You’ve seen it from the Bay Bridge. That flat, man-made pancake of land sitting right in the middle of the San Francisco Bay, looking kinda dusty and perpetually under construction. Most people know Treasure Island for the flea markets or the killer views of the skyline, but underneath that dirt is a messy, complicated, and honestly pretty wild military history. It wasn't always a place for luxury condos and wine tasting. For decades, it was Naval Station Treasure Island, a hub for the Pacific fleet and, eventually, a massive environmental headache that the Navy is still trying to scrub clean.
It’s an odd place. Artificial.
The island was literally built out of dredged bay mud for the 1939 Golden Gate International Exposition. The city wanted an airport there, but the military had other plans once World War II kicked off. By 1941, the Navy moved in, traded some land at Mills Field (now SFO) for the island, and turned this Art Deco fairground into a primary departure point for millions of sailors heading into the Pacific Theater.
The Naval Station Treasure Island Reality Check
When the Navy finally pulled out in 1997, they didn't just leave behind some empty barracks and a nice view. They left a legacy of "superfund" proportions. If you talk to locals or researchers like those at the Greenaction for Health and Environmental Justice, they'll tell you the transition from military base to residential neighborhood has been anything but smooth.
The Navy used the island for a lot of things people don't think about. It wasn't just a place to dock ships. It was a massive training center. Specifically, it housed the USS Pandemonium, which wasn't even a real ship. It was a "mock-up" damage control trainer where sailors learned how to deal with radiation and chemical attacks. They actually used real radioactive isotopes there for training exercises. Think about that for a second. In the middle of the Bay, they were intentionally contaminating areas to teach kids from the Midwest how to use a Geiger counter.
The fallout from that—pun intended—is what makes the redevelopment of Naval Station Treasure Island so controversial today.
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Why the Cleanup is Taking Forever
You might wonder why, nearly thirty years after the base closed, we’re still talking about remediation. It’s because the Navy keeps finding things they didn't expect. Or things they "forgot" were there. For years, the official line was that the island was mostly clean, save for some petroleum and heavy metals. Then, around 2007 and 2008, workers started finding "anomalies."
That’s military-speak for "radioactive stuff we buried and didn't document well."
They found Radium-226, which was used in glow-in-the-dark gauges and ship markers. They found Cesium-137. They found bits of burnt trash that were hot enough to set off sensors. It’s a mess. The California Department of Public Health and the EPA have been riding the Navy’s back for years because the original surveys were, to put it mildly, insufficient.
Living on a Former Superfund Site
There are people living there right now. That’s the part that trips people out.
While the high-end developers are building "The Village" and sleek new towers, there is a community of formerly homeless veterans and low-income families who have been living in old Navy housing for decades. They’ve been the ones raising the alarm. They see the dust. They see the trucks. They’ve lived through the shifting stories of what is and isn't safe.
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- The Navy says the risk is "minimal" if the soil isn't disturbed.
- Residents point to high rates of strange illnesses.
- Developers say the new caps and liners make it the safest dirt in the city.
Honestly, it depends on who you believe. The science of low-level radiation exposure is notoriously difficult to pin down. What we do know is that the Navy has spent hundreds of millions of dollars digging up thousands of cubic yards of soil. They’re basically sifting the entire island through a metaphorical colander.
The Architecture of the Cold War
If you walk around the remaining parts of the base today, you can still see the bones of the old Naval Station Treasure Island. The big hangars—Hangar 2 and Hangar 3—are massive timber-frame structures that survived the 1989 Quake. They’re gorgeous in a gritty, industrial way. These were originally built for the World's Fair to house planes, then they housed Navy tech, and now they house movie sets and wineries.
Building One is the crown jewel. It’s that massive Art Deco building that looks like a command center out of a noir film. It actually was the command center. It was supposed to be the terminal for Pan Am’s China Clipper seaplanes. Instead, it became the brain of the naval operation.
What Most People Get Wrong About the "Treasure"
The name "Treasure Island" sounds like a marketing gimmick for the new condos, but it actually comes from the belief that the dredged mud used to build the island contained traces of gold washed down from the Sierras during the Gold Rush. It’s a nice story. Probably a bit of an exaggeration, but it fits the vibe.
The real "treasure" was the strategic location. During the Cold War, Naval Station Treasure Island was the nerve center for the 12th Naval District. It handled everything from personnel processing to high-level communications. If you were a sailor in the 60s or 70s and you were going to Vietnam, there was a very high chance you spent your last few nights on American soil right here, looking at the San Francisco lights and wondering if you'd ever see them again.
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The Seismic Problem
Here is something the Navy didn't have to worry about as much as current developers do: Liquefaction.
Because the island is man-made mud, it’s basically a giant bowl of jelly in an earthquake. During the 1989 Loma Prieta earthquake, the island settled and cracked significantly. The Navy barracks took a hit. To build the new towers you see going up today, engineers are using a process called "vibratory compaction." They basically stick giant vibrating probes into the ground to shake the soil until it settles into a dense, rock-like mass. It’s loud, it’s expensive, and it’s the only way to make sure the "Naval Station" legacy doesn't end up at the bottom of the Bay during the next Big One.
The Future vs. The Past
The redevelopment plan is massive. We’re talking 8,000 homes. But the shadow of the Naval Station Treasure Island remains. The Navy still technically owns portions of the land that haven't been "found clean" yet. It's a staggered handoff. The city gets a piece, the developer builds a piece, the Navy cleans the next piece.
It’s a weird tension. On one side of a fence, you have people paying $2 million for a condo with a floor-to-ceiling view of the Golden Gate. On the other side, you have guys in hazmat suits scanning the ground for radioactive buttons.
- Environmental Reports: If you’re thinking of moving there, read the "Five-Year Review" reports from the Navy. They are dry, but they tell the real story of what’s been found.
- The Museum: Visit the Treasure Island Museum in Building One. It’s small but gives you the actual context of the Navy’s impact on the Bay Area.
- Explore the Perimeter: The best way to see the naval history is to bike the perimeter. You can see the old piers where the massive transport ships used to dock.
Naval Station Treasure Island is a case study in how we treat our military history. We use the land until it's exhausted, then we spend decades trying to figure out how to live on top of what we left behind. It’s not just a construction site; it’s a 400-acre archive of 20th-century ambition and its unintended consequences.
Next Steps for Information Seekers
If you're looking to dig deeper into the actual status of the land, you need to go straight to the source. Check the Naval Facilities Engineering Systems Command (NAVFAC) website specifically for the Treasure Island BRAC (Base Realignment and Closure) documents. They host the Administrative Record, which contains every soil sample and remediation map produced in the last two decades. For a more critical perspective, look into the archives of the San Francisco Bay View, which has tracked the health concerns of the island's residents more closely than almost any other outlet. Exploring the island in person is still possible, but stick to the paved areas; the remediation zones are strictly off-limits for a reason. Understanding the island requires looking past the new glass facades and acknowledging the heavy, complicated metal that once defined this patch of dirt.