Highway 11 is shut down in the Orillia area after multiple crashes on the snow-covered highway.
The Orillia OPP say the southbound lanes between Coldwater Road and Line 15 are closed due to a collision. Firefighters and paramedics have also been dispatched.
There are reports on social media that up to 50 vehicles may be involved and that there are multiple crashes that have occurred along that stretch of highway.
An intense snow squall has been hovering over Orillia for a few hours, creating whiteout conditions.
Police are asking people to avoid any unnecessary travel.
The highway is expected to be closed for some time.