MECOSTA COUNTY, MI -- Police from seven agencies who responded to a "rave"-style party that attracted thousands Saturday night chose to manage the situation from the perimeter, rather than moving in to hand out potentially hundreds of citations.

Multiple 911 calls began to come in around 1:20 a.m. Sunday, Aug. 3 about partygoers who had overdosed on hard drugs at 4708 70th Ave., in Mecosta County's Hinton Township. The location is southeast of Canadian Lakes.

Police and paramedics arrived to find Five Mile Road almost entirely blocked by vehicles near the party location.

Dispatchers labeled the party a "mass casualty incident" response, which meant they were calling in every available deputy, officer, trooper and paramedic from Mecosta and neighboring Montcalm and and Isabella counties.

But even with the large police response, the party was far more than what police could have handled from the inside, Mecosta County Sheriff Todd Purcell said.

At least 2,000 people are believed to have attended.

"We were so outnumbered," Purcell said.

Despite the hard drug use and underage drinking going on — authorities believe the majority of attendees were under the age of 21 — police did not attempt to break things up or go in to hand out citations.

They chose instead to manage the scene by allowing the party to continue for several more hours, with multiple police agencies standing by. It was that or risk hundreds of intoxicated drivers fleeing and taking to area roadways.The majority of those drivers were people that do not live in Mecosta County. They did not know the rural roads well, Purcell said.

Another concern was potential injury to responding police and paramedics.

"We had information they were not in a cop-friendly attitude," Purcell said of those gathered.

Police remained on scene until about 7:30 a.m. Sunday

The sheriff had no record of traffic incidents in Mecosta County directly related to the party, but Michigan State Police troopers handled a crash involving a car that veered into a Mecosta home. Those inside the vehicle reportedly told authorities they had come from the 70th Avenue address.

The party's size proved to be a challenge that in Purcell's memory, rivaled only a riot in the mid-90s at Ferris State University in Big Rapids.

Many teens took to social media in hours after the rave, tweeting photos with a "Project P" Twitter hashtag — modeled after the 2012 movie, "Project X," about a large West Coast party.

The gathering, from all accounts on social media, was planned with the goal of attracting as many people as possible. An open invite on Twitter attracted visitors from miles around.

But things quickly got out of hand. Authorities said it's important for teens to realize how easily this can happen as the number of attendees grows. Mixed with drugs and alcohol, it's a recipe for serious trouble.

"You have to be aware of the ... safety concerns and issues that could happen," Purcell said.

Five or six people were hospitalized for drug overdoses or other injuries suffered at the party. Among those was a man who jumped off the roof of the home and suffered a serious neck injury, Purcell said.

Another 19-year-old woman was dropped off at a police staging area after reports of a sexual assault. Police continue to investigate what happened to her.

A report has been forwarded to the Mecosta County Prosecutor's Office for review and potential charges against the host.