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

by Rusty Dunn

Have you ever thought about designing the perfect trout fly? A fly that is simple, tied with readily available materials, and so effective it catches trout regardless of the hatch. A fly that imitates – or is at least perceived by trout to imitate – mayflies, caddisflies, stoneflies, terrestrials, crustaceans, and even midges. One that finds trout even when the water appears lifeless. A fly so versatile that your stuffed-to-the-gill fly boxes could all be replaced by one small tin tucked in a shirt pocket. Well, fantasize no longer my friend. Your fly is at hand. It was designed over 300 years ago, but maybe you missed it.

March Brown mayflies are the first large aquatic insects to hatch in an English spring, usually appearing in mid-March. Hatches of North American March Browns (two distinct spe­cies) commence in mid-March to early July depending on the species and geographic location. March Brown imi­ta­tions are among the oldest fly patterns in recorded his­tory. The very first English-language angling manuscript was authored by Juliana Berners in 1496 (A Treatyse of Fysshynge wyth an Angle). Her “donne flye” was one of 12 described fly patterns, and many angling scholars believe it imitated March Browns. Berners’ descriptions of insects and their imitations, however, were so brief and general that uncer­tainty still persists about which insect(s) each fly imi­tated. Similarly, Charles Cot­ton’s 65 fly patterns added to the 1676 edition of Isaak Walton’s The Compleat Angler do not unambiguously include a March Brown imitation.

The March Brown era began in earnest in 1689 with publi­cation of James Chetham’s 2nd edition of The Angler’s Vade Mecum. Chetham described a “Moorish Brown” arti­ficial fly that almost certainly imitates the mayfly we now call ‘March Brown’. A fly explicitly named “March Brown” appeared in print in 1800 with George Scotcher’s The Fly Fisher’s Legacy, although the name was likely in common usage well before that. ‘March Brown’ remains today the com­mon name for both insect and artificial fly.

March Browns are found in rapid, well-oxygenated, free­stone streams, but they are rare or completely absent in slow silty streams. Nymphs are brown to reddish brown clingers. Duns are large (hook sizes #10 – #12), brown to gray­ish-brown in color, and seg­mented with highlights of pale yel­low. Wings are dun-colored and darkly mottled grayish brown. Spin­ners look similar to duns but with trans­lucent wings.

Generations of highly respected authors have praised effectiveness of March Brown flies, especially wet-fly pat­terns. They note that even when plentiful March Brown duns drift atop the surface, wet flies are usually more effec­tive than dries. March Brown nymphs swim poorly and require considerable time to reach and transit through the sur­face film during a hatch. Therein likely explains the superi­ority of wet flies. Such authors additionally note that March Brown wet flies are effective long before and long after the known weeks of March Brown emergence. March Brown wets are excellent even in rivers that are com­pletely devoid of the naturals. March Brown magic is not limited to mayfly imitation either. Many accom­plished authors praise March Brown wets when trout actively feed on cad­disflies, stone­flies, crustaceans (e.g. scuds), certain terres­trials (e.g. grass-moths) and, yes, even midges (large sizes for stillwaters; tiny sizes for rivers and streams).

Thus, despite the name “March” and despite a long history of use to imi­tate a specific hatch, March Brown wet flies are excellent general attractors that can be effective in all waters at all times. Only a cherished few fly patterns can make such a claim. Famed Norwegian outdoor adventurer Fridtjof Nansen succinctly summarized March Brown prow­ess thusly, “Give me two March Browns and a box of matches and I’ll survive the whole summer”.

After 300-plus years of tinkering and substitution, thou­sands of March Brown dressings have been described. Nymphs, emergers, duns, and spinners with seemingly endless permutations of threads, furs, feathers, fibers, and colors have been published. Soft-hackled March Brown Nymphs have proved to be espe­cially effec­tive and versa­tile. They can be fished deeply to imitate nymphs or larvae near the bottom, swung across currents or rising upward to imitate ascending nymphs or pupae, just under the sur­face to imitate transitional nymphs or pupae, or awash in the sur­face film to imitate struggling emergers, failed/drowned duns, and spent spinners.

Copyright 2026, Rusty Dunn

March Brown Nymph 

This is Jim Leisenring’s pattern for the March Brown Nymph (The Art of Tying the Wet Fly, 1944). For use as a general wingless wet attractor, vary hook sizes & colors as desired.