Bat Monitoring Program at the Refuge.

Did you know that you could survey for bats using acoustic detectors that record echolocation calls?  The calls are unique to each species so it's a valuable non-invasive technique to survey for bats.  This year, the Don Edwards San Francisco Bay NWR was part of the North American Bat Monitoring Program.  Staff from Bat Conservation International deployed a single recorder for one week at Bair Island and recorded two bat species: the Hoary Bat (Lasiurus cinereus) and the Brazilian free-tailed Bat (Tadarida brasiliensis).  Bats play an important role in the ecosystem by consuming insects and pollinating plants.  To learn more about bats, visit the U.S. Fish and Wildlife Service story about bats and Bat Conservation International (

Trail Closure

Mallard Slough Trail and sections of Alviso Slough Trail are Closed due to construction at Don Edwards San Francisco Bay National Wildlife Refuge in Alviso California.  South San Francisco Bay Shoreline Project (Phase I) between the Alviso Slough/Guadalupe River and Coyote Creek is underway.

For more information see the South San Francisco Bay Shoreline Fact Sheet



Visit Us

National wildlife refuges offer us all a chance to unplug from the stresses of daily life and reconnect with our natural surroundings. Surrounded by over 8 million people in the heart of the tech industry, Don Edwards San Francisco Bay National Wildlife Refuge is an excellent place to visit, whether for a short hike or a longer day outing. The refuge offers a wide variety of recreation opportunities.


Things to Do

If you have 15-minutes...

  • Start at the Visitor Center and let our friendly staff and volunteers help you plan your visit! Obtain maps and brochures. Enjoy the displays and videos in the Station. Look through binoculars to sample the birdlife in the marsh. Kids of all ages can explore the Nature Discovery Area just outside the Visitor Center.

If you have one hour.

  • Try one of the easily accessed trails near the Visitor Center.

La Riviere Marsh is 0.7 miles one way. The trail is a compacted dirt levee with a wooden boardwalk. Trail leads through tidal salt marsh salt marsh
Salt marshes are found in tidal areas near the coast, where freshwater mixes with saltwater.

Learn more about salt marsh
, restored from a commercial salt crystallizer bed. This trail is probably the best place on the refuge to view the endangered Ridgway’s rail as it comes out at low tide to feed in the muddy slough channels.

Tidelands Trail is 1-1.4 mile loop. The trail is compacted gravel on level areas and a combination of paved and compacted dirt on steep slopes. Trail traverses uplands, tidal slough, salt pond, and tidal salt marsh. Shorebirds and grebes are plentiful in the pond during the winter, and Forster’s tern and American avocets in the summer. The tidal marsh is home to the endangered Ridgway’s rail.

If you have half a day or more.

  • Take one of the trails in Fremont and then travel over the Environmental Education Center in Alviso! Several trails are available and opportunities for some excellent birding, especially during the fall and spring migrations. The Center also has a butterfly garden and a self-guided nature Play area.


Don Edwards San Francisco Bay National Wildlife Refuge is an excellent place to visit whether you are looking to take a leisurely walk, engage in some birding, or finding a new challenging trail. Whether you go on a short walk or hike a longer trail, there are over 30 miles of trails for you to explore. 

Trail Closure Alert:

Mallard Slough Trail is closed due to construction as well as sections of Alviso Slough Trail at Don Edwards San Francisco Bay National Wildlife Refuge in Alviso California.  

South San Francisco Bay Shoreline Project (Phase I) between the Alviso Slough/Guadalupe River and Coyote Creek is underway. The project, once completed, will protect north San José, including the community of Alviso and the Regional Wastewater Facility, from a 100-year coastal storm and rising seas. 

Construction hours are 7 a.m. to 5:30p.m., Monday through Friday, and on weekends as necessary, excluding holidays. Construction is scheduled to finish in January 2024. 

Other Facilities in the Complex

Don Edwards San Francisco Bay National Wildlife Refuge is managed as part of the San Francisco Bay National Wildlife Refuge Complex. Other refuges in the San Francisco Bay National Wildlife Refuge Complex include: Salinas River, Ellicott Slough, Farallon Islands, Marin Islands, San Pablo Bay, and Antioch Dunes National Wildlife Refuge. 

The Refuge Complex headquarters is located at 1 Marshlands Rd. Fremont, CA. 94555.

A National Wildlife Refuge Complex is an administrative grouping of two or more refuges, wildlife management areas or other refuge conservation areas that are primarily managed from a central office location. Refuges are grouped into a complex structure structure
Something temporarily or permanently constructed, built, or placed; and constructed of natural or manufactured parts including, but not limited to, a building, shed, cabin, porch, bridge, walkway, stair steps, sign, landing, platform, dock, rack, fence, telecommunication device, antennae, fish cleaning table, satellite dish/mount, or well head.

Learn more about structure
because they occur in a similar ecological region, such as a watershed or specific habitat type, and have a related purpose and management needs. Typically, a project leader or complex manager oversees the general management of all refuges within the complex and refuge managers are responsible for operations at specific refuges. Supporting staff, composed of administrative, law enforcement, refuge manager, biological, fire, visitor services, and maintenance professionals, are centrally located and support all refuges within the complex.

Rules and Policies

Know Before You Go



Don Edwards San Francisco Bay National Wildlife Refuge
1 Marshlands RoadFremont,CA94555
Administration Building

1 Marshlands Rd.
Fremont, CA  94555
Phone:  510-792-0222

Buildings are closed on all Federal Holidays. 

Visitor Center

2 Marshlands Rd.
Fremont, CA  94555.

CLOSED until further notice. 


Vehicle Entrance Gate

7:00 am - 7:00 pm


Open sunrise to sunset.


Don Edwards San Francisco Bay National Wildlife Refuge-Fremont
Sunrise to Sunset
Thanksgiving, Christmas, New Years Day.
Alviso Environmental Education Center
1751 Grand BoulevardSan Jose,CA95002
Bair Island
680 Bair Island RoadRedwood City,CA94603
2100 Willow RdMenlo Park,CA94025