Wellington County OPP are investigating an all-terrain vehicle crash near Mount Forest.
Emergency crews were called to an area on Sideroad 2 East on Saturday at around 11:45 p.m.
They located a single ATV and the operator.
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Investigators say the 33-year-old resident of Wellington North Township was taken to a trauma centre by air ambulance with serious injuries.
They say they are trying to determine what caused the crash.
Anyone with information can contact Wellington County OPP at 1-888-310-1122.