A 34-year-old Whitefish man was sentenced to 18 months in prison for his part in a marijuana growing operation.

Ryan Gifford Blindheim was sentenced Dec. 20 during U.S. District Court proceedings in Missoula.

Blindheim, who pleaded guilty to conspiracy to manufacture marijuana and money laundering, also was ordered to serve four years of supervised release, pay a special assessment of $200 and pay forfeiture of $86,850.

According to a U.S. Department of Justice news release, Blindheim and several other people ran the Black Pearl marijuana growing operation in Olney between October 2010 and March 14, 2011, when the operation was raided.

The raid turned up 488 plants and 70 pounds of bulk marijuana.

The business was one of 26 locations raided in March as part of a medical marijuana crackdown in the state.

U.S. Homeland Security Investigations initially was notified of a potential situation when it was found that Blindheim and Evan James Corum, 35, Whitefish, were making regular cash deposits of between $3,000 and $9,000 to their Whitefish Credit Union accounts, totaling $86,850 in one month.

Blindheim admitted his activities and the source of the money.

Corum previously was sentenced to six months in prison and six months of house arrest after pleading guilty to conspiracy to launder money.

The investigation was a cooperative effort between U.S. Homeland Security Investigations, the Northwest Montana Drug Task Force and the Criminal Investigation Division of the Internal Revenue Service.