A woman walks her dog down Whipple Avenue on a Tuesday afternoon, past the used car lots, toward the little bridge that crosses the slough into Bair Island. She gets to the trailhead sign, reads it twice, and turns around. No dogs. Not "leashed dogs only." Not "dogs okay on the outer loop." None.
It looks like an odd rule for a flat, wide, obviously walkable trail two minutes off the freeway. Most people shrug it off as another overcautious parks department policy and drive to Red Morton instead. But the sign isn't bureaucratic caution. It's the fine print of a deal Redwood City almost didn't get to make, and once you know the deal, the whole island reads differently.
The Island Was Supposed to Be 4,000 Houses
Bair Island is not a park the city built. It's the largest undeveloped island left in San Francisco Bay, and for most of the twentieth century it was slated to stop being undeveloped. Leslie Salt Company diked it into three sections in the 1940s for evaporation ponds. Mobil Oil bought the land in 1973 with a housing tract in mind. By 1982, the Redwood City council had approved a residential project called South Shores, roughly 4,000 homes on marshland east of downtown.
Then it went to a citizens' referendum. The project lost by 44 votes.
That's the kind of margin that could have gone the other way with one closed business, one bad weather day at the polls, one carpool that didn't happen. Instead, the marsh stayed a marsh. Peninsula Open Space Trust bought and protected 1,623 acres in 1997, and the U.S. Fish and Wildlife Service has managed the whole complex since 1998 as part of the Don Edwards San Francisco Bay National Wildlife Refuge. A pedestrian bridge opened in 2013 so people could actually walk onto the restored interior. The final levee breach, letting Bay water back into the marsh after decades behind dikes, happened in December 2015. The trails as they exist today didn't fully open to the public until 2016.
None of that reads like a park amenity. It reads like a settlement, and settlements come with terms.
The Two Trails You're Actually Choosing Between
Once you're past the sign, the decision is simple: how far do you want to walk. Redwood City Pulse lists the trailhead at 702 Bair Island Road, open daily from 7 a.m. to 8 p.m., and from there the options split cleanly.
| Option | Distance | What you get |
|---|---|---|
| Inner Island platform | About 0.8 miles round trip | A quick loop to the closer observation deck, flat and shaded by nothing, good for a lunch break |
| Middle Bair observation deck | Roughly 1.7 miles one way (figures from POST's own trail pages land anywhere from 3.2 to 3.4 miles round trip) | A longer, fully exposed walk out into the center of the marsh, away from the freeway noise entirely |
Bring water either way. The trail is dirt and gravel, dead flat, and has no tree cover, so the exposure that makes it a good place to escape traffic sound also makes it a bad place to be caught without sunscreen at 2 p.m. in July.
What the Rules Are Actually Protecting
The no-dogs policy isn't the only restriction, and once you see the pattern it stops looking arbitrary. Off leash, on leash, doesn't matter, because the marsh is functioning as habitat for species that don't get a second chance if a coyote-shaped disturbance walks through their nesting grounds. POST's own trail notes point to Ridgway's rail and the western snowy plover, both endangered, both using this specific patch of pickleweed and mudflat. The salt marsh harvest mouse lives here too.
Paddlers get the same logic applied to water instead of land. The Bay Water Trail's guidance for the area is specific: stay on Redwood Creek, Corkscrew Slough, Smith Slough, and the open Bay, and do not enter the smaller interior sloughs that cut through the reserve itself. Landing on the island by kayak is prohibited outright. You can circle it. You can't walk onto it from the water.
Harbor seals complicate this further every spring, when they use the protected sloughs to rear their pups, which is one more reason the "look, don't touch" rule holds even for people who'd otherwise happily beach a kayak on a sandbar for lunch.
If You're Bringing a Kayak Instead of Walking Shoes
The public boat ramp at the Redwood City Municipal Marina, at the end of Chesapeake Drive, puts you on Redwood Creek with free parking and a corrugated cement launch. From there, getting around Bair Island by water is less about distance and more about timing the tide, and the local rowing and paddling club that operates out of Bair Island Aquatic Center has published its own routing logic for exactly this problem.
The mechanics, straight from that club's own guidance:
- High tide above 4 feet is the minimum for getting through safely. Below that, you'll hit shallow stretches and may need to hunt for the deeper channel by feel.
- Above 5.5 feet, the sloughs run deep almost everywhere, which is the easy window if you have one.
- Two flow restrictors built into Corkscrew Slough and Smith Slough control how water moves through the marsh. Time your crossing wrong and you're fighting current at exactly the pinch point where the channel narrows.
- Going clockwise, leave the put-in about 15 minutes before high tide as measured at Wharf 5 in the harbor. Going counterclockwise, leave about 45 minutes before high tide instead, so the current carries you through both restrictors rather than against them.
If that's more calculation than you want to do on a Saturday morning, Outback Adventures runs guided kayak trips through Bair Island and Corkscrew Slough for people who'd rather have someone else read the tide chart. Bair Island Aquatic Center itself is a membership club, and its rowing and paddling classes run through the Redwood City Parks and Recreation Department rather than as walk-up rentals, so plan a class ahead of a spontaneous paddle if you're new to the water.
The Fine Print Is the Point
None of this is friction for friction's sake. A trail this close to Highway 101, this flat, this easy to reach from downtown, would get loved to death fast if it operated on the same rules as a city park. The 44-vote margin in 1982 is the reason there's a marsh here at all instead of a subdivision. The no-dogs sign, the no-landing rule for kayaks, the tide math for paddlers threading two flow restrictors, all of it is downstream of that one close vote and the restoration work that followed it.
Next time you're deciding between the short loop and the long one, or debating whether to bring the kayak instead, it's worth remembering that the ground under your feet was one bad afternoon at the ballot box away from being someone's driveway.
If you're weighing what it means to actually live near a place like this, not just visit it, the team at Vision Real Estate spends as much time on the Peninsula's trails and sloughs as its listings, and offers a free property valuation for anyone curious what a home in this part of Redwood City is worth today.
