Despite covering a large area that has abundant wildlife, the San Pablo Baylands offer few public access points, among them the following sites (listed roughly from east to west):
Ponds 1/1a: These former salt evaporation ponds are now owned and operated by the state Department of Fish and Game. Native vegetation has begun to return to the edges of the ponds, attracting large numbers of wading birds and dabbling ducks during fall and winter. A parking turnout from west Highway 37 provides access to a two-mile road along the top of an old levee separating Pond 1 from Cullinan Ranch.
Hudeman Slough: A public boat ramp on Skaggs Island Road provides access to much of the Napa-Sonoma Marsh complex. (Access requires key issued in advance by Sonoma County Parks Department; $15 deposit). Free parking.
Ringstrom Bay: DFG’s Ringstrom Bay Unit is a good place to see ducks, raptors, beavers, and even the occasional river otter. The parking lot by the hay barn on Ramal Road (south of Highway 12/121) provides public access for wildlife dependent activities on the unit’s 400+ acres.
Tolay Creek/Tubbs Island: This unit of the San Pablo Bay NWR has a healthy population of endangered California clapper rails. The nine-mile (out and back, including loop at the end) section of the Bay Trail here runs on levees along Tolay Creek from Highway 37 out to the Bay, passing several types of wetlands. Parking and trailhead just east of Sears Point.
Sonoma Baylands: Since a dike breach in 1996, this wetland-in-transition has hosted large numbers of shorebirds as it evolves into a healthy tidal marsh. From parking on the Port Sonoma Marina access road off Highway 37 (just east of the Petaluma River), you can hike along 3.5 miles of trail, mostly on levee tops, including a recently-dedicated section of the Bay Trail.
Bahia: From the end of Bahia Drive in Novato, take the unmarked trail north. From here the path splits; head east for more than a mile along the edge of Bahia Lagoon, or continue north and west along the blue oak woodland toward Rush Creek.
Rush Creek Open Space Preserve: Five miles of trails for hikers and horses (and bikes on some segments), including a one-mile loop along the western edge of Bahia Lagoon. Pinheiro Fire Road starts at Armstrong Avenue, near the Atherton Avenue exit from 101, and intersects the Rush Creek Trail.
Deer Island Open Space Preserve: A two-mile loop around the hill that was once Deer Island offers views of the marshes between Novato and Black Point. Wildflowers such as ground iris and shooting stars are common in spring. Access from the turnout on Deer Island Lane, off Olive Avenue in Novato.