The woman lost control of her vehicle at 9 p.m. Saturday on westbound Interstate 84 near Milepost 103 east of Mountain Home.
The vehicle entered the median, rolled five times and traveled 187 feet before landing on its top. The woman, who has not yet been identified publicly, died at the scene. She suffered severe head injuries and was trapped in the vehicle, according to the Elmore County Sheriff’s Office.
Passing motorists, including an off-duty emergency medical technician and an Idaho National Guard soldier, stopped and tried to help the woman before emergency responders arrived. The sheriff’s office, Elmore Ambulance Service and the Mountain Home Fire Department responded.
The cause of the crash, which happened as the woman was driving from Twin Falls to Boise, remains under investigation. Drugs or alcohol are not believed to be a factor, the sheriff’s office said.