I'd call this article flawed in many ways, the biggest of which is- shouldn't the real metric being used Carbon footprint per skier visit?
When I look at that list, the one thing that leaps out at me is that all of these 'mountain towns' are actual communities of year round residents who work and live there 12 months of the year (for the most part). That is a GOOD thing. The carbon footprint of a place like Vail, where skiers fly in to Denver, rent a car and drive to Vail, ski for a few days then repeat the process to go home... that's much, much worse. Isn't it?
In Vermont, places like Killington and Okemo have much higher numbers of skier visits per season than Stowe does... but no one actually lives in either place. Shouldn't that make their carbon footprint worse than Stowe, where there is an actual vibrant town of year round residents?