DRAWBRIDGE, CALIF. -- For a ghost town, this decaying resort village at the southern tip of San Francisco Bay seems strangely lively.

Trains roar by on tracks that doubled as Main Street. A modern, hydraulically powered drawbridge, never opened in the three years since its installation, guards the main waterway. Barely out of sight are signs that boast of a builder's dream for a "planned community development" nearby on the bay.

New development is out of the question for Drawbridge, a thoroughly unplanned community that sprang up about 35 miles south of San Francisco on Station Island in 1876 and served as a rowdy, lusty hunting resort whose population peaked at about 2,500 on holiday weekends. It died in 1979 when the last resident moved. Vandalism, arson and nature have destroyed all but 17 of the nearly 90 homes, two hotels and countless gun clubs that once made this a hunter's paradise.

Drawbridge was a victim, some environmentalists say, of careless expansion by bayside cities and industries whose water-use and sewage-disposal practices altered the ecological balance that had kept healthy the bay and the marshland beneath the town.

"It's a good example on a small scale of what happens when man unknowingly fouls his own nest," said Richard Coleman, manager of the San Francisco Bay National Wildlife Refuge, whose 23,000 acres have included the remains of Drawbridge for 12 years.

Coleman cites other examples: the relatively low populations of ducks and shore birds, the multitude of levees that have isolated land for industrial purposes, the pollutants that mar the bay water, including heavy metals that have washed into it since the 19th-century Gold Rush.

But he also sees the success of restoration efforts, especially in the refuge's 100-acre "front yard," formerly at the heart of one of the bay's biggest salt-production operations. The idled land's salt content was so high that practically nothing grew there and birds and wildlife had no interest in it. Refuge workers started breaking through the field's levees in 1983 and used heavy equipment to crack the hard-packed ground.

By 1988, Coleman, said, they were finished, and the "resiliency of nature" took over, with rain diluting the salt, new vegetation beginning to flourish and as many as 40,000 birds feeding and resting. "I'd like you to believe it's all our doing," Coleman said. "But it's not. It's nature."

Similar restoration efforts are under way elsewhere in the refuge, and more work is proposed on some of the 20,000 acres that the refuge hopes to add to its complex.

None of that work is planned in Drawbridge, where even preservation efforts are minimal. The refuge has rejected converting one of the last 17 cabins into an environmental center, preferring not to interfere with nature. So Drawbridge inevitably will disappear.

The town has lasted longer than many people expected, its skeletal cabins more resistant than expected to the ravages of wind and water, according to refuge volunteer Patricia Stuart, an expert in the town's history. Nevertheless, the remaining cabins look vulnerable, dying in matted marsh grasses with holes in their walls and blue sky piercing their roofs, the last traces of paint rubbed away by decades of exposure.

Walking the train tracks, Stuart, 48, a social services worker who conducts tours of Drawbridge in her spare time, tells story after story. They are about the drawbridge tender who was the town's first resident, about the hotel owner who slept in the bathtub to free her own bed for overnight rentals, about the woman who watched a fish swim through her kitchen at high tide as she cooked dinner wearing "her company dress and hip boots."

"The people out here were real independent types," Stuart said, noting the absence of grocery stores, cars and, in many cases, modern plumbing, and the persistent deep mud and mosquitoes.

No roads were built, and residents thought of the train tracks as Main Street and labeled a wooden boardwalk -- the only other thoroughfare -- as B Street. Walking elsewhere generally meant tangling with thick marsh grasses, mud and high tide. Leaving town meant boarding a train to San Francisco or San Jose or sailing the family boat through the marsh toward a smaller bay town.

Most residents were devoted fishermen and hunters, some of whom downed as many as 1,000 ducks a day for sale to restaurants in San Francisco and sometimes used them to pay off wagers while gambling at the roulette wheel in Hunters Home hotel, Stuart said.

Stories of brothels and wild parties abound, as do a recent rash of claims touting the island town's love for patriotic celebrations and wholesome ice-cream socials.

"I think they're trying to clean up Drawbridge's reputation," Stuart said. "I think the truth was in between."

She said Drawbridge always had a dual personality: the family-oriented vacation playground versus the rough, hunter-dominated hangout. As the bay's population grew and civilization encroached, both personalities suffered, she added.

Expanding cities along the bay used so much water that the groundwater table dropped and Drawbridge's buildings began to sink. Measurements during the 1970s showed them settling about three inches a year into the oozing mud.

Until the advent of modern treatment plants, millions of gallons of raw sewage were dumped into the bay, with disastrous consequences for Drawbridge. The water, at its worst in the 1950s and '60s, sickened swimmers, killed fish and drove away ducks, discouraging fishermen and hunters accustomed to bagging enough to feed themselves and legions of friends.

As the regulars left, vandals grew bolder, hacking holes in homes and burning others, sometimes even breaking into occupied cabins, Stuart said. Vandalism persisted after the last resident left, and Stuart said arson is the biggest threat to the remains.

Now in her eighth year of guiding visitors and recounting the ghost town's life and death, this Texas native who moved to California in 1966 said she cannot avoid feeling that she came too late.

"I love the bay," she said. "That's why I came to this area. And I would have loved to have been out here . . . at least to have come out and been a summer person."