Boston has its annual marathon, Pamplona has the running of the bulls and Laguna Niguel has ... the Mooning of Amtrak.

For more than three decades, on the second Saturday of July, hordes of Amtrak exhibitionists have gathered along the tracks near Mugs Away Saloon to expose their derrieres to passing trains.

Saturday's moon platoon was smaller than in previous years. Instead of thousands of rumps, only a few hundred were on hand for the 7 a.m. kickoff to the daylong event.

City officials no doubt cheered the depressed turnout. In recent years, they've fielded numerous reports of drunkenness, public urination and spectator-caused traffic jams.

Things got so out of hand that, in 2009, town fathers had to pass a law making it illegal to urinate in public within Laguna Niguel city limits. Ditto for drinking booze in public.

"We're hoping [the mooning] is not going to happen this year," City Manager Tim Casey said before this year's posterior parade. "We've put a lot of work into trying to stop it."

The annual event began in July 1979, when K.T. Smith told friends at the Mugs Away Saloon he would buy a drink for anyone who stepped outside and "mooned" the train. Many took him up on it, and a tradition was born.  

“We start preparing for the event several months in advance," said a Mugs Away Saloon manager who identified himself only as Hutch. "We meet with the police and the mayor to help plan everything out."

Although displaying a bare bottom is not illegal, sheriff's deputies were out in full force Saturday, patrolling Camino Capistrano to head off potential trouble.  

Shandel Schellinger said she flew in from Texas for a chance to flash her gluteus maximus at commuters.

“I am not ashamed," she said. "I want to show my backside on my birthday."

Buttock brigade member Tim Sutterland sounded equally unembarrassed. "I am proud of it," he said. “I came out here today to mark it off my Orange County bucket list.”