Pale Morning Dun May Flies are an early summer may fly that is being seen on most of the rivers in Idaho. The Owyhee River in particular at this writing you can almost set your watch to a late afternoon hatch. I start most hatches that I’m fortunate to stumble upon with the adult dun dropped 18” with the corresponding emerger pattern. From that point on I can make any pattern adjustments or size adjustment. During any may fly hatch the emerger can make the difference between some fish or a lot of fish caught.
As for a caddis hatch, I can’t imagine fishing a caddis hatch without various patterns of caddis merger. The Klinkhammer emerger is a great caddis emerger pattern to use during a caddis hatch because you can easily track your fly and can easily attach another emerger to the bend of the hook.