I have to put in a word for the Canmore (Alberta) Heritage Day Folk Festival. It's held in a gorgeous setting in the middle of the Rockies (mountains in every direction). Although it's small enough that it hasn't lost the local favour, it gets big names by virtue of being close in time to the Cagary and Edmonton festivals, so it's a stop on the Western Canada tour. (I shouldn't tell people -- now everybody will go there, and it'll get big and unmanageable...)