PMD Nymph

On western freestone and tailwater riffles through the Pale Morning Dun hatch window in summer, fished dead-drift ahead of the rising duns before switching up to the emerger.

Its slim olive-brown crawler profile and modest weighting match the naturals as they turn restless and drift more heavily in the hour or two before the hatch actually breaks, so it's already reading as food to fish keyed on nymphs before a single dun has shown.