Wood Buffalo National Park Canada's largest national park, and UNESCO world heritage site is on the Alberta Northwest Territories border does not charge anything to enter the park, no pass is required.
Kluane National Park also does not charge a daily park fee as no pass is required either :
Sep 2015 - Kluane Nat'l Park Yukon Territory -Kathleen Lake-
Aug 2008 - Wood Buffalo Nat'l Park Northwest Territories
The only other National Parks in Canada I have visited are the Rocky Mountain four of Banff, Jasper, Kootenay, and Yoho in September 2011, 2012, and 2013.....was planning to visit Parks Canada again in 2014, 2015, 2016 and 2017 however either a health issue or mechanical issue would happen leading to lack of time constraint issue with only a yearly 3 week vacation timeframe allowed since I am still a working stiff with a long distance to cover upon a round trip...Last four years was either a turnaround or a plan B route somewhere else for me - but hey, at least I still made it to western Canada on a yearly basis since 2006 in my camper.
After 21 years of camper hauling with my 70 Ford Truck, it was forced to retire starting in 2017 as it is now an all purpose truck for the first time that I owned it...Took two of my three weeks of vacation time working on converting and upgrading my now current designated camper rig in 2017 as I did get to spend 6 days in Canada which was better than nothing in that regard, although I did not get to utilize my 2017 Parks Canada pass like I had planned to.
As noted by others, Parks Canada does not restrict senior passes to Canadian citizens.
1975 Ford F250 2WD Ranger XLT (Owned June 2013)
460 V8- C6 Trans- 3.73:1 (196K Total Mi)
2000 Fleetwood Angler 8ft Cabover
Air Lift 1000 (Front)
Hellwig 3500 lb Helper Springs (rear)
Hellwig Front and Rear Sway Bars
Goodyear G971 LT Series (siped)