Rockies. Dollar goes further the closer you stay to Denver since several already live there and can/could drive.
Flight areas that have been thrown out are Jackson Hole and the SLC area resorts.
Your timing is real rough as both the Ikon and Epic multi-day passes, where you by far save the most money, just became unavailable for the year. If you are wanting to ski a bigger resort, what this means is that you are at the mercy of buying day or multi-day passes for each individual resort for very high prices, likely $150+/day, unless you can snag some Epic buddy passes off of somebody. Even those are pricey though. However, if you are good skiing some smaller resorts in Colorado, which still can be good and fun, I believe you can still buy a Gems card for like $42.
Gems Discount Card - Colorado Ski Country
Want to ski more for less? Of course you do! Cash in on a goldmine of Colorado skiing and riding with the Gems Discount Card.
www.coloradoski.com
Once you buy the card and it gets mailed to you, it gets you either buy one get one free or 30% off a single lift ticket at a bunch of smaller resorts like A-Basin, Monarch, Ski Cooper, Eldora, Loveland, Powderhorn, Grandby Ranch, Echo and Sunlight. I think you can use the discount twice at each per card. My favorite resort on that list is by far A-Basin, which has some excellent terrain, especially if you are a good skier. The crowds are low and the vibe is as good as it gets there too. I've done a really fun trip before where we skied both A-Basin and Loveland, which made for a great affordable trip. Just be prepared that both are very high altitude and with a lot of their terrain above treelines, it can get quite cold. However, both give you the feel of skiing on the top of the world, which they pretty much both are. At Loveland, you are literally skiing the Continental Divide. If you go on weekdays, you can also get by staying on the edge of Denver for cheap and driving up for the day beings how they are two of the closest resorts to Denver. The biggest downfall of both resorts is A-Basin has one speed lift and Loveland has zero.
In future years, I recommend planning further ahead and buying multi-day either Epic or Ikon passes where prices are SIGNIFICANTLY cheaper to the tune of something like $80-$130/day. It really is the only way to go anymore. The major resorts are all trying to push everyone this direction and they are doing it with pricing.