San Pablo Bay National Wildlife Refuge

2.65 Miles
2stars (2.33)6
2stars (2.00)
3stars (3.17)
More Info
Heading back
We doubled back on the trail towards the trailhead on Highway 37 barely seen here in the distance. (Photo by Austin Explorer)
South Slough
The official trail ends when it reaches the South Slough shown here. In the distance to the east lies Napa. (Photo by Austin Explorer)
Looking east
Looking east over the San Pablo Bay NWR from the trail. Hunters in kayaks can be seen in the distance and their shots could also be heard occasionally. (Photo by Austin Explorer)
Trail View
The Cullinan Ranch Trail sits on the line between the San Pablo Bay NWR on the right and the Napa-Sonoma Marshes WA on the left. (Photo by Austin Explorer)
Headed back
A view of the trail as we head back to the trailhead. Cougar Mountain is in the distance. (Photo by Austin Explorer)
Busy Bees
The bees and other pollinating insects were just in love this flower. Most other specimens had long ago stopped blooming. (Photo by Austin Explorer)
San Pablo Bay
At the end of the trail along the mudflats shore of San Pablo Bay. Mount Tam is off in the distance. (Photo by Austin Explorer)
Sonoma Baylands Trail
A view of the rougher Sonoma Baylands Trail. Looking west towards the Sonoma Coast and Marin County. (Photo by Austin Explorer)
Cougar Mountain
Cougar Mountain seen in the distance from the trail. Red-winged blackbirds loved the high grass on the right. (Photo by Austin Explorer)
Marin Mountains
A view from the trail looking towards the mountains in Marin County, including Mount Tam. (Photo by Austin Explorer)
The trail passes right by what may be the southernmost vineyard in Sonoma County, and the closest to the bay. (Photo by Austin Explorer)
Trail View
Most of the trail at Sears Point is flat and straight with grasslands to the north and newly reconstructed marshes to the south. (Photo by Austin Explorer)

Only showing last 12 photos. View All Photos

Log Entries
Cullinan Trail - Straight shot into the refuge area
By Austin Explorer on 11/27/2021
Rating: 3stars Difficulty: 2stars Solitude: 3stars
Distance: 3.96 Miles Duration: 2 hours, 5 minutes

Coppertone and I set out to hike another trail we had not yet mapped.  At the time we were not 100% sure whether this trail was in the state's Napa-Sonoma Marshes Wildlife Area of the nation's San Pablo Bay National Wildlife Refuge.  Mostly the Cullinan Trail exactly follows the line separating the two reserves.  Upon further research, it looks like the US government claims the trail and so we'll log it here.

There is ample parking just off of Highway 37 and an informative kiosk with a map and displays showing the wildlife who live here or pass through on their migrations.  Despite the heavy traffic on roadway, as you put distance between the cars and yourself the noise level drops a great deal.  The trail is almost straight as an arrow and the surface is a well maintained gravel roadbed.  There is a small boat launch and a separate viewing platform on the east side of the trail not too far from the trailhead.

Along the way you'll have ample opportunity to spot singular and flocks of birds either in the water or on the shore.  There were also lots of grass plugs spotting the shore on the east side of the trail as workers try to establish a ribbon of vegetation for additional cover for birds.  The official trail goes for about 1.3 miles and ends at a kayak haulout ramp with another educational kiosk.

There is a trail that continues to the west, but that is not part of the official Cullinan Trail.  In fact, it's likely leaving San Pablo Bay NWR altogether and entering the Napa-Sonoma Marshes.Wildlife Area.  The trail from this point on is overgrown but still quite manageable.  At the end of this spur sits an abandoned, dilapadated mobile home.  It may not be long before it collapses in on itseld.  This at least explains the power lines that followed the trail leading up to this point.

The trail ends here at the old homesite.  We doubled back to the trailhead and called it a day after logging nearly 4 miles on the trail.  We did pick up a few geocaches along the trail to add a little something to our outing.

Geocaching and hiking
By Austin Explorer on 12/6/2020
Rating: 3stars Difficulty: 2stars Solitude: 3stars
Distance: 3.16 Miles Duration: 1 hour, 42 minutes

We hiked along the Sonoma Baylands Trail this time around primarily for the geocaches.  There are a string of them about every 1/10th of a mile of so along the route.  In the end we logged nine caches in less than two hours.  This might represent the most we'd found in a single day ever.

Unlike our aborted trip here a couple of weeks ago when the winds were howling we had pleasant temperatures and calm air.  This trail segment in the refuge sees fewer people than some of the others so we were able to cache without having to worry too much about giving away cache locations to "muggles".

We spotted a large flock of California Quail on the trail ahead of us but they disappeared into the brush before we could get a better look at them.  They did not reappear after we passed by, which is unfortunate.  In a previous visit we spotted a hawk's nest on top of one of the high tension power line towers that crosses the trail.  It's still there and appeared to still be in use as two birds perched just above it.

A few spots along the trail were blackened by what appeared to be controlled burns.  The burned areas more clearly showed the trash that people had disposed of in the past, now primarily glass bottles and cans.  We need to make a habit out of bring a bag to pack out a bit of trash whenever we go hiking.  Every little bit would help.

Another visit to Tubbs Island
By Austin Explorer on 7/27/2020
Rating: 2stars Difficulty: 2stars Solitude: 3stars
Distance: 6.21 Miles Duration: 2 hours, 39 minutes

Coppertone and I wanted to hike a flat trail close to the bay since we had not been on the trails in quite some time. It also seemed that we'd have plenty of space to spread out from any other people we might encounter on the trail in this time of COVID-19.

We saw a hawk of some unknown variety flying back and forth high overhead in the distance. Coppertone thought it was carrying something and indeed she was right. As we got closer it was clutching either a fish or rodent in its talons. We're not sure what the purpose of carrying its prey back and forth was other than perhaps scaring it to death before eating.

We knew that the trail here is not the most picturesque, but we had somewhat forgotten how much of an abandoned industrial zone it resembles with the aggregate rock berm that blocks the view of the marshes for much of the trail's length.  Yes, you can scale the short obstacle to have a peak at any wildlife that might be there.  But the trail overall would be far superior if it were on top of the berm instead of beside it.

Mapping some missing segments
By Austin Explorer on 5/20/2018
Rating: 2stars Difficulty: 2stars Solitude: 4stars
Distance: 6.11 Miles Duration: 2 hours, 44 minutes

Coppertone and I were looking for something flater and easier after our Hood Mountain Transect last week and flat is definitely what we got here.  There were also a few trail segments we hadn't yet hiked that I wanted to map.

We set off from the Lakeville Road trailhead, which seems by far the best bet this part of the wildlife refuge.  There's a reference to parking down near Port Sonoma, but the parking area here is well used and easy to get to.

Our first leg was going down what we'll call the HQ Trail leading towards the cluster of buildings near Highway 37 that the U.S. Fish and Wildlife Service uses to help manage the property.  The path along here is very well maintained gravel.  Though one field of grassland had been recently cut others are left to grow high grass that red winged blackbirds in particular seem to love.  They were almost a contstant companion on this trail.  Turning around at the cluster of HQ buildings we were led for some distance by a killdeer who mocked injury as she coaxed us farther away from her nest nearby.

At the junction of trails near the train tracks we then headed west along Sonoma Baylands Trail.  We had saved this segment for last because we had high hopes that it would be the better of the two.  The trail surface is a seldom used jeep trail that is a bit overgrown in places.  Unfortunately, the rougher path did not translate into much better opportunities for wildlife viewing.  Low tide may have dried out some of the marshy areas to the south during our visit, limiting the number of ducks and other waterfowl one might normally see.

One thing we did see in terms of wildlife was bird egg shells and a couple of bird parts along the levee path.  We noticed that these kill sites seemed to correspond with the very large nest perched at the top of one of the high tension power line poles that cross the area.  We could see some movement in the nest, but we did not have binoculars and did not spot anything coming or going during our hike.  Perhaps mother and father pick apart whatever game they've captured within view of the nest before heading home?

The turnaround point near Port Sonoma corresponds with a jeep trail that loops around and crosses the train tracks.  It's not obvious exactly where the parking is a little further down the road.

A grand total a 6.11 miles and almost no elevation gain.  A welcome relief from the mountain climbing from last week!

Sears Point out and back
By Austin Explorer on 3/11/2018
Rating: 2stars Difficulty: 2stars Solitude: 3stars
Distance: 5.71 Miles Duration: 2 hours, 53 minutes

For our second visit to San Pablo Bay NWR Coppertone and I headed to the flat and straight Sear Point area to hike along a section of trail that was relatively recently opened to the public.  Termed the "Eliot Trail" on some maps produced by the refuge the path we chose today sat atop a levee that paralleled the railroad tracks that run through the area.  To the north some fields continue to worked but mostly for hay production these days I believe.

To the south are the wetlands that have been recreated on what used to be acres of productive farmland.  Now water, marshes and small dots of dry land sprinkled about provide shelter and feeding grounds for a large number of birds, the wildlife refuge's main customer.  From a hiking standpoint there's nothing here that's particularly gripping.  The trail is very flat and straight.  There are a few views of far off mountains such as Mount Tam and Mount Diablo is the weather permits.  But the reason for the refuge to begin with and the added interest for hiking here are the birds.

We're not birders by nature but we spotted Seagulls, Canada Geese, Egrets, Hawks, Red Wing Blackbirds, Plovers, Ducks, Terns.  The list would be longer if we had enough knowledge to differentiate the ducks and others from each other.  Suffice to say, if you like birding, you'll like hiking here.

Despite there being numerous signs indicating that dogs are not allowed on the unpaved trails in the refuge, about half of the people we encountered had dogs. One dog in particular had gotten quite muddy and wet by launching itself into the shallow muddy flats reconstructed to serve as shore bird habitat, not a doggy playground.  I'm sure the refuge personnel are stretched given current funding issues, but some enforcement of the rules is called for here.

Tubbs Island Trail
By Austin Explorer on 9/4/2016
Rating: 2stars Difficulty: 2stars Solitude: 3stars
Distance: 7.91 Miles Duration: 3 hours, 1 minute

Coppertone and I picked the trail down to Tubbs Island because it got down to the coast of San Pablo Bay and we figured a bit over 6 miles sounded about right for today.

As expected, the trail was almost entirely flat.  There were some good views of the mountains in Marin and in the East Bay off in the distance.  The birding was actually best right at the parking lot as large flocks of avocet and other species were poking around in the mud flats here.

The noise from the nearby Sonoma Speedway was an almost constant companion, but a good part of the trail was behind a berm that blocked part of the noise.

In the past the trail circled Tubbs Island once it got to the coast.  According to the NWF notices, this was no longer possible due to some channels that had opened up between the marsh in the center of the island and the Bay.  But there appears to be some culverts that were put into place recently and we were able to pass over what must have been the channel before.  The problem is that the reeds were so thick soon after that the trail seems to just disappear, so we turned back.

Recommended Item
Recommended Item 101 Hikes in Northern California: Exploring Mountains, Valley, and Seashore
Matt Heid
List Price: $17.95 Your price: $13.54 Buy Now
101 Hikes in Northern California encompasses the full spectrum of the region’s incredible natural diversity—the jagged granite of the High Sierra, crashing surf of the Pacific Coast, magnificent redwoods of the North Coast, spectacular views of the Bay Area, and much more. All trips have been thoroughly updated for the second edition, and 26 trips have been significantly expanded or reworked. Each hike description includes an easy-to-use header outlining the trip basics, driving directions, an in-depth trail description, up-to-date map, and the locations of the nearest visitor center and campground.