You might want to check further on that. Discounts to Ontario parks are for Ontario residents as I read their web page.
" Question: Does Ontario Parks offer any discounts on park fees?
Answer: Ontario Parks offers discounts on day-use and camping fees to Ontario residents aged 65 and over and Ontario residents who possess a CNIB identity card or Ministry of Transportation accessible parking permit. When making a telephone reservation, please advise the call-centre agents of your eligibility for a discount. You will be required to show proof of your eligibility when you arrive at the park. Reduced campground rates apply to Ontario senior citizens and their spouse who may be any age and persons in the same party under the age of 18 who occupy the campsite. Persons aged 18 to 64 inclusive, who are in the same party, or visit and occupy the campsite, are required to pay full rates."
I can find no reference to non-resident fees for disabilities or veterans. A further check would be in order.
Scorp.