A Colfax County sheriff’s deputy spotted the crash around 2:15 a.m. on a county road just east of an exit to Richland.
The deputy says a man and a woman were thrown from the sport utility vehicle and taken by ambulance to a Columbus hospital, where the woman was pronounced dead.
Officials say the man’s injuries are serious, but that he is expected to live.
Authorities have not yet released the names of the man or woman pending notification of family members.
Authorities have not determined who was driving, but are investigating. Investigators say neither was wearing a seat belt at the time of the crash.