Thornewood Open Space Preserve

Thornewood is the kind of place you can drive past for years without knowing it is there. A brick gate on La Honda Road leads up a narrow lane into the woods above Woodside. At the end is a small Midpen preserve of 167 acres with an easy trail to a quiet lake, a few stone ruins from a grand summer estate and a 1920s house that is still standing.

The Midpeninsula Regional Open Space District, known as Midpen, pitches it as a quick morning or afternoon getaway with easy hikes or horseback rides. It also allows leashed dogs, which makes it one of the few preserves near Palo Alto where a dog and a toddler can share a gentle forest walk. This guide covers the drive, the trails, the estate history and the rules.

Getting there and parking

From Palo Alto, take Interstate 280 north to Woodside Road (Highway 84) and head west through Woodside village. At the junction with Portola Road, stay on Highway 84, which becomes La Honda Road and starts to climb. Midpen puts the entrance 1.6 miles past that intersection, on the south (left) side of the road. Allow about 25 to 30 minutes from downtown Palo Alto.

The gate is easy to miss on the curves. Once through it, a narrow driveway winds 0.3 miles through the woods to the parking area on the west side of the drive. Drive slowly, since you may meet cars coming down.

• Parking: 5 spaces plus 1 accessible space. That is all. On a sunny weekend, arrive early or have a backup plan.
• Horses: there is no equestrian parking.
• Hours: a half hour before sunrise to a half hour after sunset.
• Fee: none.
• Restrooms and water: none. Bring water.

Do not park on Highway 84 if the lot is full. The shoulders are narrow and the road is busy with cyclists and motorcycles heading to Skyline.

The trails to Schilling Lake

Midpen describes two main trails. Both are short and mostly shaded.

For a first visit, walk the Schilling Trail from the entrance, detour onto the Rock of Ages Trail for the ruins and continue to the lake. The round trip is about 1.5 miles plus the spur. Take the Bridle Trail on the way back if you want a different forest and a slightly longer loop.

Midpen has one standing advisory: crossing Dennis Martin Creek on the Bridle Trail is not advised during high water. After a big winter storm, stick to the Schilling Trail.

The Schilling estate ruins

August Schilling cofounded the Schilling Spice Company in San Francisco in 1881. According to Midpen, he bought land from the Thornes and built a 150-acre estate here with a mansion he called Portola Hall. After Schilling died in 1934, the mansion was demolished in 1952 because it was a fire hazard. In 1978 Midpen bought parcels that had been part of his estate.

The four panels along the Rock of Ages Trail point out what is left:

• The Redwood Temple. Built around 1920, it was made of redwood logs and is estimated to have stood 50 feet tall and 40 feet wide. A central fountain flowed through grooves in the concrete base into an artificial stream that ran down to the lake. Only the foundation and fountain basin remain.
• The Rock of Ages. A jasper boulder inscribed "Memento Mori," Latin for "remember you must die." Midpen says the rock likely came from Fremont, near salt ponds once run by Schilling and the Leslie Salt Company.
• The pergola. Remnants of a redwood pergola that Midpen calls the high point of the estate's artificial features. The trail itself was once a road for cars and carriages.

Midpen notes that wealthy San Franciscans often kept summer estates with mansions and elaborate gardens in these mountains. Filoli, a few miles north, is the best preserved example and is open to visitors.

The Thornewood house

The preserve takes its name from Edna and Julian Thorne. Julian Thorne, a San Franciscan, bought the property in 1908. In the 1920s the architect Gardner Dailey designed their summer home. Midpen notes that Dailey also designed the farm buildings at Filoli, an addition to the de Young Museum and the American Embassy in Manila. Thorne kept his estate and sold the rest of his land, which reached to Skyline Boulevard, to Schilling.

The house sits in 3.5 acres of landscaping with a long view over the valley. Midpen calls it an example of 1920s estate life. The 87-acre Thorne estate was willed to the Sierra Club Foundation and later given to the district. Today the house and a 10-acre private leasehold are being restored and are closed to the public. The other 77 acres, including the walk to the lake, are open all year.

Schilling Lake is becoming a meadow

Schilling built the lake as part of his landscape. Midpen has decided to let it fill in on its own through ecological succession. Decaying plant material and sediment are slowly turning the pond into a wet meadow. Shrubs and trees will follow. Eventually the area will look like the forest around it. The animals that use it will change along the way.

It has been a good place to watch migrating waterfowl, so bring binoculars in winter. Just expect reeds and marsh rather than a postcard lake. Midpen calls it sensitive wildlife habitat and asks dog owners to keep their dogs leashed and at their side here.

Dogs, horses and other rules

• Dogs: allowed on a leash of 6 feet or less. Retractable leashes may extend to 25 feet but must be locked at 6 feet near other visitors. No more than three dogs per person. Midpen's preserve icons and its dog page list all trails as open to dogs, while the regulations text says designated trails marked on the map; follow the signs at the trailhead.
• Dog waste: Midpen is testing a dog waste bin in the Thornewood parking area. Otherwise, carry the bag out.
• Horses: allowed on designated trails. Helmets are recommended. There is no trailer parking at the preserve, so plan how you will get a horse here before you go.
• Bikes: not allowed.
• Water: no swimming, wading or water contact in the lake or creek.
• Also prohibited: drones, fires, smoking and weapons.

Rules and closures can change. Check the Midpen preserve page before you go. For more places to hike with a dog, see our dog-friendly hikes guide.

Seasons and fire weather

The forest canopy keeps Thornewood cool on summer afternoons when the grassland preserves bake. Fall brings yellow bigleaf maple leaves along the Schilling Trail; our fall colors guide covers where else to look. Winter means mud, high water at the creek crossing and the best chance of ducks on the lake. Spring brings new green to the maples and ferns.

Fires are banned in Midpen preserves all year. Midpen does not post a seasonal closure for Thornewood, but any preserve can close during extreme fire weather or after storm damage. Midpen's calendar lists a guided walk called Coffee and Spice: A Natural and Cultural History on December 11, 2026 and February 17, 2027.

Safety

What pairs nearby

Thornewood is short, so it pairs well with a stop in Woodside or another trail.

• Woodside village: the historic Woodside Store and a few cafes on the way up.
• Wunderlich Park: a bigger county park off Woodside Road with longer redwood loops. Dogs are not allowed there.
• La Honda Creek Preserve: farther up Highway 84, with big ridge views.
• Pulgas Ridge: the off-leash option if your dog needs a real run.

Frequently asked questions