A 55-year-old Centerville man had just gotten off work and was going home, driving east on 1800 South when he struck Peterson while she was in the middle of the road.
The first deputy who arrived saw that she had suffered a massive head injury and performed CPR. Peterson was taken to a hospital, where she was later pronounced dead.
The driver of the vehicle was "really shaken up," said Weber County Sheriff's Sgt. Lane Findlay. He was evaluated at the hospital for possible shock and anxiety. His name was not immediately released.
Deputies said that the accident is under investigation, but they do not suspect the driver committed any traffic violations or was driving impaired. The driver voluntarily submitted to a routine blood draw to determine his blood-alcohol level.
That stretch of road is fairly dark, Findlay said, describing the incident as seemingly a "freak accident."
The horses, which were not harmed, were eventually rounded up by a neighbor. Findlay was not sure how long the animals had been out of their pasture or if they had escaped before.
"Usually it's the animals that get hit… It's so rare that it's the owner," Findlay said.