CHEYENNE - A Canadian truck driver who went missing for more than a week was found dead inside his rig at a rest stop along Interstate 80 in southern Wyoming.

The Wyoming Highway Patrol said Tuesday it is believed that 69-year-old Clark Sutherland of Langley, British Columbia, died of natural causes.

Sutherland was reported missing by his trucking company on June 3. Road Rider Transport told law enforcement officials that Sutherland last made contact with his wife via cell phone on May 30, according to the patrol.

The trucking company notified the patrol that when Sutherland made the cell phone call, he was eastbound from the Wamsutter area. Troopers in the Cheyenne and Laramie areas were notified to watch for Sutherland's eastbound rig.

Sutherland was delivering a load from Canada to Pueblo, Colo. His truck tractor unit was not equipped with a GPS locating device. It was unknown as to exactly which route Sutherland might have taken to Colorado from Wyoming, and it was unknown if he was in fact still within Wyoming, the patrol said.

On Friday the agency received a teletype from the Royal Canadian Mounted Police indicating that Sutherland had been reported by family members as a missing person. Neither he nor his truck had arrived at the final destination in Pueblo.

On Monday, a Wal-Mart truck driver notified the Wal-Mart Distribution Center in Bentonville, Ark., that he was parked beside a 2000 Freightliner truck that matched the description of Sutherland's missing truck tractor combination, the patrol said. They were at the Wagon Hound rest area about 42 miles west of Laramie.

Troopers responded to the scene and located Sutherland's body in the cab of his truck. Foul play is not suspected, the patrol said.