Authorities in Hancock County raided a pair of parties on St. Patrick’s Day, charging nearly 50 people with alcohol offenses and shining a light on what Sheriff William Clark called an ongoing problem of underage drinking.

Seven adults were arrested and charged with furnishing a place for minors to consume liquor and another 40 partygoers under the age of 21 were issued summonses for possession of liquor by a minor.

“I’ve been doing this for 35 years and I can’t think of a time when we’ve had more than 50 offenses in one night,” Clark said Monday.

Officials first responded to a party on Beech Hill Pond in the northeastern Hancock County town of Otis at about 9:30 p.m. Friday.

Clark said his department received credible information about the party from several sources and added that the get-together had been advertised on personal Web sites.

When police arrived at the seasonal home Friday, several partygoers scattered, but about 60 were detained, the sheriff said, and were separated into categories by age.

Dustin Dunn, 19, of Bar Harbor, was arrested and charged with furnishing a place for minors to consume liquor. The home belonged to Dunn’s parents, but the teenager did not have permission to be there, Clark said.

In addition to Dunn, 28 partygoers in Otis were issued summonses for underage drinking.

As Hancock County Sheriff deputies sorted out the party in Otis and started writing summonses, officials received word that another large party had broken out in Castine, several miles away.

Clark said another 50 or so people, including many more underage drinkers, had gathered at a large mansion near Maine Maritime Academy when police arrived shortly after midnight.

The mansion was being rented by 10 young men, but only six were present at the party late Friday. Each was charged with furnishing a place for minors to consume alcohol and another dozen or so visitors under the age of 21 were issued summonses for underage drinking, Clark said.

The six arrested in Castine and charged with furnishing were: Jeffrey Angleberger, 21, Daniel Rosen, 24, Evan Seavey, 21, Timothy Boucher, 22, Chris Metcalf, 22, and Matthew Zeh, 22.

Zeh also was charged with assaulting a police officer.

As if the parties weren’t enough, while officers were driving from Otis to Castine, they also pulled over and charged two people with operating under the influence.

Clark said he hopes the two raids serve as a reminder that officials are on the lookout for underage drinkers.

Hancock County recently received $7,500 in state funding for its underage drinking enforcement task force, a multi-jurisdictional group of about 12 officers.

“We’ve been waiting for this type of information and we hope this is a wake-up call to this age group,” Clark said. “This definitely will promote an ongoing discussion.”

The sheriff added that he was thankful the parties didn’t feature more serious problems such as sexual assaults, illicit drug use or worse.

“All it would have taken is one guy to go out on the ice [on Beech Hill Pond] and fall through,” he said.