SpriteMcBain,
Here is the link for general provisions for provinicial parks (
https://www.ontario.ca/laws/regulation/070347#BK38), Section 35 reads:
35. No person shall use or display a firearm in a provincial park other than,
(a) a peace officer in the lawful execution of his or her duties;
(b) an employee in the Ministry or an agent of the Ministry for the purpose of wildlife management and control;
(c) a person lawfully hunting under the authority of subsection 9 (3) of the Fish and Wildlife Conservation Act, 1997;
(d) a person authorized by the superintendent to use or display a firearm in a provincial park. O. Reg. 347/07, s. 35.
So you can't use or display a firearm in a PP unless it is for the purposes of hunting within the FWCA. You can bring it to a PP but it has to stay out of sight unless you are hunting.
Dyth