This is an awesome idea to give skiiers 3 free days each and 33 free days total at the other resorts on the pass with the purchase of a season pass at one of these mountains.
Looks like I might have to buy a Sierra pass now.
I wanted to ski Crested Butte (was hoping Vail would throw it on the epic) and 3 days there would be pricy. A full Sierra season pass will cost the same as 3 days at CB so I'd ski Sierra for free all year basiclly. I dont think Id ski any of the mountains other than Sierra more than 3 times in a year ever too.