The Wyoming Highway Patrol says a 29-year-old Colorado woman is dead after rolling her commercial vehicle 15 miles east of Shoshoni on U.S. Highway 20/26 early Wednesday morning.

Cheryl Rapue of Wiggins, Colo., was driving westbound when her vehicle left the roadway and rolled at around 4 a.m. Wednesday. Rapue was carrying mail for the U.S. Postal Service from Douglas to the Big Horn Basin.

Rapue was ejected from the vehicle and later died at the scene. Authorities say it is not known whether she was wearing a seat belt.

Troopers believe fatigue may have been a contributing factor in the crash. After troopers completed their investigation, USPS employees were called to the scene to retrieve the cargo.