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Fly Tying: American Brown March

Fountains of Youth – Classic trout flies that have withstood the test of time … flies that remain “forever young”

by Rusty Dunn

Trout fishing in America used to be dead easy.  Find any cold clear river … cast a brightly colored fly … catch a sizeable brook trout … repeat as needed.  On Febru­ary 28, 1883, however, things got much more difficult.  The days of effortless trout were over.  What happened?  Eighty thousand brown trout eggs ar­rived from Germany at the state fish hatch­ery in Cold Spring Harbor, NY.  These eggs and others that fol­lowed were planted in New York rivers and, eventu­ally, throughout the eastern seaboard.  The immi­grants thrived in the New World, and within 20-30 years, brown trout were the dominant trout of the East.  Some anglers praised the new species for being a more worthy adversary.  Others scorned it for displacing native brook trout.  Brown trout “aggres­siveness” was blamed for declining numbers of brook trout, but diminished water quality in an increasingly industrial nation was at least as impor­tant.  Brown trout are more tolerant of marginal wa­ters, and they colonized habitat that no longer sup­ported brookies.  Brook trout would have been dis­placed by chubs and dace were it not for arrival of the brown trout.

Brook trout are famous for taking showy attractor flies, but brown trout are more reserved.  They are cunning, judgmental, and, down right opinion­ated.  Brown trout require more stealth, bet­ter presenta­tions, and a more exact imi­tation.  This drove refine­ment of American fly fishing tackle and technique.  Fortu­nately, fly anglers of Great Britain had shown the way.  Brown trout are the only native trout of Europe, and “matching the hatch” had been routine for dec­ades on the other side of the pond.

Today we take for granted extensive hatch charts and matching flies, but where does this in­formation come from?  Observant anglers doubling as amateur entomologists patiently and systemati­cally collect aquatic insects, identify species, and catalog times and dates of emergences.  Fly patterns to match the naturals can then follow.

The great pioneer of insect identification and hatch matching was Englishman Alfred Ronalds (1802-1860).  He merged the ecology of trout and trout stream insects with angling and fly design.  His 1836 book The Fly-Fisher’s Entomology catalogs insects of British trout streams and describes 89 matching fly patterns.  Ronalds established the practice of sys­tem­atically matching hatches, and his book is one of the great landmarks in the history of fly fishing.

English hatches and patterns are not directly applica­ble to North America, because the insect species are differ­ent.  The tradition of angling entomology in North America was established by Preston Jennings (1893-1962), who is often described as “the American Ronalds”.  He did for the US what Ronalds had done for Great Britain.  Jennings was the first American an­gler to broadly in­tegrate aquatic entomology with fly de­sign and an­gling methods.  Jennings’ 1935 book A Book of Trout Flies, describes major hatches of the East and iden­tifies flies to match.  It is precise, beauti­fully illus­trated, and elegant.  Jen­nings set the stand­ard for generations of later Ameri­can au­thors who ex­tended his pioneering work.

The most famous flies of Preston Jennings are the American March Brown and the Grey Fox.  March Browns (Stenonema vicarium in the East) are one of the largest mayflies of the early season, appearing shortly after Hendricksons (late May/early June).  Jennings’ fly is called the American March Brown to distinguish it from the March Brown of Great Britain, a different species that actu­ally hatches in March.  The American March Brown imitates large gin­ger/tan/light brown mayfly duns, but many anglers fish it quite suc­cessfully as an attractor dry.

March Brown duns hatch slowly but steadily through the day and are easily overlooked.  Spinners, how­ever, gather at dusk in concentrated mating flights.  If you’re fishing the Driftless at dusk in early June, the last thing you should do before driving away is look upwards.  If March Brown spin­ners swarm overhead, don’t leave the stream without enjoying one of North America’s truly fine spinner falls.


Copyright 2017, Rusty Dunn

American Brown March

Hook: Dry fly, #10-12
Thread: Orange
Tail: Hackle barbs of a red game cock
Wing: Flank feather barbs of a mallard drake, upright and divided
Body: Red fox belly fur mixed with sandy fur of a hare’s poll
Hackle: Red game cock and grizzly, with the grizzly feather nearer the hook eye

Hook: Dry fly, #10-12
Thread: Orange
Tail: Hackle barbs of a red game cock
Wing: Red fox belly fur mixed with sandy fur of a hare’s poll
Hackle: Red game cock and grizzly, with the grizzly feather nearer the hook eye