The Bay Area's only ghost town - a once-thriving party destination known as Drawbridge - is slowly sinking into the South Bay mud.

The slide of the little hamlet near Alviso will continue until the last chimney slips below the muck - with blessings from the town's current landlord, the U.S. Fish and Wildlife Service.

"It's a landmark, so we're not going to do anything to accelerate its decay, but we're not going to prevent it, either," said Eric Mruz, manager of the Don Edwards national wildlife refuge, which encompasses Drawbridge. "We're letting the buildings return to the marsh."

The last resident departed from Drawbridge in 1979, leaving behind about 25 homes, hotels and gun clubs to sink into the muck a few miles from downtown San Jose.

The once-lawless town, now in the middle of a $400 million effort to restore South Bay wetlands, is off-limits to the public. The only way to reach Drawbridge - if and when Fish and Game officials agree to escort visitors there - is by boat ride down Artesian Slough and a half-mile tromp, in hip waders, through the pickleweed.

But as Drawbridge sinks, a different kind of wildlife is returning. Ducks, geese, raptors and shorebirds, once greatly diminished in the area because of the salt flats, now fill the skies as the levees come down and the tidal waters pour in.

"What got people out here to begin with - hunting and fishing - was the abundance of wildlife. Now we're seeing the final chapter," said John Bourgeois, head of the South Bay Restoration Project. "As this town sinks away, we're able to bring this area back to its glory."

Drawbridge sprung into being in about 1880, when the railroads hired an operator to raise the train drawbridge over Coyote Slough for shipping traffic.

Soon the operator's friends joined him at the muddy outpost at the far reach of Alameda County.

Before long, hunters and fishermen began flocking to the town on weekends, swelling the population to nearly 1,000.

By 1926, Drawbridge had 90 buildings, most of which were on stilts so they weren't washed away by the tides. Residents had wells and electricity, and built outhouses over the sloughs.

The town had no roads but was big enough to have two neighborhoods, South Drawbridge and North Drawbridge. The south was wilder and mostly Catholic, and the north was thought to be more "stuck-up" and predominantly Protestant, according to a history of the town compiled by local historian Eric Carlson.

"Well, there was some out-and-out feuding, like Bill Holden and his brother Lou. They went for years without speaking, shielding their faces with a newspaper," said Charlie Luce, Drawbridge's last resident, as quoted in "Drawbridge, California: A Hand-Me-Down History" by O.L. Dewey.

Residents had "tide parties," in which they'd row to neighbors' houses for parties during high tides. Children rowed to school in Alviso, a few miles away.

"The heyday was in the 1920s," said Diane Curry, curator at the Hayward Area Historical Society. "But it was kind of out in the boonies, so it was probably more of a weekend place."

By the late 1930s, Drawbridge and Alviso both began sinking as San Jose pumped water to accommodate its building boom.

Also, in those days burgeoning San Jose dumped its raw sewage into the sloughs, making Drawbridge a much less attractive place to spend a weekend.

The salt flats didn't help, either. As salt production increased in the South Bay, waterfowl sought more hospitable terrain and fled, leaving hunters without much to hunt.

By 1955, the trains ceased stopping at Drawbridge, and most of the residents drifted away. The last residents were Luce and Nellie "Shotgun" Dollin, so named for her tendency to fire at trespassers.

Today, about 20 buildings remain, scattered a half-mile or so along the train tracks. Some of the buildings have sunk up to their rooftops; others appear dilapidated but otherwise high and dry.

Owls, bats, endangered harvest mice and clapper rails now reside in the old gun clubs, and the old pathways are covered in pickleweed and grass. The only sounds are quacks and honks from waterfowl.

Just across the mud flats one can see the shiny high-rises of downtown San Jose, homes creeping up the Fremont hills, and one of the most modern, civilized places on Earth, Silicon Valley.

The story of Drawbridge is, in many ways, the story of the West, said San Jose State University history Assistant Professor Glen Gendzel.

"Ghost towns are a residue of the heritage of speculation, the boom and bust cycle," he said. "They're spectral reminders of dashed hopes, when growth went in another direction."

The Bay Area is filled with modern ghost towns, he pointed out, such as vacant office buildings, abandoned housing developments and other byproducts of the Great Recession.

So what should be done with Drawbridge? The federal government won't restore it because of the cost, and the agency is not eager to establish a tourist attraction in the middle of a sensitive wetland, Mruz said.

Leaving Drawbridge alone is probably the best option, Gendzel said.

"It's a reminder of how ephemeral the hopes and dreams of the West can be," he said. "We take gambles, and sometimes they don't work out."