Hatches Made Easy:

American March Brown - Duns

I hope you don't start reading this article about the March Browns if you haven't
read the first two because I don't intend to repeat the previously mentioned
concerns about fishing this hatch. The American March Brown dun is certainly a
beautiful mayfly. It is so large and colorful that you would think every big trout in
the stream would focus on eating them. However, I just haven't found that to be
the case. For one thing, big fish don't necessarily eat big mayflies. Before I give
the wrong impression, let me point out that the trout do eat the duns. There is no
question about that. You may even see that happen every once in a while.
You want to be aware of the fact that these mayflies will probably be
found in different sizes during the long hatch.
They will not vary in size at
any one specific time but they will from the start of the hatch to the end of it. The
"Gray Fox" looking March Brown will appear and will look like a different mayfly.
That fact hasn't changed. As we previously said, it is just that the mayfly anglers
previously called the "Gary Fox" was discovered to be the same mayfly as the
American March Brown. This change in appearance of the March Browns will not
just suddenly happen one day. The duns will gradually transgress in sizes and
shades of color throughout the long hatch period. These mayflies can vary in
terms of hook sizes of their imitations from a 10 to a 14, although most of them
will be closer to a size 12. I will not get into the fly patterns for the March Browns
just yet, but when I do you will discover that I don't think much of most of the
commercially available flies for this one.  

Most Smoky Mountain anglers fish imitations of the March Brown dun just like
they fish most any other mayfly imitation. They just toss them in the fast water
runs and riffles as they progress upstream unaware that is not where the March
Browns hatch. When they do this, every once in a while they will catch a trout. In
the fast water at the right time and place, an opportunistically feeding trout would
eat an imitation of baby rat; or I should say, a fly that doesn't imitate anything.
Typically, the forefathers and teaches of some Smoky Mountain anglers beat
this one method of fishing in their kids and students heads. The "I've been
fishing these streams for fifty years" line sounds very convincing until you
discover they have been fishing for fifty years using a less than productive
method when imitating many of the aquatic insects. It is possible that a dun may
not get off the water quick enough to avoid being caught in the fast currents but
that approach to fishing imitations of the dun is a far cry from the most
productive approach.
If you are going to imitate a March Brown dun, you need to present the
fly in the places the March Browns hatch.
If you are not sure where they
hatch then I suggest you go back and read the first two articles. Obviously, in
the type of slow moving, smooth water they do hatch in, you imitation shouldn't
be a heavy hackled, high floating imitation designed for fast water. It should  be
a more realistic, low floating imitation of a March Brown dun. On colder days,
these duns can struggle around on the surface long enough to get caught up in
the nearby fast water but most of the time all but the cripples will be air borne
long before the currents catch them.
If possible, you should present the fly with an upstream or up and across cast.
You can get closer to the fish fishing upstream. However, you may find that may
not be the most productive way to get the fly to a likely spot. A longer
downstream or down and across presentation may prove to be the best way to
present the dun imitation. I don't intend to get into presentation techniques, I just
want to point out that you need to get the fly in the areas of water where the
March Browns hatch - that is slow moving, smooth water that is adjacent to or
nearby the fast water where they spend most of their life. If you do that at the
right time and place using a good imitation of the dun, you will get the type of
explosive reaction that makes dry fly fishing so great.

Coming Up Next:
The March Brown Spinners

Copyright 2008 James Marsh