It happened on Rt. 8 around 5:00 p.m. Friday.
There were two vehicles involved.
57-year old Gail Hulsey of Litchfield was driving a Toyota pickup truck with her 16-year old son Samuel in the passenger seat.
30-year old Heather Ducast of Belgrade was driving an Audi from the opposite direction.
One of the vehicles crossed the center line and collided head on with the other vehicle.
Gail Hulsey was killed in the crash, the other two escaped with minor injuries.
Sheriff Randall Liberty says investigators are still unsure which vehicle crossed the line or why.
An accident reconstruction team will try to figure that out.
Everyone was wearing seat-belts.