Close to midnight on a Saturday evening late this summer, a police helicopter crested over a ridge in a desert canyon near Salt Lake City, descended into a low hover over a private ranch, and lit up the area with floodlights. Below, about 1,000 young people were dancing to electronic music at a legal, long-planned rave. They had no idea the police in the sky were armed to teeth and had them surrounded.

Suddenly, cops on the ground stormed in to stop the whole thing. About 90 uniformed officers, equipped with guns, dogs, Tasers and tear gas, marched like a conquering army into the crowd. They shut off the music and ordered people to leave; anyone who gave them trouble -- anyone who merely asked what was going on -- was dealt with harshly. People in the crowd reported being brutalized, terrorized with guns, dogs and other weapons. A two-minute video of the event shot by a videographer named Jeff Coombs shows officers surrounding selected members of the crowd, forcefully pushing them to the ground, and arresting them.

Raves have been a cultural phenomenon for more than a decade. The high-energy dance parties, both organized and improvised, have taken place in countless places -- clubs, warehouses, rooftops, ranches -- across the country without incident. Yet raves clearly upset something in rural Utah. Utah County Sheriff James Tracy says he broke up the rave to stop rampant drug use, sexual abuse and dangerous health conditions. But in the month since the raid, details have emerged in interviews with attendees, in press reports and in court that vindicate the ravers and paint a disturbing picture of excessive police force.

In August, rave organizer Brandon Fullmer filed suit against Tracy, asking a federal court to prevent the Utah County sheriff and other officials from closing down any future legal raves. But despite his outrage over the sheriff's actions -- and the larger outrage in the world beyond Utah -- it now appears that the authorities in the county will face no trouble for the raid. County officials have sided with Tracy and on Thursday a federal judge in Salt Lake City denied the rave promoters' demand to enjoin the sheriff from closing down any future legal raves in Utah County.

"The sheriff has essentially said that we don't want these kinds of concerts in our county," says Brian Barnard, Fullmer's attorney. "They don't want concerts for young people in our county -- they don't want electronic music, kids hanging out all night long. It's a prejudice and a fear of young people."

Folks uninitiated in the rave scene will be surprised by the logistical complexities involved in putting on an all-night dance party for a couple thousand people. A good rave with popular DJs and a great sound system requires the kind of planning and attention to detail that would do a White House advance team proud. This is the sort of rave that Fullmer, a record-store manager and veteran Salt Lake City party promoter, began planning in April, four months before the event was to be held.

Fullmer, who says he has put on more than 100 parties during the past decade, thought of everything. The venue he chose for his Aug. 20 rave, a 350-acre parcel of land owned by local ranchers, is a prized location for concerts. Set in a section of Spanish Fork Canyon called Diamond Fork, it's far from any populated area, giving ravers a great deal of space, and peace of mind, to dance, to make noise, to camp out, to have fun. Because the party was to last all night -- attendees were encouraged to bring their camping gear -- Fullmer outfitted the place with a host of amenities to keep kids happy and safe. He rented dozens of portable toilets and contracted with a team of security guards and with Spanish Fork Ambulance, the local emergency medical team, to staff the rave. Early in August, Fullmer applied for and was granted a mass-gathering permit for the rave from the Utah County Health Department.

Most important, Fullmer saw to the music. He hired a team of stagehands and audio technicians -- there would be two simultaneous stages -- and assembled a line-up of drum 'n' bass stars from around the world, including DJ Craze, from Miami; Seattle's DJ Syze; Spor, from London; and Atlanta's Evol Intent. Fullmer began selling tickets at his record store for $15 (tickets purchased at the gates were $25); he called the rave Versus II, a kind of sequel to a previous rave he'd organized -- only, his advertisement promised, three times better.

In the weeks leading up to the rave, while Fullmer carried out plans for the event, Sheriff Tracy set his sights on disrupting it. Tracy is suspicious of raves; he says they are a breeding ground for drug and alcohol use, for sexual assaults on women, and for violence of other kinds. This is not, he insists, just an idle belief on his part -- Tracy says previous raves within his jurisdiction have caused just this sort of trouble, so when he became aware of Versus II, he knew the crowd would be up to no good.

Versus II opened its gates at around 9 p.m. on Saturday evening. In the three hours before the cops burst in, between 800 and 1,000 people streamed into the place. According to several members in the crowd, there were no sexual assaults or violent incidents of any sort. Mark Byers, one of the half-dozen emergency medical service officers present, attests that there were no health problems. Security personnel at the gates did search ravers as they came in, and according to Fullmer, various types of contraband were confiscated. The rave then uncoiled as planned -- lights pulsed, music blared across the canyon, and people danced.

Tracy, though, had no eye for the entertainment. He had inserted undercover personnel in the crowd, and in the three hours after the gates opened, he says, the agents made five purchases of illegal substances. Drugs were all over the rave, he says, and so he decided to act. He called in the helicopters and ground troops.

For ravers in the crowd, the first sign that anything was amiss came with the lights of a chopper cresting over a nearby ridge. "It gets to be about 11:30 and we all see this light coming from over the mountains and it gets closer and closer," Ashley Hawker, Fullmer's girlfriend, described in an e-mail. "Then it starts shining its light on the entire crowd. That's when I look to my right and ... I see a guy dressed in all green camo and carrying a gun and wearing a helmet. I thought my eyes had deceived me but following right behind him are more big green men carrying fully automatic guns. My whole body starts shaking uncontrollably." Many ravers emphasized the speed with which the police descended; one minute, everything appeared normal, and the next minute, the crowd was surrounded by uniformed men with guns. "It was a military siege," says Jessica Riley, a 25-year-old raver and student at Humboldt State University who attended the party that night. "The light is sweeping all over the ground, and there are all these kids standing there trying to figure out what is going on. The quickness shook a lot of people."

Bewildered as they were, many ravers immediately began to document the raid. "Every single kid with a camera and a phone pulled it out and started taking pictures," Riley says. The move seems to have infuriated the cops. On Coombs' video, you can hear the officers yelling at him to turn off his camera, and on a discussion page documenting personal accounts from the raid, several people say they witnessed kids getting attacked by the cops for refusing to give up their cameras.

Once they were among the crowd, officers directed people toward the exits -- sometimes refusing to allow them to pack up their camping gear -- and began to deal harshly with anyone who resisted. Alaisha Matagi, a 24-year-old woman in the crowd, later posted online that when an officer "in full army attire" told her to leave, she asked, "What's going on?" "At which point I was brutally attacked," she wrote. "Thrown to the ground and in the scuffle punched in the face by SWAT. That was not it either. I suppose I posed some threat as another SWAT member rushed over to subdue me to the ground putting his knee in my back and arresting me. At that point I am screaming to a patron 'what's going on?' He is just as confused as I am. At that point another SWAT member came over and kicked me in the leg. Let me tell you that I also only weigh 130 pounds. I had three grown men attack and beat me and throw me to ground for absolutely no reason at all. Not to mention being dragged to a van and violently being tossed in and taken to jail. Fined for resisting arrest and another outrageous charge [failure to obey police]." Matagi's account is supported by Coombs' video -- she's the woman in the red-hooded sweatshirt being held to the ground by many officers -- as well as by several witnesses who spoke to Salon.

In interviews and on message boards, other ravers described additional instances of harsh tactics by the police. Some people say tear gas was used; others say Taser weapons were drawn and fired. Several in the crowd point out that in infrared footage of the scene shot from the police helicopter that night, an officer in the air can be heard directing officers on the ground to fire a Taser at some people. And virtually everyone who spoke to Salon said they saw officers drawing and pointing automatic weapons at ravers, and that this tactic really freaked people out. Heath McBee, who owns an audio firm called Euphoric Beats and was handling the sound that evening, says he was resting on a cot in his truck when officers slammed open his doors and began yelling at him to shut the music down. "I woke up to an M-16 pointed at me," McBee says, like nothing he'd ever seen in nine and a half years of working raves.

The sheriff says the ravers are mistaken. "We don't have any M-16s," Tracy says. He acknowledges that officers at the rave did have Taser weapons as well as tear gas and either sidearm pistols or rifles, but that equipment is standard issue for all police officers, he insists. "It would be no different if a guy got stopped on the road." And even though officers carried those weapons, they didn't use them, the sheriff says. In a couple of instances officers pointed but did not fire their Tasers, according to Tracy; but he says he's aware of no instances in which officers pointed guns or used tear gas.

Tracy also defends the officers' practice of surrounding ravers and pushing them to the ground, as we see them doing to Matagi in the Coombs video. "That's standard procedure," Tracy says. "What we do is take them to the ground, wrestle them till we get their hands. Now you see a guy with a knee on her back and you ask why you need to do that. But officers have been shot and killed and stabbed by people who weighed 90 pounds and were actively resisting arrest." Tracy says the takedown procedure was used sparingly -- just two or three times -- that night.

Not only does Tracy believe his officers acted with restraint, he also says that his decision to shut down the party can be seen, in retrospect, as wise. Many drugs were confiscated at the party, he says, and of the 30 or so people arrested that night -- most for disobeying or resisting officers -- a handful were charged with possession.

The rave promoters say Tracy's drug argument is bogus. They say the bulk of the contraband was in possession of the security guards, who had confiscated it from the crowd. Tracy doesn't buy the story. The security guards' possession of drugs was still illegal, he says, as they should have notified police of the contraband as soon as they discovered it. Tracy also says that he personally found drugs as he walked around the grounds after the raid." I picked up a bag off the ground," he says. Tracy says he found marijuana, cocaine, Ecstasy, methamphetamines and mushrooms. "For the size of area we picked those up in, I consider that a large amount."

The sheriff claims ravers were dangerously high. One woman -- whom Tracy did not name -- was found to be close to overdosing on Ecstasy, with a resting pulse rate of 176. But Tracy's claims have been difficult to verify: The woman he cites was not sent to a hospital; she was allowed to go home to her parents. Indeed, an investigation into the health situation at the rave yields cloudy results.

Byers, one of the ambulance personnel, tells Salon that no medical people saw any signs of danger regarding the health conditions at the rave. Asked whether anyone at the medical booth had heard reports of overdosing kids at the rave before the cops came in, Byers says, "None that we're aware of -- nothing that anyone reported to us."

In an affidavit filed with a federal court after Fullmer sued Tracy, the medical people at the party appeared to reverse their story. They said that in fact they were concerned that drug use could cause heart attacks among people at the rave. It's unclear why the two stories diverge -- ambulance personnel could not be reached for further questions on the matter.

In any case, other rave experts who were present -- including Jonathan Meader, the Salt Lake City coordinator for DanceSafe, a national organization that promotes healthy conditions at dance parties -- say Versus II was well-managed. Meader says he'd rank it as being "one of the higher-caliber parties" in terms of safe conditions for partiers.

Fullmer and other ravers argue that police violently overreacted in shutting down the event. If Tracy had talked to them about his concerns before police busted in, they would have tried to accommodate him, they insist. They say that his reluctance to do so suggests a cultural bias; you can find drugs at virtually any public event, from NASCAR to a Stones concert, but only at a rave do cops think they have carte blanche to storm in with choppers and tear gas.

"My reaction is that this is not justification to close down a concert," says Barnard, Fullmer's attorney. "My guess is that at any large concert of young people's music there is a going being smoking in the bathroom, marijuana exchanging hands in the facility. The mere fact that criminal conduct occurs by an individual patron does not justify shutting down the venue. If people are passing a joint down the row at a Crosby, Stills and Nash concert, that does not justify sending storm troopers in to close the concert."

Now that a federal judge has rejected Barnard's argument, it's not clear what recourse ravers have. Many say they will now feel unsafe at raves -- fearful of the cops. Ravers still plan to organize -- to protest against and to document police misconduct online -- but they worry that the public won't rally behind their case. "I think it's a cultural thing," says Meader of DanceSafe. "The Utah cops are saying, 'Our way of life is right. Yours isn't.'"