Glacier National and Banff

We've taken two separate trips to Glacier and one trip to Banff, Lake Louise, taking both trips past Labor Day. We had a TT at that time and stayed at Glacier once at Mountain Meadows RV park on the Hungry Horse side, then another time we stayed at the Glacier KOA moving to the St. Mary's KOA on the North side. All three will easily work for you Class A. When we went to Canada, we thought we would easily find a place with hookups at Banff w/o reservation. We were hoping to stay at Tunnel Mtn, but when it was full, a local directed us to Two Jack Main, which may work, may not. Here's a link to some pictures of where we stayed - Banff and Lake Louise camping- Lake Louise has a nice campground and we had no problem getting in by arriving early in the day. Your rig would easily fit there. I know you didn't ask about Lake Louise but it's fairly close and may be worth your visiting.

The link I provided has additional RV information for that part of Canada for you.