Not yet. I was going to fish Henry's Fork (I know it's the Snake)this past summer since a former colleague has a drift boat and lives within 30 minutes. I even bought a 4 weight fiberglass rod in hopes of failing miserably at dry fly fishing. Sadly I haven't spent much time exploring the western states except for the Provo and Weber in Utah and some smaller streams in Estes Park.
It's amazing how different fly fishing is in the lower 48 compared to Alaska. I couldn't tell you the first thing about matching the hatch as bug hatches, do happen up here, but they aren't widespread.
@huskermack would know more than me since he likes to fish for grayling on a freestone river. Where I live people don't bother with bugs since most of the fish are centered around salmon. People fish egg patterns similar to nymphs, flesh flies to imitate dying salmon, or a variety of rabbit fur streamers.