So, if I have this straight,
Aspen owns: Alpine Meadows, Bear, June, Mammoth, Snow Summit, Squaw, Aspin Highlands, Aspen, Buttermilk, Snowmass, Steamboat, Winter Park, Stratton, Snowshoe, Blue Mt and Tremblant.
Vail owns: Heavenly, Kirkwood, Northstar, Beaver Creek, Breckenridge, Keystone, Vail, Park City, Stowe and Whistler-Backcomb.
Whew...did I leave anything out? that is pretty amazing. Blue Mt, Tremblant, Steamboat and Stratton are on the Maxx Pass for 2017-18, I would guess they will be gone for 18-19. It will be interesting to see what happens to the multi resort passes going forward.