Don Edwards National Wildlife Refuge

As of April 15, 2019, a part of Alviso Slough Trail will be intermittently closed for repairs. Please refer to park page for updates. Easy trails and mass migrations make this one of the best birdwatching locales in the San Francisco Bay Area The ducks, geese, pelicans and egrets are only the most visible among the fascinating array of waterfowl hanging out near the Alviso Environmental Education Center of the Don Edwards San Francisco Bay National Wildlife Refuge. The trailhead near Alviso on the southernmost edge of San Francisco Bay does have issues: one is the smell, thanks to an abundance of shallow, often-still water combined with the aroma of a nearby landfill. Once your nose gets acclimated, however, you're ready for the chance to see more wildlife in an afternoon than you'd see in a month hiking the hills rimming the Bay Area. Of course if you're interested in any wildlife other than birds, you could be a bit disappointed. But how could you complain about 280 species of avians numbering in the millions on their annual Pacific Flyway expeditions? The trails on this 7-mile track are pretty basic: A section of the Mallard Slough Trail near the Environmental Education Center connected to a section of the Alviso Slough Trail. The network of levees in this section of the refuge creates nearly boundless variations, depending on how long you plan to hike. Best times to go: Migrations are heaviest in the spring and fall. Summer heat makes the hiking uncomfortable, but winter should be fairly nice.