Raylynn Miller was found alive Monday by a police officer who was out jogging and came across the crash site about a mile west of Thermopolis in northwest Wyoming.
"She was quiet, just sitting there," said Sgt. Mark Nelson, who found Raylynn at 5:40 p.m.
Raylynn remained hospitalized Tuesday for dehydration and possible broken bones. The girl survived 30 hours in the open and temperatures that dropped into the low 30s overnight.
Authorities said Raylynn was saved by her car seat and later may have been released by her dying father, Shye Miller, 22, of Thermopolis. He survived up to 15 hours after the crash, according to Coroner Clark Mortimore.
"If the coroner's correct on how long he was alive, there was some time that he could have crawled out and released her arm restraints, or she could have possibly released them herself, but she was sitting there at the scene," Highway Patrol Lt. Dave Gluyas said Tuesday.
The crash occurred when Miller lost control of his car on a curve on Wyoming Highway 120, possibly around 11 a.m. Sunday, the investigation showed. The car was traveling at about 70 mph, according to trooper Dan Smith.
The car went over an embankment south of the roadway and cart-wheeled, with the front or back end of the vehicle striking the ground four times. It then went off a cement culvert and came to rest about 150 feet from the roadway in a creek bed. The wreck could not be seen from the road.
Smith said broken beer bottles were found near the car and authorities are investigating whether alcohol played a role in the crash. Miller was on probation for an assault conviction and was not supposed to consume alcohol.
Miller had dropped his wife off at the Thermopolis hospital about 10:30 a.m. so she could fill out a job application. She later reported the two missing, but police were unable to find the car.