In Tombstone, Ariz., a writer finds that the infamy of the shootout at the O.K. Corral still wrangles visitors in

I didn’t look up when Margarita came through the door.

I was playing cards, minding my business. She was looking for company — paying company. Suddenly all hell broke loose. There was shouting and pushing, and the flash of a knife blade, and Margarita collapsed at our table.

“Call a doctor,” said the gentleman to my right.

“No need,” said the cowboy on my left. “She’s dead. Let’s play cards.”

Then we stood up and ambled away, and the small crowd sheltering from the baking desert sun chuckled and applauded politely.

The incident had been real enough, or so the story says. Gold Dollar, a prostitute in the silver mining town of Tombstone, Ariz., had indeed killed a perceived rival, who dubbed herself Margarita, over the affections and business of local gambler Billy Milgreen. But that had happened in the 1880s; 130 or so years later, our “bar” was an open set comprising a doorway, a few stools and not much else, erected in the middle of Tombstone’s Allen Street; the knife in question was plastic; and the woman taking the role of Gold Dollar was the mother of the one playing Margarita. The entire show was the work of the Tombstone Vigilantes, a local nonprofit group that, two or three Sundays a month, performs reenactments — many of which, as in the skit I had just been invited to join, address through a darkly comic lens the violence that at times was endemic in the Old West.

But this was no ordinary Sunday in Tombstone, a normally sleepy tourist town about 70 miles south of Tucson. This was part of a three-day festival of gunfight reenactments and Old West celebrations dubbed Wyatt Earp Days in memory of the town’s most famous former resident, one of several such festival weekends in the town each year. Earp lived in Tombstone for little more than two years, but in that time he saw one brother murdered and another wounded by gunfire, and participated in a roughly 30-second gunfight that killed three men and entwined the names Earp and Tombstone in history forever.

That gunfight in 1881 — in a vacant lot next to the O.K. Corral — is arguably the most famous single incident in the history of the Old West, although few are aware of the circumstances that led to it, and fewer still can recite the names of the three young men who lay dead when the shooting stopped and the smoke cleared.

“One of the most famous gunfights in the world took place right here, and we have the chance to stand on that street and do gunfights,” marvels Bill Kenney, who goes by the stage name Texas Bill when he is performing as a member of the Guthrie Gunfighters from Guthrie, Okla. “It’s pretty much the Super Bowl for Old West reenactors.”

That gunfight is also arguably the single biggest reason Tombstone, unlike so many other towns of its era in the region, continues to thrive.

“We have founded our entire economy on a 30-second triple homicide,” says Stephen Keith, an actor who plays Earp’s friend Doc Holliday at the O.K. Corral. “Without the gunfight, this town would be rubble in the desert with a pretty name.”