STURGIS, S.D. -- The Harley boys stood silent at the base of Mount Rushmore, squinting up at the granite faces, thinking big.

They'd all ridden their hogs down from campsites in Sturgis to marvel at the monument. Eleven thousand bikers had come in a single day, shattering the all-time attendance record at the memorial. Big, bedraggled men, most of them, with deep-baked Conan faces and bloodshot eyes and tattered hanks of oily hair blown back from the road winds. Scarred and blistered men, men with stubs and busted legs, hobbling on canes. A few biker babes in reptile skin miniskirts and Sleezy-Teez tank tops. All-American outlaws, patriotic in a hard and unsentimental way, gathered here at the great shrine of democracy, revving their unmuffled engines.

The one who called himself Mule stood off by himself, licking a cone of "Teddy Roosevelt Maple-nut" ice cream. Mule wore spurs on his boots and leather gauntlet gloves on his hands. A tattoo of a buffalo skull ran down the length of his arm. Mule had never seen Rushmore before, and he was searching for words. "What can I say?" he said. "It's awesome. It's class. It's so ... big!"

"Colossal!" said a 49-year-old Harley owner from West Berlin. "Whoever had such an idea to build something like that? It's what makes your country so great: Think big, and don't look back."

With that, the German straddled his Fat Boy, and rode the 50 miles north to Sturgis.

Every year for 49 years the little burg of Sturgis, S.D. (population 7,000), has held a weeklong gathering of bikers known as the Black Hills Motor Classic. Eleven months of the year, this is a tidy, somnolent place in the Dakota gold country. But when the Harley boys ride into town, Sturgis becomes a Gomorrah of steel, black leather and hobnail boots.

This year is the rally's 50th anniversary, and the pilgrims have turned out in record numbers: 280,000 by last estimate, though no one can say for sure. What local officials can say for sure is that this year's Classic is, quite simply, the biggest biker rally ever held in American history.

The road warriors have ridden in from all over the United States, all over the world, to take part in this rollicking fandango in the prairie. For a week now, the full length of Main Street has been lined with tens of thousands of Harley-Davidson and Indian motorcycles, parked at cocked angles from the curb. Softails. Sport Glides. Low Riders. Fat Boys. The air is choked with blue fumes and the thick smell of whiskey. Day and night, the bikers growl their engines up and down the strip with their "mamas" holding on behind. In the side streets, you can hear the constant buzzing of tattoo needles. Vendors hawk spare parts, brass knuckles, fur pelts, switchblades and endless miles of chain. Master pin stripers are out hand painting gas tanks on demand. And as the party intensifies, biker evangelists hold tent revivals to save their wicked brethren from certain destruction.

The local newspaper is calling this year's mega-gathering "Woodstock in Leathers." Bikers here feel they are witnessing a momentous piece of history, and many carry camcorders around to capture it all. Practically everybody who's anybody in the American bike world is here -- including the gangs. The Hell's Angels are here. So are the Bandidos, the Sons of Silence, the War Lords and the Gypsy Jokers. There have been a few gang-related incidents, and rumors of a major showdown between the Hell's Angels and the Outlaws were circulated after it was reported that unidentified gangs had bought up all the baseball bats on sale at a local K mart. But most people here are lone wolves who've come to have a good time and stay clear of the gang trouble. Then too affluent Harley owners (known in biker parlance as "Rubbies," for "rich urban bikers") are a big part of the scene these days.

The Classic is a celebration of an American icon, the Harley-Davidson, official bike of the U.S. Armed Forces during World War II and today the only domestic-made motorcycle. The Harley-Davidson Co. staged a remarkable comeback in the 1980s, pulling itself back from the brink of bankruptcy. You could think of Sturgis as the tribal reunion of the Harley Nation. The Harley company is based in Milwaukee, but the capital of the Harley Nation is here. It is a nation that has embraced souls as disparate as Malcolm Forbes and the Hell's Angels, a nation built around little more than love for a big machine and a shared strain of libertarian self-reliance that has its roots in the outlaw tradition of the American Wild West. "The Harley look is the look of the cowboy," says Willie G. Davidson, the bearded Harley executive in the black beret who is the grandson of one of the company founders. He and other Harley executives rode all the way here from Milwaukee. "The Harley is more than a machine, it's an iron horse, a horse on two wheels."

The Classic was started in 1938 by the late J.C. "Pappy" Hoel, a local motorcycle enthusiast who ran an Indian dealership in town. It started out as just a gathering of old friends from Hoel's riding club, the Jackpine Gypsies. Only 200 people showed up for that first rally, most of them on Indian motorcycles. There was a race, a weenie roast and a tour of Mount Rushmore, where Hoel's wife, Pearle, fixed up a big picnic spread for the men. "The rally just grew and grew and grew," says Pearle, now 85, sitting in the basement of her Sturgis home that is lined with Pappy's old racing trophies. As she reminisced about the early days, the streets outside her house thundered with Harleys. "There really is no accounting for how this thing has just mushroomed."

The Indian motorcycle company folded in 1953, but Hoel's rally had long since been overtaken by Indian's bigger American cousin, the Harley-Davidson. These days at the Sturgis rally, the old Indian bikes are treated deferentially, like aging grandfathers, but the cult of Harley rules.

In the past decade, Sturgis has eclipsed the other two biking meccas in America -- Daytona and Laconia, N.H. -- and now the rally here has a vaguely religious aura about it, like Cannes for filmmakers or Westminster for dog breeders. Sturgis is the home of the National Motorcycle Museum. A lot of bikers get married here -- more than 100 licenses have been issued this week -- and renew their vows at the next year's rally. Coming to Sturgis is like making the hajj.

"I've been hearing about this all my life," says John Brodie of Brisbane, Australia. "I can't believe I'm finally here!" Brodie sold his house in Queensland to pay for the pilgrimage to Sturgis, and arrived with a group of 50 riders from his "bikee" club, Gold Coast Hog. "Jews go to Israel, Moslems go to Mecca, and we go to Sturgis. It's something you have to do at least once in your life."

Part of the attraction is the terrain. The Black Hills region, the ancient sacred ground of the Sioux Indians, is widely considered to be America's finest riding country for street bikes. From Sturgis, the bikers can take off on day runs in any direction -- to the Badlands, the Devil's Tower, Crazy Horse Mountain, Deadwood and, of course, Mount Rushmore. "You've got to see those hills on two wheels," says. Davidson. "It's a natural for bikers because you can pick your own terrain. Highway 385 here is probably the best biking road in the country. It's magnetic!"

All during the week, the bikers attend drag races, wet T-shirt contests, motorcycle rodeos and stunt shows. The Harley-Davidson Co. has sponsored a half-scale replica of the Vietnam Veterans Memorial, which has been laid out in a park in nearby Rapid City. A biker lobbyist organization called ABATE ("a brotherhood aiming toward education") is holding a demonstration today to oppose federal legislation requiring the use of motorcycle helmets.

Peter Fonda was here earlier in the week, signing autographs for fans of his cult classic, "Easy Rider," and taking grief from Vietnam veterans still lathered up about his sister's infelicitous trip to Hanoi. The late Malcolm Forbes, who attended last year's rally with his famed riding posse, the Capitalist Tools, is here in spirit: His 200-foot hot air balloon in the shape of a Harley looms over the civic center in downtown Rapid City. Neil Diamond put in an appearance here, and there have been unconfirmed sightings of other celebrities -- Rob Lowe, Clint Eastwood, Mickey Rourke, Sly Stallone and (naturally) Elvis. There have been big-name concerts here every night, including George Thorogood and the Destroyers, the Allman Brothers, Bachman-Turner Overdrive and perhaps the ultimate biker band of all time, Steppenwolf. (John Kay, Steppenwolf's lead singer, introduced the classic "Born to Be Wild" here by saying, "Ladies and gentlemen, please remain standing for our national anthem.")

The death toll at the rally has risen to nine, most of them from highway collisions. An Australian biker was shot to death by police after he went on a rampage with a bowie knife. And there have been several reported infections caused by fly-by-night tattoo operators.

Hotel and motel rooms in the Black Hills area have been booked for more than six months, but most of the bikers are camping out in huge communal campgrounds at the edge of town with names like Covered Wagon, Wild West and Hog Heaven. But the largest and most notorious of these campgrounds is called the Buffalo Chip. More than 10,000 bikers have pitched tents here in this self-contained city dedicated to facilitating the bikers' pursuit of what Hunter S. Thompson called in his classic "Hell's Angels," "new nadirs in sordid behavior."

The Buffalo Chip has its own one-watt radio station, called Radio Free Buffalo Chip, which has been emceed all week by the legendary Wolfman Jack. The campground has its own newspaper, the Buffalo Chip Gazette, and even a Domino's Pizza shop.

At the Electric Pen emporium, tattoo artist B.J. Sloan of Alton, Ill., can give you a Viking or a scorpion at any hour of the day or night. At the Bone Factory, you can find life-size human skeletons that are, the salespeople insist, "anatomically correct." At the Softail Lounge, you can play a game of chance that involves a chicken defecating on a bingo card, or you can watch the strippers. And throughout your stay at Buffalo Chip, you can swill the official camp cocktail, "Purple Passion," a syrupy mix of pure grain alcohol and grape drink.

"It's the biggest party on the planet," says Nemo, a Harley owner from Gary, Ind., as a hard-core biker band plays the song "Boozin', Cruisin', and Losin'," up on the Buffalo Chip Stage.

"I'm going to remember this one the rest of my life. This whole scene makes Woodstock look like a dress rehearsal."