.............................Fly Fishing Yellowstone National Park


I am calling this series Yellowstone Journals and Additional Information. It is a collection of a
rambling mixture of experiences on the streams with some notes, tips and additional
information thrown in. Some of this comes from my video tape logs (record of video shot)
and  notes made on my daily note books.

Fly Fishing the Upper Madison - Part 10

Normally, I would be continuing the White Miller articles and writing about the
adults. The reason I am not doing that today is because I am expecting a new
improved adult fly pattern to be available for me to photograph any day now.
When the new "Perfect Fly" White Miller Adult can be shown with the article on
how to fish them, I will continue.

Little Black Short-horned Sedges:
There is another important caddisfly that hatches on the upper Madison River in
the park. It is the Little Black Short-horned Sedge or
Glossosoma montana.
This is small caddisfly, imitated with a hook size 20 fly. For that reason, most
anglers don't pay it much attention. When they hatch, they hatch in huge
quantities. The trout feed on them because it is so easy for them to do so. Their
pupae can hatch mid-stream but most often they try to make it to the banks on
top of the water to hatch. Trout have plenty of time to pick them off with ease.

These little caddisflies are easy to recognize in their larva stage. The reside in  
cases made of tiny rocks and pebbles. The case is shaped similarly to a horse
saddle and are called saddle cases. You can find some rocks not larger than a
basketball that have hundreds of these little saddle cases stuck to them.

Trout eat them when they are emerging during the time they accent to the
surface as a pupa and as they skitter across the surface to make it to the shore.
The female adults deposit their eggs by crawling down into the water. The trout
probably eat a lot of them during the egg laying activity but we think the adult
imitation is more effective when it is used to imitate those that have hatched and
have entered the water as an adult.  

These little caddisflies hatch during the month of July on the upper Madison
River. The hatch doesn't last very long in any one place but may vary at
different places in the river during the month. You will know it when they hatch.
The stream side foliage and rocks in the water and on the banks will be covered
with them. Of course if you find that situation, it means a great many of them
have already hatched so it is best to catch it when it first starts occurring.

We usually add a tiny bit of non-toxic weight a few inches above the pupa
imitation. Fish it using a down and across presentation. Mend the line when the
fly hits the water to help get it down. Allow the fly to swing around directly
downstream of your position and accent to the surface by stopping the rod tip in
about the 2:00 o'clock position. That is usually when the trout will take the fly.
Not all of the pupae emerge on the banks. Some of them fully develop into
adults on the surface of the water.

We usually present the adult imitation up and across. You want to cast in the
same areas of the stream you see this activity occurring but very near banks
and large rocks and boulders that protrude out of the water. This could imitate
both those that have hatched on the water and are trying to get to the banks
and rocks as well as those that have deposited their eggs and returned to the
surface of the water. There is usually so much activity that it is difficult to tell
exactly what is going on with them. There is one thing for certain, the trout will
eat both the pupa imitation and the adult imitations during the hatch. The adult
has a foam body so it floats well even in rough water.

Most often the water is very warm in the Madison River during July. If so, you will
probably only catch smaller trout. In good water years, of which we have only
experienced on two occasions, the larger trout do not migrate to Hebgen Lake
or at least anglers are able to catch some large ones in the summer. They have
proven that many do migrate to Hebgen because they have netted and taken
data on the migrations. Whether or not some remain in the warmer water and
just do not feed remains a question in my mind. Either way, the results isn't
going to be very good if you choose to fish the river when the water is around
seventy degrees or higher. We suggest that you choose another river when this
problem occurs, even though you may be able to catch a few smaller trout.

Copyright 2009 James Marsh
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"Perfect Fly" Little Short-horned Sedge Pupa
"Perfect Fly" Little Short-horned Sedge Adult