The Montana Highway Patrol says a drunken driver is to blame for a crash on U.S. Highway 314 near Decker that caused a semi to spill 38 tons of coal.

Trooper Ben Panas tells The Billings Gazette the driver of a car tried to pass a semi hauling two trailers of coal as it traveled around a curve in the highway at about 6 p.m. Wednesday. The car hit a guardrail. Panas says it's not clear if the semi hit the car or if the driver crashed because he was trying to avoid the car.

Panas says the driver of the car will be charged as soon as officials verify who was driving.

The driver of the semi and three people in the car were treated at a hospital in Sheridan, Wyo.