The Sheep Creek is an awesome Alpine lake pattern that is known to imitate a snail and possibly damsel nymphs. But in reality, the window of opportunity for trout to feed in most Alpine lakes is very narrow. The season comes late and ends early, so the fish in these bodies of water are eager to cooperate. Having said that, this pattern also fishes very well nymphed in rivers with stoneflies and caddis.
The Ground Stone Sheep Creek was tied for a golden stone nymph variation. This fly has fished just as well as some of the more well-known golden stone patterns. You really should have a few in your box. Sometimes it just takes a little variation of a pattern to change your luck!