Tiny Baetis mayflies are perhaps the most commonly encountered and imitated by anglers on all American trout streams due to their great abundance, widespread distribution, and trout-friendly emergence habits.
That's an amazing scene. I always love fly fishing works that picture the angler in their cast just before the 'moment of truth'. It gives a feeling of suspense to the work.
At least for me, anyway...
That looks amazing, Mark!