Grand Forks RCMP say the four-door Oldsmobile Alero had been travelling eastbound, along Kettle River Drive near 12th Street, when it suddenly left the road and drove into the river shortly around 1 a.m.
Police say the 24-year-old woman and sole occupant of the single-vehicle incident managed to swim to shore, with a witness guiding her.
Police say the woman sustained relatively minor injuries, but was transported to hospital as a precaution.
“Police are investigating reports that the driver performed an evasive manoeuver to avoid colliding with wildlife,” said RCMP Cpl. Jesse O’Donaghey.
“Although speed has not been ruled out, investigators do believe that alcohol was a factor in this early morning crash.”
Grand Forks RCMP said a diver was needed to extract the fully submerged four-door sedan from the Kettle River.
Witnesses who have not yet spoken to police are asked to contact the Grand Forks RCMP.