Hancock County sheriff's deputies said they got a call around 1:46 a.m. about a single-vehicle crash on Route 9 in Township 28.
Their investigation revealed the vehicle was heading east when the driver drifted onto the shoulder.
The driver overcorrected, which caused the vehicle to go into a skid before going off the road and rolling over.
Tonya Leach, 37, was killed in the crash and Merrill Muncey, 32, of Pembroke was taken to the hospital with injuries that were not considered life threatening.
The crash remains under investigation.