Insects and other foods the trout may be eating:
1.   Blue-winged Olives
2.   Little Black Winter Stoneflies
3.   Quill Gordon Mayflies
4.   Blue Quill Mayflies
5.   Little Brown Stoneflies
6.   Little Black Caddis (American Grannoms)
7.   Hendricksons and Red Quills
8.   Little Short Horned Sedges
9.   American March Brown
10. Sculpin, baitfish and small crayfish (Imitate with streamers)
11  Midges

American March Browns - Spinner
The American March Brown spinner is normally the best stage of the hatch for
catching trout. The problem with it in the Great Smoky Mountains National Park is
that it often occurs after legal fishing hours. During the first part of the hatch period,
such as from now until about the first week or two of May, you may catch some
spinners on the water before legal fishing hours have ended. This is normally during
cloudy, overcast days.

The good thing about the spinner fall is that it concentrates those March Brown
mayflies that have hatched off and on all day into one short time period that only
last about an hour at the most. If the spinner fall contains enough of the mayflies,
and it sometimes does, it will really turn on the trout.

It is very difficult to see these spinners even though they are very large, ranging
from a hook size 10 to 12. The normal low light conditions makes it difficult. If you
are wading, you can often see them spent, drifting right by you, but to spot them
several feet or yards away, is almost impossible.

The good thing is that during the long two month hatch period, there are usually
other mayfly spinners on the water at the same time. Those could be Light Cahills,
Cream Cahills, Slate Drakes, Sulphur, Eastern Pale Evening Duns,
Blue-winged Olives (Eastern BWOs) and others. None of these mayflies are
hatching now, but they will within the next two months and the spinners will be mixed
in with a few March Browns. The problem is, the later in the year it is, the warmer it
is likely to be and the later in the day the spinner falls will occur.

Most all of the spinners turn a darker, rusty brown color similar to the American
March Brown Spinner. The big difference would be the hook size. All of the other
mayflies I mentioned above, with the exception of the Slate Drakes, are much
smaller than the March Browns. The bottom line to all of this is that on any given
day for the next two months, it is a very good idea to try a spinner imitation of the
March Brown or smaller mayfly the last thirty minutes of the time you can legally fish
in the park. Normally, you will do very good. You may possible catch several trout in
a very short time. I have done this on many occasions on a spinner imitation.
"Perfect Fly" American March Brown Spinner