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



In the heart of California's high-tech industry lies a wildlife oasis in an urban sea with 30,000 acres of habitat for millions of migratory birds and endangered species. Established in 1972 through local activism, the refuge provides not only critical habitat for threatened and endangered species, but opportunities for people to enjoy the benefits of nature.

Visit Us


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

Vehicle entrance gate

7:00 am - 7:00 pm
Fremont Headquarters/Visitor Center

7:00 am - 5:00 pm
Alviso, Environmental Education Center. 


Open sunrise to sunset.

Location and Contact Information

      About Us

      The nation's first urban national wildlife refuge national wildlife refuge
      A national wildlife refuge is typically a contiguous area of land and water managed by the U.S. Fish and Wildlife Service  for the conservation and, where appropriate, restoration of fish, wildlife and plant resources and their habitats for the benefit of present and future generations of Americans.

      Learn more about national wildlife refuge
      sits on the southern end of San Francisco Bay.  It is indeed a wildlife oasis in an urban sea. The refuge, created in 1972, was largely the result of grassroots efforts by the local community to protect the San Francisco Bay ecosystem. Today, it provides not only critical habitat for threatened and endangered species, but opportunities for people to enjoy the benefits of nature.

      What We Do

      Don Edwards San Francisco Bay National Wildlife Refuge was established to preserve and enhance wildlife habitat; protect migratory birds and threatened and endangered species; and provide opportunities for wildlife-oriented recreation and nature study for the surrounding communities.

      Our Species

      Fifteen habitat types exist on the Don Edwards San Francisco Bay National Wildlife Refuge, contributing to the diversity of wildlife on the refuge. More than 340 plant species and 280 species of birds call the refuge home, and millions of individual birds fly through the area during peak migrations. In addition to plants and birds, the refuge provides habitat for fish, mammals, reptiles, amphibians, and invertebrates!

      Our Library

      Warm Springs Road Access Realignment Draft EA.pdf

      Public Review

      The draft Environmental Assessment for the Warm Springs Unit Road Realignment is now available for public review.  Download the document below. Please send your comments to: by close of business on September 12, 2023.

      Get Involved

      Whether you want to further conservation, learn more about nature or share your love of the outdoors, you’ve come to the right place. National wildlife refuges provide many opportunities for you to help your community by doing what you love. National wildlife refuges partner with volunteers, youth groups, landowners, neighbors and residents of urban communities to make a lasting difference. Find out how you can help make American lands healthier and communities stronger while doing something personally satisfying.