The Canyons - three runs I guarantee will be great for upper intermediates-
All three are steep blues with either great views or interesting terrain, or both.
Also, at Deer Valley - Empire area has a run called Supreme that is a great way to ski around the tougher terrain and decide if you want to take the plunge or not. The run is fun in itself, and it goes past Lady Morgan bowl, which is a fairly easy black. I would also recommend Bald Mountain for upper intermediates, particularly a really long blue called Tycoon near the Sultan lift. For a step up at Deer Valley, Stein's Way and Perserverance can be tougher long mogul runs - Tycoon is mostly a cruiser with maybe some moguls scattered about.
At Park City Mountain- there are some nice blue -black runs off of the McConky's and Pioneer lifts. Its a separate little valley with a lodge near the lifts so you can hang out in that area before or after lunch. Particulary, Tycoon (yes, same name as Deer Valley), and Hawkeye. Also, off of the ridge of King Con, there's a new lift called Silver----? (not Silverlode- that's a different one) and a twisty long double blue called, I think First Deception that has moguls and probably should be rated as a black. I also liked Silver King and Crescent, which are blacks, but not too tough or long.