BILLINGS, Mont. (AP) — A 29-year-old Colstrip man has admitted to driving drunk at the time of a crash near Ashland that killed his passenger.

The U.S. Attorney's Office says Kyle Lee Fulmer pleaded guilty to involuntary manslaughter Tuesday during a hearing before U.S. District Judge Sam Haddon. Sentencing is set for Sept. 11.

Prosecutors say Fulmer's blood-alcohol level was 0.137 early on Sept. 19, 2012, when his pickup truck went off the road, through a barbed wire fence, rolled down an embankment and landed upright in a field on the Northern Cheyenne Indian Reservation

The day after the crash, Rosebud County Sheriff Randy Allies told The Billings Gazette that 25-year-old Crystal Marie Parker RedRobe was killed in a Sept. 19 rollover crash 13 miles south of Ashland.