Copyright 2014 James Marsh
Hatches and Trout Flies for the Middle River- Yellowstone National
The hatches on the Middle River are quite prolific for such a small stream. We have even
found a few Green Drakes there. The few meadow sections of the stream have some aquatic
insects that are not present in the fast water sections of the stream.

The PMDs, or Pale Morning Duns, rank the number one hatch. They start about the first week
in July and last all the way through August. Blue-winged Olives are usually hatching when the
season opens but this stream it's still far too early to fish this stream. They start hatching again
about the first of September. Green Drakes were present during the middle of July. We would
think these hatch for only about two weeks at the most in the short river.

Spotted Sedges are very plentiful, especially in the moderate water sections. They start
hatching around the first part of July and last through August. Little Sister Caddisflies hatch
during the same time period. Green Sedges are very plentiful in the fast water sections. The
larvae of these caddisflies are called Green Rock Worms and they are very plentiful in some
sections of the stream. They hatch from about the middle of July to near the first of October.  
Little Short-Horned Sedges hatch during the second part of July.

Golden Stoneflies start hatching about the first or second week of July. They will be present in
the fast water sections of the stream. Yellow Sallies, or Little Yellow Stoneflies, are also
present. They start hatching the later part of July and last until the first of September.

You will find Yellow Quills, or the
Eperous species, hatching from about the end of July through
August. Western March Browns start hatching about the same time and last through August.
Both of these mayflies prefer the faster sections of the stream such as the riffles and runs.

Grasshoppers, ants and beetles are very plentiful in the few meadow sections of the Middle
River. Imitations of these insect will work during late July, August, September.

You may consider taking some streamers if you fish this stream in the Fall. Brown trout move
out of the North Fork and into the lower end of the Middle River during the spawn.

Our "Perfect Flies" have been tested on the Middle River several times. They have proven to
be more effective than any of the generic or attractor flies, even on the cutthroat and brook
trout. We have specific imitations of everything that hatches in Yellowstone National Park and
in all stages of life that the trout eat them in. If you haven't already tried them, we certainly
hope you will.
Middle River, YNP
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