By 7 o'clock, the Monday-night scene was in full swing: A college student with a mohawk pushed through the door for the $5 pizza-and-pitcher special. A woman with white curls laughed with other locals at the bar, and in the back, a skinny guy in a cheap dress threw darts.

It's been like this for decades at the Green Door Tavern -- busy, with an eclectic, tipsy crowd. But the smoky room in Park Hall is one of the last of the old St. Mary's County bars, a holdout in a place where the changing culture and crackdowns on drunken driving have put a serious dent in its hard-drinking reputation.

Twenty years ago, St. Mary's had more liquor licenses per capita than anywhere else in Maryland, according to a grand jury investigation, and the highest percentage of driving deaths caused by alcohol.

The traditions ran deep: It was a place where, during Prohibition, bootleggers rolled barrels of whiskey off the wharves; where in the 1940s, the Patuxent River Naval Air Station opened and test pilots crowded into the Roost; where in the 1950s and '60s, slot machines in bars gobbled and spat quarters; and where, in the '80s, bartenders still sold cocktails-to-go in paper cups.

But things are changing, as the county's economy transforms and warnings about health and drunken driving take hold. Farmers and watermen are becoming outnumbered by newcomers to the county -- a large number of them well-paid scientists and executives working for defense contractors drawn by the Navy base. People now are more likely to head to the gym or a chain restaurant with their family after work, rather than hang out at the neighborhood hole in the wall.

"It's like every place now," said T.V. Long, who has lived in St. Mary's all his life.

Duke's bar closed years ago in Leonardtown, replaced by a French restaurant with lace curtains. The Wharf burned down, and now luxury condominiums are rising on the waterfront land. The Victory Bar and the Two-Spot, and most of the topless bars that sprang up near the Navy base, are long gone. Even the taverns with ballfields out back have been shutting down. Two of the biggest are up for sale.

Here and there you can still see the signs of the old hard-drinking St. Mary's -- in dark bars, some without signs, most without windows, places with linoleum tiles that smell like old beer, red vinyl stools with stuffing poking out, cigarette scabs on Formica, peanut shells on the floor, friends who grew up together, dogs sleeping under pool tables.

Yet it's nothing like it was back in the day.

The Old Gum Tavern was built in rural western St. Mary's back in the 1930s after a big hurricane hit, said Long, who spent much of his youth there. Torn-up piers floated down the Potomac and were nailed together into a rough wooden structure with a hole in the floor to throw the whiskey bottles down.

Long's parents dressed up to dance the Charleston at the Old Gum. Farmers, watermen and laborers in the area found their way to the neighborhood bars most afternoons. "It was nothing for these guys to drink half a fifth of liquor and smoke two or three packs of Pall Malls," Long said. "Some people drink coffee. These guys had a [shot]."

The fights were legendary, and a few ended with gunshots. "Some people would say, 'Don't go into the Old Gum -- they'll rip your head off,' " Long said.

But it could be a friendly place, too, with a ball team, ice cream for the kids and nickel horse-race games. As a teenager in the '60s, Long and his friends would push open the double swinging doors, put money in the jukebox, get a $2 bucket of scalded oysters, flirt with girls. The Old Gum was one of nine bars in a seven- or eight-mile radius, Long said, at a time when there were only a handful of general stores and nothing much else in the area, so sometimes they'd pick up a go-cup and head up the road.

"Might be a little drag race here and there," he said. "Wasn't no traffic."

As the county grew, though, the roads got busier, and new people moved in. Some of the old traditions started to seem dangerous.

In 1984, a St. Mary's grand jury investigation, prompted by concerns about underage drinking and traffic accidents, found that 83 percent of driving deaths so far that year were alcohol-related. The previous year, it was about 75 percent; statewide, it was about 50 percent.

The county had one liquor license for about every 300 people. At the same time in Montgomery County, it was more like one for more than 1,100 -- and Montgomery didn't allow what the St. Mary's grand jury called the "local innovation," the go-cup.

Many bars, and most liquor stores, in St. Mary's sold alcohol at drive-in windows. Teenagers told the grand jury that they could buy alcohol anywhere. And there was no record of any violations, said Herbert Winnik, a St. Mary's College of Maryland professor who served as foreman.

Since then, the county Alcohol Beverage Board has grown and gotten tougher. The number of liquor licenses dropped -- from 210 in the mid-1970s to 165 now -- with a population that has nearly doubled to more than 90,000.

Bar owners began to worry about liability. The police force grew and so did enforcement, with checkpoints and prevention programs. A local paper started printing the names of people stopped for driving under the influence -- often with nasty asides.

Now bartenders can call a taxi for plastered customers and give them a voucher from the county for the ride home. And the go-cups were banned in the mid-1980s.

Drive-through liquor stores aren't allowed in Virginia, and seven counties in Maryland have banned them -- including St. Mary's, where a few remain but no new ones can open.

Police sometimes hide in the cornfield by the Green Door to watch for weaving drivers headed back to nearby St. Mary's College, said Brian Tarleton, the owner.

There are still drunk drivers out there: Over the past decade or so, alcohol played a part in about 140 accidents and six deaths a year in St. Mary's, according to the State Highway Administration. That's about half of all the traffic deaths in the county in that time; statewide, the proportion was less than a third.

But that's lower than it used to be in St. Mary's, and many drivers are more aware. Long said he's glad to see DUI stops and restaurants carding, and like most people he knows, he'd rather drink on his big waterfront deck now. "The law -- it's not worth the damn trouble you can get into," he said.

A few places such as the Green Door stay hopping with loyal old-timers and college students like the guy who stopped by after theater rehearsal in a dress, part of his costume.

As for the Old Gum, after passing from owner to owner, it finally shut down.

When builder James Horstkamp started working on it after it had lain empty a decade or so, he found about 700 empty whiskey bottles under the floor. Five or six people would stop by every week to tell him stories, about pool cues flying in flights or the floor shaking under all those dancing feet.

He's not sure what will happen to the Old Gum. Maybe someone will want to open a bar there again, he said. Or maybe he'll turn it into an office building.

The Green Door Tavern, on Route 5 in Park Hall, is a favorite watering hole for locals and students at nearby St. Mary's College of Maryland. Kim DeBoy hustles to get a pitcher to a customer during the evening rush.Tony Evans, left, and David Norris sit at the bar during happy hour at the Green Door Tavern in St. Mary's County.