The rainbows that fin their days away in the deep green pools of the Castle River think they can fly. When hooked they nearly always reward the fly angler with an aerial display that that leaves you praying the hook will hold. The takes are always solid and the fish is usually airborne before the angler realizes what’s happened. The Castle also holds Cutthroat trout which are quite eager to take the fly. This is one river where you can still find success while using attractor type fly patterns. Hopper fishing on a warm breezy day in August or September on the Castle can often be quite productive.