This morning's crash site. Photo provided.

UPDATE: Fremont County Ambulance’s Todd Smith said the responding ambulance took 33 minutes to make a 50 mile trip to the scene, not the hour and a half reported by Jimmie Bryan. According to Smith’s records, the ambulance was dispatched at 4:18:31 a.m. and arrived at 4:51:21 a.m.

(Moneta, Wyo.) – The Wyoming Highway Patrol is investigating driver fatigue as the possible cause of this morning’s fatal crash east of Shoshoni. WHP Lt. Tom Adams said Cheryl Rapue, 29, of Wiggins, Colo., was the driver of the westbound United States Postal Service contracted mail truck.

Rapue’s truck reportedly went off the right side of Highway 20/26 for unknown reasons at about 4 a.m.. Adams said the investigation showed she over-corrected to the left, causing the truck to go off the road and rolling one and one-quarter times. She was ejected from the vehicle; seatbelt usage is unknown at this time.

While driver fatigue is a possible cause of the crash, Adams said no one will never know exactly what happened. Rapue was the only occupant.

Adams said Rapue was transported to SageWest – Riverton and passed away there shortly after 8 a.m.

USPS Communication Office spokesperson David Rupert in Denver confirmed that is was “one of our over-the-road contract drivers on the Casper to Shoshoni route.” He said all of the mail at the scene had been recovered. The truck was en route to Worland.

A man named Jimmie Bryan has commented on Oil City, saying he was the first to find her. He said help did not arrive on scene for an hour and a half. Adams was unable to confirm when the first responders got to the scene.

Read the initial report on the crash here.