Pale Morning Duns
.............................Fly Fishing Yellowstone National Park

PMDs or Pale Morning Duns emerge, as their name implies, in the morning from 9 am to
11am as a general rule. Like many other mayfly hatches the activity usually last only a
short time, an hour or so, although it may go much longer on during cloudy, overcast
The PMD nymphs swim to just beneath the surface of the water and shed their nymphal
casing. It is during this time that the nymphs are suspended the trout has the best
opportunity to feed on the emerging duns. PMDs commonly have a large proportion of
cripples and trout are well aware of it, feeding on them with ease.

Flies fished just under the surface of the water imitating the emerger are usually
effective during a hatch. You can begin by dead drifting a floating nymph or soft hackle
emerger pattern just under the surface.
Normally PMD nymphs migrate to hatch in calmer, slower moving water that is near their
normal moderate to fast water habitat. A long leader and tippet of 6x or even 7x will get
far more results that something shorter and heavier. This type of water can require a
down stream or cross-stream presentation that is made to an individual rising fish. Be
sure to get the fly beneath the surface film before it gets to the fish.
We don't suggest that you stick with the emerger patterns very long after the hatch
begins. They are very effective flies but you can catch plenty of trout on dun patterns or
the dry fly which most anglers prefer.

Coming Up Next:
Pale Morning Duns - Duns

Copyright 2008 James