As temperatures cool and daylight fades, the clothes start to come off and the partying beings at the Sturgis motorcycle rally. Dusty Parker of Rapid City says nighttime at the rally is more intense and it's all about "girls, beer and concerts."

"People are more intense; whatever they do is times 10, they let loose and do crazier stuff than they would normally do," Parker said. Early evening on Monday, crowds filed into the Glencoe CampResort before the KISS concert. The women behind the bars reminded people to buy cold beer and lines formed in front of the beer tents and food stands.

Alan Rensing of Cincinnati said the nightlife at the campground for his first time at the rally is "pretty wild." "It's more of a carnival atmosphere, with nudity and bikes," he said. Timmy Hemphill of Wyoming has been coming to the rally for five years and said most people ride through the hills during the day before returning to Sturgis or their campsite to clean up and get ready for the nightlife festivities. At night, he said people tend to get "gutsier." "Toxic, alcoholic, inebriating libations remove all inhibitions and a good time is had by all," Hemphill said.

Downtown, Marcos Avila, from Mexico, says everybody "kind of misbehaves." He said One-Eyed Jack's Saloon is his favorite place to be downtown. At night, he notices the women dressed provocatively and the men taking body shots at the bar. Avila is camping in a yard on Junction and said he would rather party downtown than at a campground outside of Sturgis.

Mike McGinnis of Wyoming said he's been attending the rally since 1958 and One-Eyed Jack's is the place to be. "Everybody here is different, it's cool," he said. "It fills up, there are 50-60 bartenders, it's the biggest, with the most people." Even after Kid Rock stopped playing Monday night, crowds gathered at the Buffalo Chip to see women wrestling, girls breathing fire and tires smoking on the Burnout Bridge.

Scott Ryan rode 1,900 miles from New Hampshire to attend the rally and said nighttime is when people are more relaxed. He said the party starts after the sun goes down and stops as soon as people "feel it's appropriate." "Everybody is doing their own thing; at night a lot of people really start being themselves," he said. "The heat during the day tempers the debauchery."