Huron County OPP says a 32-year-old Walkerton woman was airlifted to hospital from the scene of a collision near Clifford.
Hwy. 9 has reopened after the head-on crash at about 10am Wednesday morning left three people injured.
The Walkerton woman who was driving a Ford Focus sustained serious but non-life threatening injuries.
"The preliminary investigation has determined the driver of a Ford Focus was travelling north on Hwy. 9 when she spun out of control into the path of a southbound Cadillac SRX resulting in a head-on crash," police say.
A 66-year-old Cadillac driver and his 64-year-old female passenger, both from Mildmay, were treated for minor injuries.
Huron County Ontario Provincial Police continues to investigate.