Mount Umunhum Trail

The primary access point for the trail is the Bald Mountain parking area. From there, you can begin your hike towards the summit.

The trail is generally dog-friendly, but always check the latest regulations for the Sierra Azul Open Space Preserve regarding leash requirements and specific areas where dogs might not be permitted. It's best to keep your dog on a leash for their safety and to protect wildlife.

Spring is particularly beautiful, with wildflowers lining the path. However, the trail offers ample shade for much of the upper three miles, making it enjoyable even on warmer days. Clear days provide the most expansive views, so checking the weather forecast is recommended.

No permits or entrance fees are typically required to hike the trail within the Sierra Azul Open Space Preserve. However, it's always wise to check the official Midpeninsula Regional Open Space District website for any updated regulations or temporary closures before your visit.

The hike to the summit from the Bald Mountain parking area is approximately 3.7 to 4 miles one-way, making it about 7.4 to 8 miles round-trip. The average duration for this hike is around 2 hours, though this can vary based on your pace and how long you spend enjoying the views at the summit.

While it presents a moderate challenge with an elevation gain of around 1,141 to 1,200 feet, the trail features a well-maintained path with a gradual, steady ascent and numerous switchbacks to ease the climb. This design makes it enjoyable for many visitors, including those with some hiking experience. The final 0.2 miles to the summit involve steps across a steep rock face and are for hiking only.

You'll be treated to spectacular and expansive views of Silicon Valley, the Santa Cruz Mountains, and the Pacific Ocean. The summit features the iconic cube-shaped radar tower, a relic of the Cold War-era Almaden Air Force Station, and a Ceremonial Circle honoring Native American heritage. The trail itself leads to Mount Umunhum, one of the highest peaks in the Santa Cruz Mountains, offering 360-degree panoramic views.

The path winds through varied habitats, starting with chaparral scrub and then entering knobcone pine woodlands and coastal woodlands dominated by oak, foothill pine, California bay, and Pacific madrone, providing ample shade. Near the top, the terrain opens up to cliffs and rocky outcrops, including serpentine boulders. The trail is multi-use for most of its length, accommodating hikers, bicyclists, and equestrians.

Yes, the route also passes through significant sections of the Bay Area Ridge Trail - 03 - South Bay, and naturally, the Mount Umunhum Trail itself.

The diverse landscapes, including oak woodlands, chaparral, and pine forests, provide opportunities to spot wildlife such as deer and hawks. In spring, colorful wildflowers line the path. The trail also passes through unique ecological zones with serpentine soils that host rare and endemic plant species.

After extensive restoration efforts, including the cleanup of hazardous materials from the former Air Force station, the trail and summit were reopened to the public in September 2017. This made the historically and ecologically significant area accessible for recreation, with the trail designed with a gentle grade for broad enjoyment.