Sierra Azul Preserve

Overview

Hours

Open a half-hour before sunrise until a half-hour after sunset, except the Mount Umunhum area, which is open from 7 a.m. until a half-hour after sunset. The Mount Umunhum area entrance gate closes at sunset in order to ensure visitors have time to safely exit the preserve before closing time.

The largest of the open space lands that Midpen manages, Sierra Azul Preserve protects more than 19,000 acres of wilderness in the Santa Cruz Mountains. Overlooking the Lexington Reservoir, Los Gatos and southern neighborhoods of San Jose, the preserve encompasses much of the Sierra Azul range and its foothills - topped by the 3,486-foot peak of Mount Umunhum. With 26 miles of multiuse trails for hiking, dog walking, biking and horseback riding, the varied landscape offers visitors views of serpentine grasslands, rocky and steep chaparral, dense stands of bay trees, shaded oak woodland forests, deep ravines and riparian corridors that surround the seasonal or year-round water flow. Prime mountain lion habitat, Sierra Azul Preserve also provides homes for deer, bobcats, coyotes and many other species of animals.

This preserve has the beauty and ruggedness of an unspoiled wilderness, but has been inhabited by people for a millennia. Native Americans have celebrated their traditions and histories at Mount Umunhum, which figures prominently in the Amah Mutsun people's creation story. German and Austrian refugees of the Franco-Prussian War settled in the area in 1870 to be near the New Almaden Quicksilver mining operations, developing the land for orchards and vineyards. From 1957 to 1980, the Mount Umunhum summit was the site of the Almaden Air Force Station, which served as part of a network of radar stations. The square concrete structure that is still visible was once the base for a large Cold War-era radar sail.

Due to its size, Sierra Azul Preserve is divided into four areas. Two are open to the public: Kennedy-Limekiln and Mount Umunhum, which opened in 2017 after a nearly decade-long effort to remove many of the abandoned military buildings, clean up the site's hazardous materials and restore the summit. Cathedral Oaks and Rancho de Guadalupe Areas are closed, but opening them to public access are priority projects of the Measure AA general obligation bond.

Hiking: All Trails

Bicycling: Designated Trails

Equestrian: Designated Trails

Dogs on Leash: Designated Trails

Easy Access: Designated Trails

Restrooms: Available

Kid Friendly

Download Map Trail Closures

Mt. Umunhum (Lubor Ptacek)

Stories of Mount Umunhum

The Stories of Mount Umunhum audio tour app allows you experience a virtual guided tour around the summit of Mt. Umunhum at your own pace. Learn how Mount Umunhum got its name and hear Air Force veterans, Native Americans and others tell their personal stories about life on the mountain.

The Stories of Mount Umunhum app is available for free on the App Store and Google Play. We recommend downloading the audio tour app before your visit, because cell service and wireless connectivity can be limited in the area.

Preserve Highlights & Features

East summit, Mount Umunhum, Sierra Azul Preserve (Deborah Hirst)

Mount Umunhum

Mount Umunhum is one of the highest peaks in the Santa Cruz mountain range at 3,486 feet. You can hike to (or from) the summit on the multiuse Mount Umunhum Trail, which passes through mixed chaparral scrub, knobcone pine forest, coastal woodlands and steep, exposed terrain with cliffs and rocky outcrops. The summit's rocky, nutrient-poor serpentine soils are home to numerous endemic plant species, including rare flowering plants that reveal themselves each spring. From its summit, visitors can experience 360-degree views from the Pacific to the Sierra Nevada and learn about the mountain's long history with Native Americans, gold rush-era mining and the Cold War. The summit is accessible to visitors of all abilities.

Download Mt. Umunhum trails map

Stories from the Preserves

Learning From Nature and Building Resilience

The Midpen board of directors received an update from staff on progress toward our goal of reducing…

Midpen’s Highway 17 Wildlife and Trail Crossing Project Moves Forward

Midpen is entering a critical stage in its Highway 17 Wildlife and Trail Crossing Project. This…

Purple Martin Nesting Enhancement

Midpen has undertaken significant efforts to help stabilize the local population of purple martins…

Wildland Fire Takes a Village

Midpen forms part of the Los Gatos Creek Watershed Collaborative, a joint group taking a holistic…

Midpen Purchases 100-Acre Inholding in Sierra Azul Open Space Preserve

Midpen purchased 102 acres from San Jose Water Company that will extend Sierra Azul Open Space…

Newt Passage Project Proceeds

Midpen has been working with Santa Clara County, which owns Alma Bridge Road that parallels…

Know Before You Go

Preserve regulations help provide a safe, enjoyable visit while protecting sensitive areas and wildlife.

YIELD. Bicycles yield to hikers and equestrians. HIkers yield to equestrians.

Share the Trail

Use designated trails to avoid damage to natural resources and prevent injury.
Avoid blocking the trail. Step aside to allow others to pass .
Whether you’re walking or biking, always yield to equestrians.
Leave no trace. Pack out what you pack in. Most preserves do not have trash cans. Littering is prohibited.
Abuses of trail etiquette should be brought to the attention of a ranger or call the Midpen main office at 650-691-1200.

KENNEDY-LIMEKILN AREA

Kennedy Roadside Parking (3 spaces): Located in Los Gatos on Kennedy Road at gate #SA01.

MOUNT UMUNHUM AREA

Mount Umunhum Summit Parking Area (54 spaces + 3 ADA): For summit paths and Mt. Umunhum Trail trailhead. Located at the top of Mt. Umunhum road, approximately 5.3 miles past the intersection with Hicks Road. The parking area will be on the left and stairs will lead visitors to the Summit. A limited number of accessible parking spaces are located 0.2 miles further up Mt. Umunhum Road within the passenger dropoff/turnaround area.
Mount Umunhum Summit Accessible Parking Area (3 ADA)

EAST AREA

Jacques Ridge Parking Area (11 spaces + 1 ADA): For Woods Trail trailhead. Located near the intersection of Hicks Road and Mt. Umunhum Road. Parking area is on the right.
Bald Mountain Parking Area (23 spaces + 1 ADA): For Mt. Umunhum Trail and Bald Mountain Trail trailheads. Located on Mt. Umunhum Road, approximately 1.7 miles past the intersection of Hicks Road. Parking area is on the left.
Bald Mountain Roadside Parking (4 spaces)

WEST AREA

Miller Point Parking Area (33 spaces + 2 ADA): Located in Lexington Reservoir County Park land, south of the County's Banjo Point Parking Area and gate SA21 which leads into Priest Rock Trail.

EQUESTRIAN PARKING

Jacques Ridge Equestrian Parking Area (7 equestrian spaces): Located on Almaden Quicksilver County Park lands, at the edge of Sierra Azul preserve.

Drones and Model Aircraft: Drones, model airplanes and model rockets are NOT allowed.

Dogs: Dogs are NOT allowed on Mount Umunhum (trail, summit, parking lots, or Mt. Umunhum road, this includes dogs in cars). For information on dog-friendly preserves visit the Dog Access page. In accordance with the Americans with Disabilities Act, Midpen accommodates service dogs in Preserves wherever we allow public access.
Bicyclists: Bikes are allowed on designated trails in this Preserve. Helmets are required for all riders at all times. Please observe the 15-mph trail speed limit (5-mph when passing or approaching blind turns). For more information visit the Bicycle Access page.
Equestrians: Horses are allowed on designated trails in this Preserve. Helmets are recommended for all equestrians. For more information visit the Equestrian Access page. Non-potable water for horses is available at the summit.
Fires: Fires are prohibited on preserves.
Smoking: Smoking is prohibited on preserves.
Weapons: Weapons of any kind are prohibited on preserves.
Plants and Animals: Please leave plants and animals undisturbed. This not only preserves the natural environment, but is also a safety precaution.
Water Areas: Swimming wading, or engaging in any water-contact activity in any water areas of the District is prohibited.

Download District Regulations and Ordinances

Midpen trails and facilities are generally very safe. However, you are entering an environment where there are some naturally occurring hazards. Reasonable caution and common sense should be utilized when venturing into any outdoor environment.

Do not leave valuables in your vehicle! Lock your vehicle and store valuables out of sight or take them with you on the trail.
Travel in groups of two or more. Two of more people can assist each other in the event of an accident or emergency.
Dress for the environment. Temperature changes can be occur and you should dress in layers appropriate for the location, time of year and planned activities.
Carry water with you. Drinking water is not available at most Midpen preserves so you should bring your own. Two quarts per person per two hour hike is recommended.
Apply sunscreen and drink plenty of water prior to and during your outdoor activities.
Be aware that cell service is very sporadic on the preserves.

Be Prepared and Aware

Plan ahead before you leave. Check regulations and weather, download a map, pack water and first aid.
Know your limits and take safety precautions.
Rattlesnakes are native to this area and are especially active in warm weather.
Poison oak grows on most preserves: Learn to identify and avoid it in all seasons.
Ticks are present in this area and may carry diseases.
Mountain lions are a natural part of this region’s environment and are occasionally seen.

In Case of Emergency

If you experience an emergency (fire, accident or other immediate threat to life or property), call 911. For nonemergencies, call 650-691-1200.

History

In addition to its unique habitats and geological features, Mount Umunhum has an important role in the region’s local and cultural history. For millennia, Native Americans have celebrated their traditions and histories at Mount Umunhum. The word “Umunhum” means “resting place of the hummingbird”, and signifies the delivery of fire to the Amah Mutsun people.

From 1957 to 1980, the summit was the site of the former Almaden Air Force Station where it served as part of a network of radar stations. The square concrete structure at the top of Mount Umunhum was once the base for a large Cold War-era radar sail. The summit has been closed since 1980 when the base was decommissioned. The base was acquired by the District and added to the Sierra Azul Open Space Preserve in 1986. In 2009, Midpen received federal funding, which enabled Midpen to clean up the site. Over 3,000 cubic yards of hazardous materials, including lead paint, asbestos, fuel storage containers and PCB transformers were removed along with13,680 tons of concrete, asphalt, wood and other materials, 97% of which were recycled or reused.