Mount Umunhum in Silicon Valley offers stunning vistas

California Journal

If you don’t equate California’s Silicon Valley with nature, then you’ll be in for quite a surprise at Mount Umunhum, one of the San Francisco Bay Area’s newest open spaces.

The 3,486-foot summit provides stunning panoramic views (see my photo above) of San Jose, Santa Clara Valley and the Bay Area’s three other highest peaks — Mount Diablo and Mount Tamalpais to the North and Mount Hamilton (the tallest) in the South Bay. It was a clear day, so I also could see San Pablo Bay to the North and the Pacific Ocean to the West.

Map of Mount Umunhum in San Jose
Mount Umunhum is in Santa Clara County, just south of San Jose. (Google Maps)

The Mount Umunhum (the ‘h’ is silent) summit and trails just opened to the public six months ago, but they’re already popular with Sunday drivers, hikers and bicyclists. Mountain bikers are allowed on most of the trails and you’ll see road bikers on the steep and winding, 12-mile paved road to the summit.

I didn’t know anything about Mount Umunhum, but learned that it’s steeped in history.

Originally, the Ohlone Indian tribe inhabited the area.  The name “umunhum” comes from the Ohlone word for hummingbird. At the summit, a Ceremonial Circle honors the site’s American Indian heritage.

Mount Umunhum also was part of California’s first legal mining claim — the nearby New Almaden Quicksilver mine.

From 1957 to 1980, the summit was home to the Almaden Air Force Station. The early warning radar station was one of 23 in California and hundreds across the nation during the Cold War era. The radar tower still stands at the summit, but it’s closed.

Mount Umunhum radar tower
The old Almaden Air Force Station radar tower at the summit is closed. (Sheryl Jean)

You can download an audio tour app to your smartphone to learn about the site’s history.

The Midpeninsula Regional Open Space District bought the 36-acre site in 1986 and received $3.2 million in federal funds to help clean it up. The Bay Area Ridge Trail Council and the California Coastal Conservancy also provided funds, and helped develop and restore trails.

Today, 3.7 miles of trails from the Bald mountain parking lot to the summit traverse stately, moss-covered Coast Live Oak trees (see photo below), Foothill Pine, Mountain Mahogany, Manzanita and Madrone. On a recent walk there, I could smell the spicy sent of California Bay trees.

Watch out for poison oak.

Moss-covered Coast Live Oak tree
Moss-covered Coast Live Oak trees dotting the 3.7 miles of trails at Mount Umunhum provide welcome color. (Sheryl Jean)