Why would anyone want to eat oysters this small? I asked myself the first time I saw a half dozen Olympia oysters on the half shell. I was newly obsessed with learning the flavors and textures of raw oysters. Grand Central Oyster Bar in Manhattan was — and still is — the Harvard for general oyster education, so it was my classroom. Its menu lists 256 oysters, named for the places they are farmed or wild harvested. Not all are always available, but the name Olympia had a nice ring to it, so I thought I’d take a chance and try a half dozen.

From the Oyster Bar’s shucking stand came a plate of six tiny oysters, each about the size of a 50-cent piece, with meats so small they hardly qualified as morsels. But after eating a couple, I was intrigued. They had big flavor for such little guys — the earthiness of an estuary, a sweet and briny taste; nuttiness; and something metallic and coppery, like pennies in a stream.

“I don’t understand why this isn’t the most popular oyster in America. What’s not to like?”

The last time I ate at the Oyster Bar, though, they weren’t available. “Olympia oysters are not the biggest movers in this restaurant,” executive chef Sandy Ingber says. “Our customers have a hard time spending the same, or sometimes more, money on a thumbnail-sized oyster. I personally enjoy them. Our general manager adores them and really wants them to sell.” But, evidently, sell they don’t.

At the Swan Oyster Depot, a larger-than-life San Francisco hole in the wall that hasn’t changed much in over 100 years, Olys (pronounced OH-lees) have been on the menu for most of that time. On my first visit, the line for one of the dozen or so stools at the old marble bar extended out the door and down the block, but the Depot carried Olys, and I was happy to re-make their acquaintance. Now, the characters who double as countermen say they haven’t seen any in the past few years. And it’s hard to find them at the better oyster bars on either coast.

“I don’t understand why this isn’t the most popular oyster in America,” says Rowan Jacobsen, author of The Essential Oyster. “What’s not to like? It tastes like a bloody mary — celery salt, Worcestershire, spice, and a touch of tomato — and goes really, really well with bloody marys. Brunch without these is, frankly, deeply disappointing.” So, the question arises: Why aren’t Olys more popular? Where have all the Olys gone? To answer that, we have to start at the beginning.

Before the arrival of the Spanish, the Bay Area was the most densely populated region of the West Coast north of Mexico. The Ohlone tribes that were its chief inhabitants were hunter–gatherers, and their diet was rich in acorns (native oaks abound here), the seeds of grasses and forbs, waterfowl, abalone, salmon, and oysters. The oysters were the Ostrea lurida — the only oyster native to the West Coast of North America — whose range extended from southern Alaska to Baja, California, encrusting many hundreds of miles of shoreline. They were small, but easy to harvest by prying them off the shells of previous generations and picking up loose ones from the bay bottom.

In the town of Emeryville, near where the San Francisco-Oakland Bay Bridge has its eastern terminus, there’s a shellfish midden, an architectural “structure of sorts” that’s now buried under landfill and street surfaces. The mass of shells tossed there over 4,000 or more years by the Native Americans grew to be 60 feet thick and 260 feet in diameter. And that’s in just one spot. Tribes all around the Bay ate oysters and other shellfish as fast as they could shuck them, but never did put a dent in populations.

And then came the Gold Rush. The forty-niners and the millions who followed them did put a dent in the Oly population, but didn’t wipe them out entirely. What eventually killed off the oysters was hydraulic mining. Huge hoses were trained on the hillsides of the Sierra foothills, washing away lighter soil and exposing the heavier gold-bearing rocks. From 1860 to 1890, a massive amount of soil flowed down the Sacramento Delta to Suisun Bay, where larger stones and pebbles fell out, then to San Pablo Bay, where sand fell to the bottom, and then to San Francisco Bay, where silt — called slickens — smothered the oyster beds and turned a third of the Bay’s area from open water to reedy marshland. Eight times the amount of soil excavated to build the Panama Canal came down from the foothills, and that was the end of the Olys in San Francisco Bay.

Olys are at their sweetest, plumped with glycogen and fat from algae and plankton, in the winter.

While hydraulic mining was going on during the second half of the 19th century, farther north in the Puget Sound area of Washington, especially around the city of Olympia, the oysters still thrived — countless shipments were sent south to hungry Bay Area oyster fiends — and that’s where they acquired their modern name. But trouble was brewing.

During the first half of the 20th century, Pacific Northwest paper mills dumped their toxic effluents — the worst being chlorine compounds used to bleach the wood pulp — into local waters. By the 1950s, most of the rich Olympia oyster beds of Puget Sound’s inlets were also dead. And so the Olys neared extinction.

A hardy Japanese oyster that could withstand the pollution, Crassostrea gigas, was brought in and became the common Pacific oyster that’s now grown in abundance along the coast of northern California and the Pacific Northwest. Hog Island Sweetwaters, Miyagis, and oysters from many other places are all C. gigas. Kumamotos are Crassostrea sikamea, a close relative of C. gigas.

Olys appeared done for, but then in the 1960s, the environmental movement and its ecological consciousness erupted. Paper mill effluents were treated and became non-toxic. Ecologists like Betsy Peabody of the Puget Sound Restoration Fund began finding pristine beds of wild Olys growing in Puget Sound’s backwaters. The Sound’s tidal inlets nearest to the paper mills, which tended to be built closest to the open water, took the brunt of the effluent. But if you look at a map of the Puget Sound region, you’ll see that inlets extend miles away from the Sound and its beaches, and it’s in these deep, protected areas that Peabody found untrammeled beds of Olys and began seeding them in their old native habitats. It took 50 years for the paper mills’ pollution to dissipate, but today restocking those areas means Olys are reclaiming their lost paradise.

In San Francisco Bay, restoration has also begun. But Olys need oyster shells on which to attach themselves and grow to maturity, and the Bay’s original banks of shells still lie buried under Sierra foothill silt.

Two projects are helping to bring Olys back and set them to work cleaning up Bay waters (each oyster cleans more than 10 gallons of water a day). Linda Hunter, founder and director of the Wild Oyster Project, is collecting shells from restaurants around northern California and placing them in the Bay. Volunteers and scientists at the Watershed Project, meanwhile, are creating an Oly habitat. At this point, Oly restoration is for stimulating the Bay’s ecology only. There aren’t enough Olys yet to harvest for restaurants.

Eric Hyman, a board member of the Watershed Project, is also the seafood purchaser for Waterbar, a high-end seafood restaurant on San Francisco’s Embarcadero. Its C-shaped bar faces a glass case of oysters, with Olys front and center on beds of ice and rockweed. “We go to a lot of trouble to make sure we always have Olys here,” he says. "Oysters really show terroir — they’re the new wine. Olys offer something different on the palate. They’re not a bargain, considering what you get, but you don’t go to a fine restaurant looking for a bargain. It’s more about the history and the experience of something new on the palate.” In recognition of Olympia oysters’ unique flavor, Slow Food International has added them to its Ark of Taste, which is a catalog of delicious and distinctive foods facing extinction. By identifying and championing these foods, Slow Food hopes to keep them in production.

"Oysters really show terroir — they’re the new wine.

That’s helpful, but Olys can still be hard to find. “First off, Olympia oysters are awesome,” says Shane McBride, chef de cuisine at Balthazar bistro on Spring Street in downtown Manhattan. “Unfortunately, they are rather scarce on the East Coast. If I remember correctly, we have only had them a handful of times at Balthazar over the years.”

One place where it’s relatively easy to find them is in the Seattle area. Bill Taylor is the soft-spoken proprietor of Taylor Shellfish Company of nearby Shelton, Washington, where he grows and sells about 300,000 Olys a year, supplying Waterbar and many other restaurants, including his own six retail stores around the Seattle area. “We put Olys in our ‘Shucker’s Plate’ of mixed oysters, and the Olys are always a hit,” Taylor says. “It’s their unique taste, that metallic tang.”

But at the sanctum sanctorum of Olys — the Oyster House in Olympia, Washington, a long-time casual restaurant known for its endless supply of Olys on the half shell — the oysters were not on the menu. “We’ll have them in the summer,” says manager Zach Sproge.

Wait. What? My understanding is that these oysters are at their sweetest, plumped with glycogen and fat from algae and plankton, between November and March. But then by June they get spawny, and that makes them scrawny — basically a mouthful of brine with a little watery meat.

Maybe I was wrong. I checked with Tim McMillan of the Olympia Oyster Company, who confirmed my suspicions. “You’re exactly right,” he says. “By summer they are spawned out.” I checked back with Sproge and asked him if the summer Olys weren’t “creamy,” then, as bitter, spawny oysters are called. “Depends on where you get them from,” he says. I disagree — just put them on the menu in the winter. You won’t regret it.

Jeff Cox lives in Sonoma County, California, and is the author of 20 books on food, wine, and gardening. Dina Avila is a photographer based in Portland, Oregon; images taken at Olympia Oyster Bar.

Editor: Erin DeJesus