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California Trails

Mount Umunhum to Finally Open to the Public

The Bay Area's third-highest peak, Umunhum, has turned from Air Force surveillance site into the Sierra Azul Open Space.

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Sacred to the Ohlone people before becoming a place to watch for Russian war planes over the Pacific, Mount Umunhum will now be known as the Sierra Azul Open Space. The 3,486-foot peak has stunning vistas of the Santa Cruz Mountains—and while the radar station (often called “the box”) isn’t open to the public, there’s a visitor center and 3.5 miles of new trails.