Huge, Intense, Powder, No Lines, Incredible Views
Other resorts don't seem as good after skiing Big Sky; Hard to get to
This is by far the best terrain that you will find in-bounds in the US. It has lots of intermediate terrain as well as large, intense chutes and trees that will challenge even the best of skiers. At Big Sky you can go as hard as you want. Also, with so much terrain, you will not only have a lot to explore, you will have many lines all to yourself and virtually no lift lines. Plus, the snow stays fresh far longer than it does anywhere else. It is big mountain skiing with all of the conveniences of in-bounds skiing. Big Sky is undoubtedly my favorite ski resort!
The one issue with it is that it is pretty hard to get to; you have to fly to Bozeman (which often times requires a connection), and then drive over an hour and a half up into the mountains. If you are hit with a large enough snowstorm-- very common in that part of Montana-- it is very easy to become stuck on the road. Be very careful when driving up there. I have been in some very hairy conditions and am surprised to not have wrecked. If you do get up there, though, a skiing paradise awaits you!