Alviso Marina and Salt Pond A12 (Winter)
by John Hurley
This park can be good as a quick stop or a day-long adventure, with views of all different kinds of waterfowl, marsh dwellers and shorebirds. Walk along the boardwalks to listen to the noisy song birds and rails, stand at the boat dock to scan Alviso Slough for grebes and other waterfowl, or head out to the salt pond for mesmerizing murmurations of shorebirds and an impressive number of ducks.
Trip Covers: November – April
Key Birds: Northern Harrier, Marsh Wren, Lincoln’s Sparrow, Common Yellowthroat
How to Bird
Alviso Marina County Park is located where the Guadalupe River flows into the Alviso Slough before heading out to the bay. This park features a boat launch and a small marsh with boardwalk trails. The adjacent salt ponds are part of the Don Edwards San Francisco Bay National Wildlife Refuge. This guide covers the county park and one of those salt ponds, Pond A12.
Male Northern Harrier flying low over the marsh. Photo by John Hurley.
Choose between two routes (or do them both): a one-mile walking route, the Marina and Marsh Loop; and a longer 3.8-mile route, the A12 Loop, that can be hiked or biked. On the Marina and Marsh Loop you will see marsh birds and some waterfowl. For closer looks at some of the gulls and shorebirds, the A12 Loop may be the way to go. Once you leave the area near the boat dock, the trails have very few people on them. A scope is recommended to view some of the more distant gull flocks.
Marina and Marsh Loop
Start this short loop with a 300-yard walk from the parking lot to the boat launching dock. Along the way, you will see Golden and White-crowned Sparrows darting across the road and into the brush. Nestled in the reeds in the midst of other brush are Black-crowned Night-Herons. You may also see Song Sparrows, Savannah Sparrows and Anna’s Hummingbirds.
Alviso Marina boat launching dock with a northwest view of the Alviso Slough. Photo by Eve Meier.
View from the boat launch parking area southeast towards the Guadalupe River. Photo by Eve Meier.
At the boat launch ramp, look southeast along the channel towards the Guadalupe River for Canvasbacks and Eared and Pied-billed Grebes. There is a short spur of the trail that goes along the Guadalupe River if you want a closer look at something you saw there.
In the reeds around the boat dock, you may see Common Yellowthroat, Spotted Sandpiper, and Greater Yellowlegs. In addition, look for Great Egret and Snowy Egret. Often, a Northern Harrier will fly along the channel and over the marsh.
The channel northwest of the dock is the start of the Alviso Slough. Here you may see various waterfowl, including Greater and Lesser Scaup, Ruddy Ducks, Bufflehead and Common Goldeneye.
Female Common Goldeneye by John Hurley
After taking in the sights at the boat launch ramp, walk back towards the parking lot and head northwest toward the two ochre-colored gates on the boardwalk and Salt Pond A12. When walking along the boardwalk, stop at the little channel that runs under the boardwalk and look up and down for Common Yellowthroat and listen for Marsh Wrens, Sora and Virginia Rails.
Boardwalk with two ochre-colored gates. Photo by Eve Meier.
Walk north towards Pond A12. Take a right turn and walk east along A12, looking for shorebirds and gulls such as California Gull, Herring Gull, and Short-billed Gull. At the east end there is another small pond and an observation deck. From the deck you can look down into the marsh to get views of some of the birds you may only have heard before. Walk south back to the picnic area and restrooms. At the end of the walk, check the L-shaped boardwalk in front of the restrooms for Marsh Wrens and Song Sparrows. In years past, a Swamp Sparrow was seen around this L-shaped boardwalk.
Common Yellowthroat by John Hurley
A12 Loop
As it says on the US Fish and Wildlife site, “10,000 ducks! And solitude!”. This may not be too far off the mark, depending on where the ducks are in migration. This section describes a counterclockwise trip around Salt Pond A12.
To reach the trailhead from the parking lot, go east toward, then past, the restrooms. The trail starts at the metal gate (trailhead shown on map). When you go through the gate, the railroad tracks and a small pond are to your right. Look in there for gulls and shorebirds such as Least Sandpiper, Black-necked Stilt and American Avocet.
Continuing north for about 0.7 miles, you come to the intersection of Ponds A12, A13, and A16 (#1 on map). To the right (east), the Don Edwards Environmental Education Center can be seen off in the distance. This is a good place to see lots of different gull species and shorebirds. Occasionally, a Peregrine Falcon may be seen waiting on one of the small islands.
Peregrine Falcon by John Hurley
When you get to Waypoint A12-2 (#2 on map), you can take a 0.3-mile detour north to check out Salt Pond A14 (#3 on map). This trail is very narrow, so take care if you are biking. After the detour, continue on your loop, keeping Pond A12 on your left. Make a left hand turn when you reach Waypoint A12-4 (#4 on map) to head back towards the marina.
Any of the ponds may have vast numbers of waterfowl, including Ruddy Duck, Bufflehead, Northern Shoveler, and American Coot. For larophiles, there are usually hundreds of gulls, including California Gull, Ring-Billed Gull, Glaucous-winged Gull and Short-billed Gull. You may see grebes such as Western Grebe, Eared Grebe and possible Horned Grebe or Clark’s Grebe. Shorebirds such as Least Sandpiper, Dunlin, Dowitchers and Yellowlegs can be seen in the ponds on the way back.
Ready for More?
The full Alviso Slough Trail encloses Ponds A9-A14 and is 9 miles long. The Mallard Slough Trail is accessible from this location as well. You can reach it by crossing the train tracks on the east side of Pond A15 (see map). That trail encloses Pond A16 and goes past the Don Edwards Environmental Center, with views of A17 and A18.
Interactive Map
Directions
From Highway 880: Take Highway 237 (Alviso-Milpitas Road) west to North First Street exit. Turn right on North First Street (which becomes North Taylor); turn right on Gold Street, left on Elizabeth Street and right on Hope Street. The county park is at the end of the road in 0.1 miles.
From Highway 101: Take Highway 237 (Mt. View-Alviso Road) east to Great America Parkway exit. Turn left onto Great America Parkway, turn right on Gold Street Connector, left on Gold Street, left on Elizabeth Street and right on Hope Street. The county park is at the end of the road in 0.1 miles.
Address: 1195 Hope St San Jose, CA 95002. Latitude/Longitude: 37.429895, -121.979785
Parking: Large paved parking lot. Note that there is limited street parking if you want to explore before the auto gates are open.
Fees: There are no fees collected at this time for vehicle entry.
Public Transportation: Nearest VTA bus stop is ½ mile away on Gold St and N Taylor St.
Park Hours: The park is open year-round from 8 a.m. to sunset.
Facilities: The restrooms are open and clean.
Trip Mileage: Approximately 1 mile for the short loop including the boat ramp and the marsh boardwalk; 3.8-mile optional loop around Salt Pond A12.
Trail Conditions and Accessibility: The trail around Pond A12 is flat, hard-packed sand and dirt. It becomes muddy when wet, then forms hard ruts when it dries. Most of this trail is wide, but the segment of trail between Pond A12 and A13 is narrower and fairly rutted. The segment of trail from the northwest corner of Pond A12 going north to see Pond A14 is particularly narrow and bordered on the left by the bay. The trail around the pond has no benches and is exposed to the elements, with no sources of shade or shelter.
Bikes: The loop around Pond A12 is a great trip to do via bike! While bikes are allowed on all pathways and trails in the park, please walk your bikes on the boardwalks.
Dogs: Dogs are allowed in the County Park's pathways and picnic areas, but are not allowed on the trails, levees and boardwalks.
More Information
Alviso Marina County Park Map
Don Edwards NWR Construction Updates
eBird Hotspot: Alviso Marina County Park
eBird Hotspot: Salt Pond A12
More Resources
For more trips like this one, visit Self-Guided Field Trips.
Visit the SCVAS Birding Resources page for more information on where to bird, our birding community, bird identification resources and more.
Read “What to Look for Now” by SCVAS Executive Director Matthew Dodder.
Banner Photo Credit: Eared Grebe by John Hurley
Last Updated: 3/23/2022
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