State troopers confirm one person has died in the crash near Arlee. One lane opened at 9:05 after being closed around 6:30am Monday morning.
Troopers report one man died in the pickup truck about a mile south of Ravalli.
Troopers say a witness told them the pickup was headed south and then crossed the center line.
Officials say the semi driver reported he swerved left into the southbound lane to avoid the truck, but the truck swerved back and slammed head on into the semi.
Both vehicles were engulfed in flames.
Officials say witnesses reported both vehicles caught fire.
The driver of the truck, identified now only as a Northwest Montana man, died.
Troopers say speed was not an issue, and that both vehicles were likely going the speed limit upon impact.
However, investigators say alcohol may have been involved and the pickup driver was not wearing a seat belt and was ejected from his rig.