A Hardin man admitted Wednesday he trafficked methamphetamine on the Crow and Northern Cheyenne reservations.
Geofredo James Littlebird Jr., 26, pleaded guilty in federal court to conspiracy to distribute meth.
Assistant U.S. Attorney Lori Suek said Littlebird admitted to investigators that he had been distributing meth he got from two men, one in Billings and one in Laurel, from December 2007 until May 2009.
Littlebird started out getting ounce quantities then began obtaining quarter-pound amounts, she said.
Littlebird faces a minimum mandatory 10 years to life in prison and a maximum $4 million fine.
Chief U.S. District Judge Richard Cebull set sentencing for Feb. 17.
Littlebird remains in custody.