The Provencal Park in Jasper is great. You will have Elk in the campsite and Bear wandering around town in the evening. Considering the time of year I would start there and come down the Ice Fields Highway to Banff. While in Jasper make sure you go out to Maligne Lake.
The saying is which ever one you visit first, between Banff and Jasper, the first will always be your favorite so you now know which is my favorite.
WBCCI 12156 AIR 3144 WACHUNG TAC NJ6
2004 Excursion 4x4
1991 34 ft. Excella +220,000 miles, new laminated flooring, new upholstery, new 3200 lbs axles