Drumheller RCMP is currently on scene of a single vehicle rollover on Highway 576 near Range Road 184.
The collision happened earlier this morning when a pickup truck travelling eastbound lost control and left the road.
Roads were icy at the time of the collision.
There were three males in the vehicle, the driver of the truck was sent to hospital with minor injuries.
One passenger was transported to via Stars to Calgary with serious life-threatening injuries.
The other male passenger was pronounced deceased at the scene.
Drumheller RCMP and RCMP collision analyst remain at the scene and will are expected to be there for another 40 minutes.
Motorist are advised to use caution when approaching the area. The collision remains under investigation.