Mariposa is good, but it's not as good as some reviews would have you believe. However, since it's the only highend restaurant in Deer Valley, you either love it or get in you car and drive down the mountain to Park City.
Basically, there are no surprises on the menu. You've had this food at other restaurants before. Service is a little stuck up, but that's probably because they just waited on a celebrity before you arrived.
Oh well. When you've been skiing all day it's hard to complain.
Pros: Fire Place, Close to resort