Hiking: San Pablo Bay National Wildlife Refuge

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Hiking: San Pablo Bay National Wildlife Refuge

The Lower Tubbs Island/Tolay Creek trail at the San Pablo Bay National Wildlife Refuge offers one of the most rewarding and unusual Sonoma County hikes, with wide open spaces just minutes away.

With its bay and tidal marsh, mud flats, wetland habitat, and open water, the refuge is an important location on the Pacific Flyway, home to large populations of resident and migrating birds at every season of the year.

Late fall through early January is a particularly good time of the year here. That's when the refuge becomes home to a huge array of migrating/wintering waterbird and shorebird species - in addition to its diverse population of resident bird, mammal, invertebrate, fish, and plant species.

And this place lives up to its name; it's truly a refuge, a protected place to shelter and breed for many species at serious risk of survival. Some species - like the California Clapper Rail and Least Tern - are listed as both state and federally endangered. One fish - the Delta Smelt - is on both state and federally threatened lists.

A great many bird species that breed here are considered by the U. S. Fish & Wildlife Service to be 'species of conservation concern.' Many more rare creatures take refuge here throughout the year. (The refuge lists recently seen birds, as well as species list for the birds, fish, invertebrates, mammals, and plants found in the refuge..)

The Hike

At approximately eight miles, the Lower Tubbs Island/Tolay Creek Trail is currently the only accessible trail at the refuge. Flat and graded, and running atop levees, it makes for easy hiking and effortless biking. The trailhead and a small parking lot are located off Highway 37, one-quarter mile east of its junction with Highway 121 to Sonoma. Park your car, walk down the dirt road past the trailhead gate and kiosk, and then follow the Tolay Creek levee past broad agricultural lands.

In late fall these agricultural lands are typically plowed and empty, stretching east as far as you can see, often under a vast blue sky. As you walk, marshy areas begin to appear. The ubiquitous salt-tolerant pickleweed, bright green in summer, turns red and orange in the fall.

Keep an eye out for smallish birds with long beaks poking around the shallows, seeking food; snow-white egrets standing aloof and looking bore; or flocks of ducks moving across deeper waters or taking refuge in tall reeds.

After a bit more than two miles a kiosk marks the entrance to Lower Tubbs Island Bird Sanctuary.

Here's an important trail note: Older maps may show this portion of the trail as a loop, but the 2014 South Napa Earthquake tore a breach in the levee, making two sections of the loop trail impassible. The U. S. Fish & Wildlife decided that this breach was best for the wetlands, and the current trail map shows the trail as it is today, without the loop section.

So when you get to the bird sanctuary kiosk, do not turn right, because you won't get very far; what looks like a trail swiftly turns into thick undergrowth.

Instead of turning right, continue along on the trail that brought you to the kiosk. You'll go past beautiful marsh scenery and onto the edge of San Pablo Bay. At that point, you can turn right, walk along the bay for a while and then head north along the levee until you reach the breach mentioned above. That's where you'll turn around and retrace your steps.

Out and back, the trail is 8.1 miles long. On many days you'll only see a few other hikers on this pathway through truly beautiful landscapes. On clear days you can see the mountains of Marin, the East Bay, and Sonoma that surround you, and possibly San Francisco and its bridges. 

Additional Information

Directions: The entrance to Lower Tubbs Island and the Tolay Creek Trail is located next to Highway 37, approximately a half-mile east of the Highway 121/37 intersection in Sonoma County. Download a map for the refuge and trail.


  • The refuge is open year-round during daylight hours.
  • Hiking and biking are permitted on the trail.
  • Dogs are not allowed on the trail.

To discover other great hikes, check out our Guide to Hiking In Sonoma County, then find more info about things to do, restaurants, and hotels & lodging in Sonoma County.

Written by Sonoma Insider Suzie Rodriguez