Pulgas Ridge Open Space Preserve

Ask a Peninsula dog owner where to go for a real off-leash walk on trails and most will say Pulgas Ridge. The Midpeninsula Regional Open Space District, known as Midpen, manages 366 acres here on the edge of San Carlos. It is the only one of its preserves with an area where dogs can run free. The rest of the preserve is a pleasant little network of about 6 miles of trail with cool canyons, oak and chaparral slopes and views toward the bay.

Our dog-friendly hikes guide gives Pulgas Ridge a paragraph. This page covers the rest: exactly how the off-leash zone works, the named trails and the loop most people walk, parking, the rules for everyone else and the tuberculosis hospital that once stood on the hill.

Getting there and parking

From Palo Alto, take Interstate 280 north to the Edgewood Road exit. Midpen's directions: drive 0.75 miles northeast on Edgewood Road toward Redwood City, turn left on Crestview Drive, then turn left again right away onto Edmonds Road. Follow Edmonds Road to the preserve entrance on the right. In light traffic the drive takes about 20 minutes from downtown Palo Alto.

The Pulgas Ridge Parking Area holds 23 cars plus 2 accessible spaces. It is the only lot. Midpen does not publish a fill time, but a small lot that serves the area's only off-leash trail zone gets busy on weekend mornings. If it is full, do not park on the residential streets in ways that block driveways. Come back later or try another preserve.

• Hours: a half hour before sunrise to a half hour after sunset.
• Fee: none. Midpen preserves charge no entry or parking fee.
• Restrooms: Midpen lists restrooms as available.
• Water: do not count on drinking water. Bring enough for you and the dog.
• Dog waste bins: Midpen is testing waste bins in the parking area as a pilot program. Otherwise, bag it and carry it out.

How the off-leash area works

The off-leash area covers 17.5 acres in the middle of the preserve. You reach it from the Cordilleras Trail, from the Polly Geraci and Hassler trails or from the Blue Oak Trail. Midpen's rules inside the zone are short:

1. Carry a leash for every dog, even while it runs.
2. Keep your dog under voice control at all times.
3. Leash up again as soon as you leave the zone.

The zone is signed at its entrances, but Midpen is clear that there is no fence around it. That matters. A dog that bolts after a deer or another dog can be on a leash-only trail in seconds. If your dog's recall is shaky, treat this as a long-leash walk and let it off only once you know the ground.

Outside the zone, Midpen's standard dog rules apply. Use a leash of 6 feet or less. Self-retracting leashes may extend to 25 feet. No more than three dogs per person are allowed. Midpen accommodates service dogs wherever the public may go. Palo Alto licensing rules are on our pets page and the city's own fenced runs are listed in our dog parks guide.

The trails

Midpen describes about 6 miles of trail. These are the named routes on its preserve page:

The easy two-mile loop

Midpen's suggested loop strings several of these together. The Polly Geraci Trail climbs through the middle of the preserve and meets the Hassler and Dick Bishop trails. From there you circle around to the Dusky-footed Woodrat and Cordilleras trails and back down to the lot. Midpen calls it an easy two-mile loop. It passes the off-leash area, so it is the natural route for a dog walk.

The accessible route

The Cordilleras Trail is one of the better easy-access trails on the Peninsula. The first part runs beside a paved road. Where the two split, the trail continues at a gentle grade to a bench in a wooded spot by the creek. The road keeps climbing to the top of the preserve at a grade Midpen says exceeds 10 percent, which may be too steep for wheelchair users.

From sanitarium to open space

The open meadows at the top have an unusual past. Midpen says the land was the site of the Hassler Health Home, a tuberculosis sanitarium owned by the City of San Francisco. Midpen bought the property in 1983. Neighbors helped pay for it by approving a special assessment on themselves. The sanitarium buildings were demolished in 1985 to return the land to open space.

Look closely along the upper trails and you can still find the remains: rock retaining walls and stone steps that once led between buildings. The Hassler Trail keeps the old name alive.

Wildflowers and wildlife

Pulgas Ridge is a good early spring walk. Midpen lists Indian warrior, hound's tongue, mule's ears and milkmaids, plus three members of the lily family: fetid adder's tongue, giant trillium and mission bells. In all, the preserve is home to about 90 native species of trees, shrubs, ferns and flowers. The Dusky-footed Woodrat Trail is Midpen's pick for spring flowers. Our wildflowers guide covers timing across the region.

The trail is named for a real resident. Dusky-footed woodrats build large stick houses in the oak woodland. You may spot their piles beside the trail. Deer are common. Keep your dog from chasing them, inside the off-leash zone or not.

Rules for everyone

• Bikes: not allowed anywhere in the preserve.
• Horses: not allowed.
• Drones: drones, model airplanes and model rockets are prohibited.
• Water: no swimming, wading or any water contact in the creeks.
• Fires and smoking: both prohibited in all Midpen preserves.
• Groups: an event with 20 or more people, or one that charges a fee, needs a Midpen permit.
• Trash: pack out what you bring. Most preserves have no trash cans.

Midpen's trail closure notice for Pulgas Ridge read "No reported trail closures" on October 31, 2026. Check the official preserve page before you go, especially after storms.

Seasons, heat and fire season

Winter brings green hills and mud. Spring is the peak for flowers. Summer and early fall are dry. The chaparral on the upper slopes gets little shade by midafternoon. Walk a dog early on hot days. Foxtails dry out by late spring and lodge in paws, ears and noses, so check your dog after every walk; our dog hikes guide has more on heat and foxtails.

Fires are prohibited year-round in Midpen preserves. Midpen does not post a standing fire-season closure for Pulgas Ridge, but agencies can close land during extreme fire weather. On Red Flag days, check Midpen's closures page and our air quality guide if smoke is in the forecast.

Midpen's calendar lists guided walks here, including Halloween and Hiking Hounds on October 31, Signs of Fall on November 20 and Signs of Winter on December 2, 2026, with more nature walks in January and February 2027.

Safety

What pairs nearby

Pulgas Ridge works well as part of a half-day in the hills above Redwood City and San Carlos.

• Edgewood Park: a few minutes away off Edgewood Road, famous for serpentine wildflowers. San Mateo County does not allow dogs there, so walk the dog at Pulgas first.
• Thornewood Preserve: another Midpen preserve where leashed dogs are welcome, in the woods above Woodside.
• Town stops: our San Carlos guide covers Laurel Street for lunch after the walk.

For other hikes closer to home, see our hiking guide.

Frequently asked questions