A Sacred Site and a Cold War Relic

October 2018 Hiking


The tale

From as far away as my day job in Santa Clara, I can see a distinctive mark on the southern horizon: a strange block atop a mountain.

The block is an abandoned radar station atop Mt. Umunhum in the Sierra Azul Open Space Preserve. This giant structure was part of a west-coast network meant to detect Soviet bombers approaching from the Pacific in the 1980s.

There was no doubt. It must be explored.

The tower as seen from downtown San Jose.
The tower is visible from downtown San Jose.

But there was a problem. In 2017, lead-based paint from the radar building was found peeling from its concrete walls. Midpen closed the surrounding area “out of an abundance of caution for the safety of the public.” I also read warnings about ticks, mountain lions, rattlesnakes, and poison oak. Fun times.

So, how close could I get without suffering a slow (or exciting) death?

A scenic stroll to Bald Mountain

I awoke on Saturday in late October to a dull, ruddy sunrise filtered by intermittent mist. I wondered if packing only one heavy shirt was enough.

The preserve was only 45 minutes south of San Jose by car. Following the obligatory switchback road, I reached the Bald Mountain parking lot, near the trailhead, around 8:15am. The lot had about 30 or 40 spots — less half of which were taken.

I was overdressed. The meager sun made for shorts-and-t-shirt weather. Cooler weather was in the forecast … for next Tuesday. I predicted this day would be hot.

My final destination was to the west, but decided to explore Bald Mountain first. This round overlook was three-quarters of a mile to the east, and I reached the trail’s end after a measly 15 minutes. The site was low on trees and high on scenery.

Sunrise view from Bald Mountain. 
Half an hour or so after sunrise, looking east from Bald Moutain in Sierra Azul OSP.

Another fifteen minutes later I was back at my car. The lot was almost full. And I was ready for the main event.

Climbing Mount Umunhum

Learning to pronounce “Umunhum” was tricky until a ranger described it to me as “M&M” but with “um”s. I also got an early muppets skit stuck in my head. But the mountain has more significance than that.

Umunhum is an Ohlone word that means “resting place of the hummingbird.” Its rich history goes back centuries. Before the area was mined for cinnabar and mercury, it was settled by the Olhone and Amah Mutson tribes. Geologically, the mountain was part of the region’s numerous millions-of-years-old fault lines.

But in late October 2018, I just wanted to reach the summit — 1150 feet higher than the trailhead. With trekking poles in hand and two liters of water on my back, I felt ready to face a hot, uphill challenge.

The trek started well. Not only was the trail protected by dense oak coverage, but it also kept to the north side of the hills. At this time of year, the sun stayed low enough to keep it behind most summits in the morning. Ample shade was a welcome surprise.

Protective containers for oak saplings. 
Protective containers for oak saplings.

Along the way, I passed plastic cylinders stuck in the ground. Later, a friendly ranger told me that they were protective coverings for oak saplings … which didn’t always work. Having peeked into two, I agreed. But the fact that someone had taken time to install them spoke of how well the preserve was kept.

After two miles, the steady climb hadn’t presented much of a challenge. The trail, which Midpen restored in 2014–2016, was in great shape: wide enough for two or three people to walk abreast, and free of debris and fallen limbs.

Fall colors: poison oak 
Poison oak turns red in the fall.

But poison oak, one of the area’s most common hazards, was prevalent. The toxic plant also provided the most fall colors I saw on this autumn day.

And still the trail was gentle. Markers placed every half mile indicated I was making good time, even with frequent stops to shoot photos. I was doing well. Suspiciously well. When would the trail get challenging?

Well … it didn’t.

View from the Guadalupe Creek overlook. 
View from the Guadalupe Creek overlook.

Circle and block

I reached the summit around 10:30am, not quite two hours after setting out from the Bald Mountain parking lot.

San Jose, as seen from the summit. 
San Jose as seen from the top of Mt. Umunhum.

I passed another small parking lot adjacent to an empty emergency helipad and at the base of a 159-step stairway. Climbing those steps was the steepest part of the hike. Not bad at all.

There were no trees at the summit, and the sun was out in force. I paused to look north towards San Jose, which lay under a faint blue haze. Then I ventured to the circle.

Prayer circle on the summit. 
Built only a few years ago, the circle is where people pray to the four cardinal directions.

I read that the Amah Mutson use the site as a place of healing and prayer, though I wasn’t clear how often events occur. The rocky, well-kept circle looks large enough to hold plenty of people.

Radar tower at the summit. 
The abandoned radar tower was blocked off.

Finally, there it was. The spinning antenna no longer crowned the enormous block, but the building was imposing nonetheless. At 84 feet tall, I finally understood why it was visible from as far away as Santa Clara.

As promised, the monolithic structure itself was fenced off. But that didn’t matter. It was impressive even from 50 feet away.

Shelter at the summit of Mt. Umunhum. 
Cyclists and hikers alike take refuge inside the covered shelter.

I lingered in the shade of a new-looking shelter, shooting photos, eating a snack, and chatting with people. At least 20 folks ambled about while I was there. Almost half of them had cycled from the base. I also learned that it was a tricky drive for cars, full of switchbacks and blind corners, and one couple rambled on about their trip to Machu Picchu.

Back again

An hour later I left the radar behind to begin hiking back the way I’d come. Suddenly I realized that since I was retracing my steps, both the radar and my route were palindromes. I kept an eye out for a tacocat to tell my Mom about. (Most likely response: he did, eh?)

For next time

  • Bring plenty of water. There’s none at either end of the trail.
  • I didn’t find any trash cans at the summit. Be prepared to pack out any trash, like food wrappers, you bring.
  • Try starting at the top and heading down first for wider landscape views bathed in magic-hour lighting.
  • There is no shade at any of the parking lots I saw. Be prepared for your vehicle to act like an oven under the sun.

Update: three months later

In January 2019, I returned to the summit on a windy, rainy day. The view didn’t disappoint.