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Mount Umunhum

Mount Umunhum

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Mount Umunhum

Page Type: Mountain/Rock

Location: California, United States, North America

Lat/Lon: 37.16060°N / 121.8975°W

Object Title: Mount Umunhum

County: Santa Clara

Activities: Hiking

Season: Spring, Summer, Fall, Winter

Elevation: 3486 ft / 1063 m


Page By: McCannster

Created/Edited: Apr 26, 2005 / Mar 18, 2017

Object ID: 153994

Hits: 27929 

Page Score: 86.37%  - 22 Votes 

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Given the complicated situation surrounding Mount Umunhum, this site is
purely for the sole purpose of showing the public simply what this place is all about. I do not condone trespassing in any way, and do not give descriptive explanations on how to get to the summit of Mount Umunhum. I share my personal experiences on this peak so that the good people of the South Bay Area who look up to this mountain wondering about it may have a better understanding of the place. If you post here, please do so discretely.

Fair Warning-READ THIS!

This page contains information about hiking on private property and closed areas of land. Any entanglements you get into while hiking around Mt. Umunhum is your fault, not mine, so don't blame anything on me. I just inform. If you are cited or arrested, you must assume full responsibility. Trespassing on the former Almaden Air force Station grounds is punishable by a misdemeanor along with a $300 fine.


682nd radar squadron patch
AAFS Patch

Mt. Umunhum (which roughly translates to "Hummingbird" in Ohlone Indian, pronounced UHM-un-uhm) is a major landmark in the south Bay Area and a truly unique peak. A mere three feet higher than its neighbor, Mt. Thayer, most people recognize it from the huge "box-like structure" that stands on its summit. This structure is sometimes referred to as "The Monolith", or "The Cube", yet is more commonly known just as "The Box". This was an 80 foot tall AN/FPS-24 radar tower. Between 1957 and 1980, the infamous Almaden Air Force Station, which occupied the summit area, housed many radar and transmitting equipment as lookouts for enemy planes coming in from the Pacific. The "box" at one point had a large radar dish on it until the closure of the station. When the Air Force abandoned the station due to better radars being built elsewhere, they left behind asbestos and lead-contaminated buildings. Thus, the summit is strictly off-limits to the general public. In other words, if you are a law-abiding citizen, do not attempt to climb this mountain, for going there simply means trespassing. The summit sits in the Sierra Azul Open Space Preserve, however, almost all approaches to the top go through private property owned by very isolated folks who do not like company. Mt. Umunhum would be considered class S10 on the "Sneak Peak Climbing" scale.

The  box  and summit of Mt....
The summit as seen from McQueen Ridge. All buildings seen in this photo (besides The Box) have since been torn down.

Since the creation of this page, there have been many changes in the status of Mount Umunhum. The path toward clean-up and public access has been a rocky one, and as of the end of 2013, all station structures have been torn down (besides the Box), the Box has been stripped of its outside paint, and general environmental clean-up has occurred. The old roads have been stripped of their asphalt, and re-planting of native plant species are taking place. The tearing down of the Air Force Station has certainly changed the character of Mount Umunhum from what it once was. Mid Pen is aiming to open the peak up to visitors in "2017". Since the Open Space organization is not interested in preserving "Historical  Sites", all funds to preserve the Box must come from outside the organization. The Umunhum Conservancy is a non-profit dedicated to raising the funds to help keep the iconic building standing for future South Bay Residents to enjoy. 1.2 million dollars are needed to save the Box, and the Conservancy does accept donations here (and they're tax deductible!). Please see the links below for more information about the clean-up project.

May 2016 Update- The Box is Here to Stay!!! The Santa Clara County Board of Supervisors have voted unanimously to list the Box as a Historical Heritage site, effectively safe-guarding the structure from demolition. This will ensure that Mount Umunhum will continue to hold the same character and allure as it always has, maintaining a key feature of the mountain skyline of San Jose. The opening of the summit to the public is being planned for later 2016. SJ Mercury Article on the announcement. 

Fall 2016 Update- Summit opening pushed back. Mid Pen has yet again pushed back the potential opening date for the mountain peak (big surprise). The new estimate now has the summit opening for public use in Fall 2017. New regulations recently enacted (see below in Getting There) provides hope that this new date will actually be the one!

  • Mid Peninsula Open Space Page on the Sierra Azul. Also check out what is going on with Mt. Um's future on the Master Plan page.
  • A very detailed .PDF map of the Sierra Azul and Bear Creek Redwoods Open Space Preserves that shows land ownership, property lines, etc.

    Mount Umunhum
    Mt Umunhum in the 70s.

    Getting There

    A Mighty Peak
    Mt. Um from Mt. Um Road.

    While there are quite a few approaches to the summit that I could elaborate on, I'm just going to give directions that do not describe any trespassing, just to be courteous to the landowners.

    The most direct way to get to Mt. Umunhum and the closest you can get to the summit in a car is Mt. Umunhum Road. From Camden Ave. in San Jose, turn west onto Hicks Road. Go past Shannon Road and Guadalupe Reservoir. After some elevation gain, you'll come to a rest area at a 4-way intersection and Mt. Umunhum Road to the right. Take the right and travel to gate SA-08 about 1.6 miles up Mt. Umunhum Road. There used to be limited parking here, but recent improvements have granted a very nice and large parking lot, with vault toilets. You are legally allowed to use non-motorized uses of transportation up beyond the gate on Mt. Umunhum Road, for 1.3 miles, at which point the road enters private property. From here on out, you are on your own.

    New regulations on Mount Umunhum Road (Fall 2016) In order to expedite the opening process of the mountain, Mid Pen has enacted new regulations on access to Mt Umunhum Road. As of September 2016, the entirety of Mount Umunhum Road that would otherwise be open to vehicular travel will be closed. Mt Umunhum Road above gate SA-08 will remain closed to all uses until the opening of the mountain in summer 2017. This closure also applies to hikers, bikers, and equestrian travel. Nobody is allowed on Mt Umunhum Road! This closure also includes Barlow Road, which connects Mount Umunhum Rd with Woods Trail, just up the hill from gate SA-08. 
  • Red Tape

    It is illegal to climb this mountain.

    1.3 miles above gate SA-08, the Mount Umunhum Road enters private property. Several signs as well as a warning painted across the road marks the boundary. If you proceed past this point, you are liable to receive a citation should you be discovered.

    There are a few people who live around Mt. Umunhum, and they are the type of people who you would rather not meet. There is a small trailer park-type of encampment where some people reside. This is located just off of Mt. Umunhum Road right at the first "No Trespassing" signs. There are some residences located on the ridge that connects Mt. Umunhum and Loma Prieta. Remember, even though you are just a few miles away from a large metropolitan area, it is basically anarchy up there. There's no telling what can happen if you are found by a landowner. Your rights may or may not be applicable.

    No Trespassing Sign

    When To Climb

    Anytime. Summer temperatures can get into the 100's. Winter can bring snow, but no more than a few inches. The summit can get quite windy, and 50+ mph gusts aren't uncommon.

    Mt. Umunhum
    Mt. Umunhum looms over south San Jose at dusk.


    Camping isn't allowed in Sierra Azul Open Space Preserve. 

    Summit B&W

    What's Up With Them White Albinos? -Rumors and Stories

    There are many weird stories and rumors that pertain to Mt. Umunhum, mainly due to the fact that its off limits. Most of these rumors are of false nature, but some are partly true. This section to inform of what is true and what is not true. Feel free to add info if you have it.

    One rumor says that Almaden Air Force Station is still in operation. I don't know where this came from, but if you see the place today, it doesn't take a rocket scientist to know that the place is very much abandoned.

    There are also stories of marijuana plantations around Mt. Umunhum. This is true. In August of 2005, a raid was done on a marijuana farm on the north western slope of El Sombroso, not far from Mt. Umunhum, that left one grower dead. On July 24, 2006, there was another raid closer to Mt. Umunhum in the Herbert Creek drainage, south of Mt. Umunhum Road. On July 10, 2007, the DEA eradicated even more pot plants in that same creek drainage. This is something to take into consideration when hiking Mt. Umunhum. I have no doubt that more marijuana farms linger in the hillside somewhere, and the growers obviously don't want anybody in there. It's best sticking to main routes to keep from accidentally stepping onto one.

    Another rumor is that the people who live around Mt. Umunhum carry guns and will fire at you. This has never happened to me, but countless people all over the net claim that they have been threatened with firearms. I have found bullet shells on the road near the summit, so this is something to think about.

    This rumor is a pretty weird one, and I have my doubts about it: somewhere around Mt. Umunhum, there is a enclave of hostile albinos that will kidnap you if you venture into their territory. This sounds like the stuff of legend. A while ago, I crossed paths with a land owner at gate SA-08 (not on private property) who mentioned to me something about "white albinos". I was also talking to a ranger for the Mid-peninsula Open Space District, and he said that there were some hard-core naturalist type of people living on the slopes of Mt. Umunhum. I don't know if he was serious or not, but it is an interesting idea I guess. Nevertheless, as it turns out, the "White Albino" rumor has circulated all around the Santa Cruz Mountains for many years. There has also been numerous reports of albinos living in Alum Rock Rock Park in the East Foothills. So, chances of there being crazy, hostile, cannibalistic white albinos near Mt. Umunhum are low...but one can never be too careful. The talk of albinos certainly is the most mysterious thing that surrounds the mountain, as well as the area. People talk of an "albino farm", which I believe is the trailer park off of Mt. Umunhum Road just before the "line of death". Another possible location for this alleged albino farm could be in the small Swedish retreat of Sveadal, a bit southeast of Umunhum. No albinos live at either location, as far as I know. I have heard stories of people on Hicks Road who inform the teens looking for albinos that "there is only one albino who lives up here, and he wants to be left alone." So, the legend is still open for debate.

    External Links

  • Care for a bushwhack? - Dec 6, 2005
  • Mt. Umunhum page at Wikipedia.
  • Radomes: Good Photos 
  • Almaden Air Force Station 2006 Reunion Photos. 
  • Article from Los Gatos Weekly Times here.

    Box Photos

    The  box  at the summit of...

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