail has it all. Runners will enjoy nature with lots of different plants, amazing scenic views in all directions, and very interesting history.

Need to Know

About a third of the trail is exposed to the sun, so start early when the days are hot.
The Bald Mountain parking has limited parking, which is another reason to start early.
Download a free audio guide describing the natural environment, the scenery, and the rich history of the area on the Sierra Azul website.

Runner Notes

Good trail for runners.


This trail was opened to the public on September 18, 2017. The trail starts at the parking lot of Bald Mountain Trail.

It climbs steadily (1,200 ft) for 3.7 miles to the summit of Mount Umunhum, one of the highest peaks in the Santa Cruz Mountains. The trail is excellent and easy to follow, making its way up lots of switchbacks to ease the climb.

The trail goes through a variety of trees such as oak, madrone, manzanita etc. 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.

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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Jun 4, 2018
Ryan Rodrigues

Trail Ratings

  4.4 from 16 votes


  4.4 from 16 votes
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in California


167 Views Last Month
9,526 Since Sep 28, 2017



Up ahead is Mt. Umunhum summit
Nov 11, 2017 near Almaden…, CA
Mt. Umunhum, 3,488 ft., as seen from the north
Sep 1, 2017 near Lexingt…, CA
Native American Ceremonial Circle on top of Mount Umunhum. A sacred place for thousands of years to Native Americans.
Sep 30, 2017 near Lexingt…, CA
Plaque near the top.
Oct 27, 2018 near Lexingt…, CA
Very clean resting/picnic area near the top.
Oct 27, 2018 near Lexingt…, CA
Looking towards the valley from Guadalupe Creek Overlook, late one August afternoon.
Aug 10, 2019 near Almaden…, CA


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