Police in northern Alberta are investigating a serious collision on the highway south of Grande Prairie Wednesday morning.

RCMP said the serious crash happened about 30 kilometres south of Grande Prairie, on Highway 40, and four vehicles were involved.

Police, firefighters, paramedics and STARS Air Ambulance responded to the crash.

RCMP said the male drivers of two separate pickup trucks involved in the crash were sent to hospital via ground ambulance with serious injuries, and one male driver of a van involved in the crash was pronounced dead on the scene.

According to investigators, initial evidence suggests a head-on collision set off the collision.

Investigators remained on the scene throughout the morning, and the affected section of road was closed as crews worked to clear up the crash.

The road finally reopened late Wednesday afternoon.