For one week each August, all hell breaks loose in Sturgis. In a good way. We're referring, of course, to Sturgis, South Dakota. It's the home of the world-famous Sturgis Motorcycle Rally, which attracts hundreds of thousands of hard-core bikers to a Midwestern town that usually boasts fewer than 7,000 residents.

While business owners rejoice at the influx of hog-heaven tourist dollars, local law enforcement officials must contend with the logistics of protecting what amounts to a metropolitan city. Even the most conservative attendance estimates put the Rally crowd at 350,000 strong-larger than the population of Pittsburgh. In 2005, official attendance topped out at an impressive 525,000.

Not surprisingly, the gargantuan event generates a host of big-city public safety issues, including highway deaths, heavy drug usage, firearm violations, gang-related violence, DUI offenses, and a non-stop parade of traffic violations and motorcycle thefts. Attendees flock to hotels, motels, and RV parks throughout the Black Hills, filling them to capacity for up to three weeks. Campgrounds within 80 square miles become cities unto themselves, offering temporary lodging to tens of thousands of attendees ranging from law-abiding motorcycle enthusiasts to gang-affiliated outlaw bikers.

To compensate, the Sturgis Police Department-normally staffed with 14 sworn officers-transforms into a highly coordinated, multi-agency police force. Most officers are temporary hires from South Dakota, Montana, Wyoming, and Nebraska; others come from as far away as Arizona to work as a member of the Sturgis Rally police.

"I don't know of any police department in the country that has that drastic of a transition every year for 10 days," says Sturgis Police Chief Jim Bush, who has led the agency since 1990. "The transformation is unreal-not just in the police department, but also in the community."

By the time the bikers roll into town, modest local businesses like Weimer's Diner & Donuts share space alongside scantily clad leather vendors and rowdy, open-air bars like the infamous Broken Spoke Saloon. Deep-throated Harley-Davidson "rat bikes" cruise alongside heavily chromed, multi-thousand-dollar custom motorcycles. Main Street is choked with blue-collar and top-dollar bikers, and occasionally, celebrity motorcycle enthusiasts like talk-show host Jay Leno.

"When you have that large a group of people in one place, you'd think it would be chaos," says Lisa Weyer, director of the City of Sturgis Rally Department. "I attribute that to the motorcycle community-they're a great group of people-and as far as law enforcement, they do an exceptional job."

Public safety operations in Sturgis run so smoothly that large-event organizers in other communities have sought out Chief Bush for his advice, Weyer adds.

Rally bikers are generally easy to work with, says Bush, who also admits that "any time you have that many people in one place you're going to have some crime. Throw in a party atmosphere, and it's amazing how well it goes."

Ironically, while several Sturgis PD officers are certified motor officers, "Motorcycle City, USA" doesn't support a full-time motor division. Each summer a motorcycle dealership in Rapid City, S.D., lends the department a small fleet of brand-new, sleek black FLH Road King Harley-Davidsons. The bikes are returned to the dealership when the Rally ends.

"Motor officers blend well with the bikers attending the Sturgis Rally, and the patrol motorcycles are respected by the riders," says Sturgis PD Officer Matt Veal. "Twelve hours on duty riding a motorcycle in heavy traffic is demanding. Keeping a good relationship with the bikers makes the Rally go well for both the officers and the attendees."

Rally officers work in pairs, mostly walking foot beats in a specific assigned area inside or outside Sturgis. They work 12-hour shifts, and wear the distinctive Rally uniform of gray polo shirts and black BDU cargo pants.

The other 51 weeks of the year, Sturgis PD officers patrol a quiet town with emerald-green public parks and peaceful, tree-lined streets. Surrounded by wooded areas and grasslands virtually unchanged from the days when vast herds of buffalo roamed the open prairie, the Black Hills region is prized by hunters, hikers, and history buffs alike.

The police department has been significantly professionalized since Bush first joined in the late 1970s. Back then, "basically you raised your hand, they swore at you, gave you a gun, and you went to work," he jokes.

Back then, if officers encountered a tipsy motorist, it wasn't unusual for them to pull him over, pour out his bottle of liquor, give him a stern talking-to, then send him on his way. These days, DUI is taken seriously, meth has raised its ugly head, and the Rally (which has been around since 1939, but didn't become a multimillion-dollar-generating tourist industry until 1990) will continue to grow.

In April, Sturgis police will begin accepting applications from law enforcement officers interested in working at the 2006 Rally, which will run Aug. 7-13. Applications pour in from around the nation, but it's not an easy gig to land. Officers who have worked past rallies are given first right of refusal, and they rarely say no.

"Camaraderie. I think that's what brings a lot of them back every year," says Bush. "For 10 days each year, we become one police unit."

Bryn Bailer, a former newspaper reporter, is a contributing editor for Police. By night, she is a member of the Tucson (Ariz.) Police Department Communications Division.