Fly Fishing and RV Parks - Where in the Southwest?

Thanks to all for the great info. Appear to be many choices.....even here in CA!

For some reason FF to me would/should occur in places like MT, ID, etc....perhaps from watching the movie, "A River Runs Through It."

I guess I think/dream and am looking for places with meandering streams/rivers, lined with trees and brush; and gently casting into these serene waters.