UPDATE 01/20/17: The OPP have said that the girls have been found (see Tweet below).
UPDATE 8am: Another girl from Orillia has been reported missing. Her name is Brianna Martin and she was last seen with Savannah Simcoe and an unkown man. Details below.
Original Post, 6:46am:
MISSING: 17-year-old Savannah Simcoe. She was last seen near the LCBO on Mississaga St, in Orillia.
Anyone with information is asked to contact the OPP.