Fly fishing Utah

I know Utah has excellent fly fishing, but I’ve never gone and need some help finding good water.

So my friend and I are gonna take a trip to Utah from Colorado to watch some hockey (Utah HC) and he wants to ski. The areas he wants to ski are Alta and Snowbasin. Is there any good water near these areas? Will it be frozen? Am I outta luck if that’s where he wants to ski? Any recommendations, tips, good areas, etc would be greatly appreciated