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

10/10/09

Catching Yellowstone Cold Water Trout - Part 18
continued from Part 17

Yesterday, I injected the Yellowstone articles on the Blue-winged Olives
Spinners but didn't finish everything I wanted to convey. They can be an
important part of the hatch during the cold months of the year because they fall
spent earlier during the day than they normally do. I would say the
baetis, or full
hook size 18, BWO spinners would normally start falling in the afternoons about
the time the hatch for the current day has ended. About the only consistent
thing that we have noticed is that they do not fall during the coldest parts of the
day, meaning early or very late in the day. I have found spinners on the water at
the same time the duns were hatching. When I say "found" keep in mind that
you are not normally going to be able to spot the spinners on the surface with
the naked eye. You would also have a very difficult time seeing any trout eat
them from the surface because they just sip them in without making a splashy
rise. They are very difficult to see, especially if the sky is overcast and the light
is low. I find them using a small skim net that fits over my landing net. By just
placing it in the water and holding in one position half in and half out of the
water, you will collect anything floating downstream on the surface.

Many of the male insects do not fall in the water. This is especially true if the
wind is blowing very much. That fact, plus the fact that the hatches are not very
prolific during the cold months, account for the normal sparse numbers of
spinners. The size of the hatch and spinner falls can be deceptive. My guess is
that it doesn't take a lot of insects falling in the water in cold water for the trout
to notice them. At least there is not much of anything else in the way of hatches
with the exception of midges.

The other problem is the fact the BWOs deposit their eggs by touching their
abdomens on the surface, crawling down rocks and boulders and diving to the
bottom. You don't know whether or not to fish a dry spinner pattern, or wet fly.
My suggestion is that if you know there is a hatch of them occurring and you
have fished the nymph and emerger imitations without success (or maybe you
were successful and the hatch ended), try the dry and wet spinner patterns.  

The spinners fall in the same water they hatch in but will collect at the end of the
current seams in the slow water. Fish the wet spinner pattern in the current
seams and the dry fly spinner at the end of the current seams in the slow water.
Our success with spinner falls of BWOs during cold weather has been mixed.
Most of the time it has worked okay, but occasionally it hasn't worked. I would try
it and if it doesn't work in a short time, I would go back to fishing a nymph.

We will continue tomorrow.........

Copyright 2009 James Marsh