El Sereno Open Space Preserve is named for 2,500-foot Mount El Sereno, part of a prominent ridge in the Santa Cruz Mountains that is located south of the city of Saratoga and west of the town of Los Gatos. A distinctive scenic backdrop to these cities, the 1,614-acre preserve rises from the foothills up steep slopes to the ridgeline. It is primarily an exposed chaparral community with meadows at higher elevations and a few shaded areas near creeks. El Sereno’s seven miles of wide, gradual trails are open for hiking, biking and dog walking, as well as horseback riding on designated trails.
The multi-use Montevina Ridge and Aquinas Trails offer an approximately eight-mile out-and-back route along the ridge, giving visitors spectacular panoramic views of Sierra Azul and St. Joseph’s Hill Open Space Preserves, Lexington Reservoir and Silicon Valley. While exploring this preserve, visitors may enjoy the fragrant smells of the California bay laurel and a variety of shrubs common in the chaparral habitat, including chamise, coyote bush and yerba santa. Visitors may also catch a glimpse of the mule deer, coyote, gopher snakes and brush rabbits that make their homes in the San Tomas Aquino Creek, Los Gatos Creek and Upper Los Gatos Creek watersheds.
The Aquinas Trail provides a three-mile trek along the ridge that offers spectacular panoramic views of Lexington Reservoir, Sierra Azul and St. Joseph's Hill Open Space Preserves, and the South Bay.
This 1.2 mile trail begins with a gradual slope through open grassland, and then enters a lightly shaded forest. A six-car parking area is available near the trailhead; however, a permit (no fee) is required to park in this lot. For additional details or to obtain a parking permit, please see the Permit Information page.
Preserve Highlights & Features
Most of your walk or ride will be filled with terrific views of the valley, Lexington Reservoir and Sierra Azul and St. Joseph's Hill preserves.
Expanding Ridge Trail
In the fall of 2020 and summer of 2021, Midpen partnered with the Peninsula Open Space Trust to expand El Sereno Preserve, one of the oldest in the agency's management portfolio. Funded by a grant from the California Wildlife Conservation Board, the purchase of 182 acres from the San Jose Water Company provided an important link in the preserve’s main trail and formally connected the 3.7-mile Aquinas Trail across the preserve. This advanced one of the priority action projects of the voter-supported Measure AA general obligation bond: the development of regional trail connections through El Sereno Preserve, which is also an important component of Midpen’s ongoing Highway 17 Wildlife and Regional Trail Crossings project. In October 2021, the Midpen board dedicated 3.5 miles of trail in El Sereno Preserve as part of the Bay Area Ridge Trail.
Senator Beall Commemorative Bench
On December 8, 2020, Midpen recognized state Sen. Jim Beall with a commemorative bench to honor his long-time dedication to the health of the open space lands of the Santa Cruz Mountains. Located on the Aquinas Trail, the bench faces south to overlook the lands surrounding Lexington Reservoir, with a view of San Jose to the east.
The landscape of Mount El Sereno is ideal for dog access. Dense brush and steep slopes help keep dogs within the trail corridor, which minimizes ecological disturbance, and the abundant chaparral plant communities have low sensitivity to any disturbance that might occur. During Midpen’s 18-month public visioning process that began in 2012, many El Sereno Preserve neighbors highlighted expanding dog access at the preserve as a priority for their community. After the board of directors approved the project to be included on the Five-Year Measure AA Project Prioritization List in 2014, Midpen staff held a number of public meetings and conducted a successful environmental review. The board opened the preserve to on-leash dog access in 2017.
Stories from the Preserves
Here are some of the plants and animals that other visitors have observed at this preserve and recorded in iNaturalist. Protected species may be excluded and some species may not yet have been observed. Help improve iNaturalist by adding your observations to the Midpen Biodiversity Index project
Join our e-mail list to stay up-to-date on this preserve and other Midpen news!
Know Before You Go
Preserve regulations help provide a safe, enjoyable visit while protecting sensitive areas and wildlife.
- The Aquinas Trail is currently OPEN.
Montevina Roadside Parking (2 cars): Accessible from the end of Montevina Road, three miles west of Highway 17. Take the Bear Creek Road/Montevina Road exit off Highway 17 and follow Montevina Road until it ends. There is limited parking at the roadside turnout.
- Bicyclists: Bicycles are allowed on designated trails only (marked on map). Helmets are required. Observe the 15 mph trail speed limit (5 mph when passing). E-bikes are not allowed on most Midpen trails. Avoid startling hikers and equestrians by announcing your presence when approaching from behind. For more information visit the Bicycle Access page.
- Dogs: Dogs are allowed only on designated trails in this preserve (marked on map) and must be controlled on a 6-foot or less leash. Self-retracting leashes are allowed with a maximum extended length of 25 feet. Extended leashes must be locked at 6’ when in the presence of other visitors. Visitors may have no more than three dogs per person. Bag dog waste and take it with you. Midpen accommodates service dogs in preserves wherever we allow public access. For more information visit the Dog Access page.
- Equestrians: Horses are allowed on designated trails (marked on map). Helmets are recommended for all equestrians. For more information visit the Equestrian Access page.
- Fires are prohibited in preserves.
- Plants & Wildlife: Please leave undisturbed. If you encounter wildlife during a visit, do not approach, startle or feed it. Although wild animals are generally fearful of humans and will run away, some wildlife can be dangerous.
- Smoking is prohibited in preserves.
- Water Areas: Swimming, wading or engaging in any water-contact activity is prohibited.
- Weapons are prohibited in preserves.
- Drones and Model Aircraft: Drones, model airplanes and model rockets are NOT allowed.
A permit is required to park in the Overlook Permit Parking Area.
- Permit applications should be submitted at least two business days in advance of the permit date requested. Applications submitted less than two business days in advance may be given consideration but cannot be guaranteed to be processed in time for the requested permit date.
- The permit is valid for a specific date.
- Permits will be issued on a first come, first served basis, with a maximum of six permits issued per day and 30 permits issued per month.
A general access permit is required for any activity or event that:
- may be attended by twenty (20) or more people; OR
- would restrict the use of any part of Midpen lands by members of the public; OR
- requests or requires a fee be paid or a donation made for participation. This includes events where the fee is in the form of a mandatory purchase, such as a t-shirt.
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.
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.
When biking, obey speed limit and ride in control. Avoid startling hikers and equestrians by announcing your presence when approaching from behind.
When visiting with dogs, follow dog access guidelines.
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.
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.
Activities & Events
El Sereno Preserve was acquired in 1975 and gave Midpen an early opportunity to protect land in the Los Gatos/Monte Sereno area.
El Sereno Preserve
Brochures and Resources
Some additional resources to help you enjoy the preserves!