Two Missoula men connected to a medical marijuana operation have pleaded guilty to conspiracy to manufacture the drug.

The U.S. attorney's office says 40-year-old Shawn Slattery and 42-year-old Andrew Umhey pleaded guilty Wednesday during a hearing before U.S. Magistrate Judge Jeremiah Lynch.

Both face a mandatory minimum of five years in prison when they are sentenced on Dec. 22.

Prosecutors alleged that from October 2010 to February 2011, Slattery and Umhey operated the Four-Twenty Ranch LLC, where marijuana was produced and stored. In February, law enforcement officers seized 272 marijuana plants and 32.5 pounds of marijuana from the business.

Associated Press