A single-vehicle rollover on Highway 83 in Condon killed a 19-year-old Bigfork man.
Authorities tell NBC Montana that the driver drifted off the road and then over-corrected, causing his vehicle to swerve and roll off the road.
The driver was not wearing a seat belt and was ejected from the vehicle.
He was pronounced dead on the scene of the accident.
Montana Highway Patrol says alcohol is not believed to have played a factor in the accident.
The investigation is ongoing and the victim's name has not yet been released.