A collision between a minivan and a tractor trailer just west of the Wyoming-South Dakota border in Niobrara County resulted in the death of a Cheyenne man on Tuesday.

The Wyoming Highway Patrol says 19-year-old Graham Parfitt was driving his 2004 Kia Sedona eastbound on U.S. Highway 18 at around 8:00 a.m. Tuesday when swerved into oncoming traffic and struck the westbound tractor trailer of 49-year-old Michael Krzes of Milaca, Minn.

Troopers, upon arrival, found both vehicles in the eastbound ditch.

Parfitt was found dead at the scene. Krzes was taken to Niobrara Health and Life Hospital in Lusk for treatment.

Sgt. Stephen Townsend says U.S. 18 was clear and dry Tuesday morning.

Townsend says troopers are investigating whether medical complications or driver fatigue contributed to the accident.