Twelve miles from Aspen and included on the same lift pass, Snowmass is also a resort in its own right. It isn't as well known as its glitzy neighbour, but Snowmass offers fantastic skiing and accommodation, at slightly more affordable prices. Lots of the accommodation is also ski-to-your-door. The joint lift pass is rather pricey but is does allow access to the biggest vertical in the US (1342m). The skiing is more balanced than at Aspen, since most standards have a variety of choice at Snowmass. It doesn't have the advanced challenges of Aspen Mountain, but welcomes boarders with open arms. The recently extended Cirque also has some great powder terrain. It offers the best intermediate skiing on the pass, in addition to decent slopes for beginners. Snowmass provides excellent ski tuition and childcare, so families and learners are extremely well served.
Overall, Snowmass is a resort of convenience rather than charm. It has just about everything you may need, but doesn't offer a great deal of après-ski. There is access to cross-country skiing in Roaring Fork Valley. Other non-skiing activities are available, but if you really want to get to grips with this area you may wish to try Aspen.