Pale Evening Duns
.............................Fly Fishing Yellowstone National Park
08/11/08

Pale Evening Duns:

Pale Evening Duns can be an important mayfly to imitate on some of the streams in
Yellowstone National Park. It is not a huge hatch but on the streams where it does exist
it is important because if hatches at a time there are few other mayflies hatching. Most
of the stonefly hatches have occurred and there may not even be many caddsflies on
the water.
The Pale Evening Dun is in the
Heptagenia group of mayflies. The Heptagenia solitaria
species that exist in the West is usually called the Gray Fox. The other species, mainly  
the
elegantulata species, are usually called Pale Evening Duns. Although they almost
never hatch in prolific quantities, they may be found in just about all of the streams at
all elevations. We know they are found in the Yellowstone, Lewis and Gardner Rivers
but we have not checked specifically for the mayflies in other stream samples we have
taken.

Pale Evening Dun Nymphs:
Heptagenia nymphs are clingers. They look much like the other clinger nymphs except
they are generally much darker. They have three tails. For the most part, they are
found in streams with faster moving water. They prefer pocket water with lots of runs
and riffles.
We are not sure if it would do much good to fish an imitation of this nymph anytime
other than just before they are about to hatch. Clinger nymphs stay hidden beneath
and down between the small rocks and cobble on the stream's bottom most of the time.

Presentation:
The standard non-toxic weighted nymph and indicator method works well for the nymph
imitation. Up or up and across presentations work best in the type of water these
mayflies are found in.

Coming Up Next:
Pale Evening Duin Emergers

Copyright 2008 James Marsh