A 30 year old Story man was killed Sunday in a one-vehicle rollover crash on Interstate 90 six miles east of Sheridan.

Wyoming HIghway Patrol Spokesman Sgt. Steve Townsend says David Wallace was eastbound on I-90 when his 2003 Ford Pickup drifted off the right side of the roadway and hit a guardrail. Wallace then over-corrected, steering to the left, causing the pickup to spin counter-clockwise across both lanes. Townsend says the pickup then vaulted over the guardrail on the left side of the highway, rolling 1 1/2 times down a steep embankment in the median. Townsend says Wallace, who was not wearing a seat belt, was ejected from the cab of the pickup.

Because the crashed vehicle was not visible from the roadway, Townsend says it was not discovered for some time after the accident. As a result, the exact time of the fatal crash is unknown,l according to investigators.