A 37-year-old Airdrie, Alta., man missing since early October has been found dead in Montana.

The Yellowstone County Sheriff's Office said the body of Cameron Collin was found about 9:30 a.m. Saturday in a creek south of Billings.

Collin had been in Montana for a wedding when he disappeared sometime on the night of Oct. 4.

Collin's sister said the family is grieving.

"We got the news from the sheriff today," Julia Collin told CBC News.

"My family is deeply saddened and at a loss."

Private investigator Mike Toth was hired by the family, and told the Calgary Eyeopener Collin had wandered off from the party on a property about 18 kilometres outside of Billings.

"At one point late in the night, Cam was pretty intoxicated, so the rest of the bachelor party left him alone in the barn and said they were going to go into town," Toth said Thursday.

"The last they saw him, he was sleeping in a chair. When they came back, about an hour and a half later, he was gone. His suitcase and jacket were still laying there, but Cam was nowhere to be found."

A sheriff's office press release issued Saturday said there has been no indication of foul play during its ongoing investigation.

An autopsy will be done Monday to determine the cause of death.

With files from The Associated Press, the Calgary Eyeopener and CBC's Anis Heydari