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Flyfishing the Montana Salmon Fly Hatch

Flyfishing the Montana Salmon Fly Hatch
The salmon fly hatch fits the old adage "big fly, big fish" perfectly. Photo by Chuck Robbins.

For most of us the salmon fly hatch is the main event on the annual Montana fly-fishing calendar — period, end of discussion. For example, as word spreads the Big Hole version is indeed imminent, anglers from all over come out the proverbial woodwork; a sort of whirlwind, mob-like affair more in line with rock concerts than mere insect hatches. Proof: the front page headline of Montana Standard (Butte) Sunday edition reads: SALMON FLY HITS BIGHOLE. That afternoon I count over 60 rigs at a boat launch where less than a dozen sat the previous afternoon. Weeks prior to the big bugs' earliest-ever appearance, fly shop phones start ringing, panting callers desperate to hear the magic refrain, "Yep, best drag butt or you'll miss it, sure."

The attraction is the possibility (real, imagined; no matter) of hooking the "trout of lifetime." Such as the 35-inch, 20-plus-pound monster brown trout Butte's Bob Kingston landed during the 2009 Big Hole blitz. In case you are interested, Kingston caught the beast using a 5-weight rod, pitching two salmon fly nymphs "right by the bank and he gobbled it up." (Good plan, by the way.) Rational thinking individuals realize the odds of catching such a fish are off the charts, but then, as we all know, not many of us are capable of such thinking, so €¦ .


The salmon fly is largest member of the aquatic insect family we call stone fly. At 2- to 3-inches long, food value-wise perhaps only the biggest, juiciest grasshoppers compare among insects. Unlike many aquatic insects that mature in about a year, the salmon fly matures in 2-3 years. The larval stage — nymph — possesses rudimentary (undeveloped) gills, and thus requires copious amounts of oxygen. Clean gravel and heavy water help to nurture, even speed up, the maturation process. Lousy swimmers, several days to a week or more prior to hatching, the nymphs crawl to the banks, up onto the nearest structure — rock, stick, bush, tree, tall grass stem, what have you — whereupon the skin (exoskeleton) splits, the adult crawls out and, just as feeble on the wing, flutters and/or crawls to a higher perch. In due time, mating takes place. Ever-clumsy, lovers often fall off, a faux pas trout seldom miss. Mated, the female flutters out over the river and, following repeated crash landings, dispenses eggs and dies; males simply die where they are and eventually fall into the river or are snatched up by ever-present, opportunistic birds.


Conventional wisdom is the hatch starts downriver and moves up. How far down and up depends and varies considerably year to year. The accepted average is 5-7 miles per day. Why the variation? I don't know. But, except for those times the hatch just explodes bugs everywhere all at once, it moves upstream over a period of days or even weeks, so you have plenty of time to get with the program. Fishermen being, well, fishermen, we all have our pet theories how best to proceed — chase the peak, stay ahead of the hatch, lay back and pick up the leavings or ignore the hatch altogether and go somewhere quieter. One time or another, all seem to have merit.


Drifting big stone fly nymphs in fast water is rarely a bad idea. Thus, my go-to rig is two big stone fly nymphs, tied on short, 4-inch droppers, 18-inches or so apart, depth and weight adjusted accordingly. Should that fail, I replace one stone fly nymph with a San Juan Worm or, based on the theory salmon flies aren't the only game in town, rig a big stone and a smaller nymph or even two smaller nymphs; PT, Hare's ear, Copper John, Prince, etc. can be deadly. For no other reason other than I like to cover all my bases, I often rig one guest with nymphs and the other with whatever dry stone fly pattern is hot. You never know unless you try it. This is, after all, fishing.


If I could somehow get the bugs and fish to cooperate, for me the salmon fly blitz would be one big dry-fly fest. There would be bugs in the air all day long and we'd pitch size 4 dries until our arms drop off or darkness falls, whichever comes first. Who among us doesn't thrill to the sight and sound of a big ol' trout smashing a big ol' dry to smithereens? Alas, absent flying naturals, dries work only sporadically at best, at worst not at all. For the purists in the crowd the best advice I know is to remain flexible, be ready to hit the river or meet your guide at a moment's notice. Generally not much happens until the air warms up. High, even muddy, water has little effect on egg-laying flights, but nasty weather — forget it. If I were to pick one time period it would be late afternoon to early evening, while bearing in mind all of this is way more crap shoot than science.


As you might expect, salmon fly patterns abound. The list is long and ever-changing. Today's hot item is likely to be toast even before the current hatch fades into oblivion. Over the years I have tied, tried and tossed countless should-a-knocked-'em-dead-but-didn't concoctions. More often than not, my innovations failed miserably. Non-tiers fear not, the clerks behind every counter in every fly shop in Montana are ready and more than willing to oblige. While it would seem even the most rabid innovators would have run out of ideas long ago, the smart money says, even as we speak, next season's must-have-sure-fire-killers are well on their way to the overseas factories for wholesale manufacture.

Every river has its favorites. For example, longtime Big Hole outfitter and guide Al Lefor, of Great Divide Outfitters, in Divide, says "[I]n dries, it's hard to beat Bird's Stonefly, Henry's Fork Salmonfly and the old standby Sofa Pillow. My top picks in the nymph department are Pat's Rubberlegs, Pepperoni and Bitch Creek. A few old guys still fish traditional stuff like the Bunyan Bug (dry), Grant's Woven-hair and Charlie's Brook's Montana Stone, but not many."

Big water, wind, heavyweight nymphs, split-shot and big, air-resistant dries dictate rods with a lot of backbone; 9- to 10-feet for 6- or 7-weight lines. Large arbor or mid-arbor reels make it easier to handle fish in heavy water.

It should go without saying, but exercise good landing technique. Try not to let the trout get downstream. Play the trout; don't let the trout play you. Keeping a bend in the rod and constantly changing the rod angle — left side, right side, high overhead — keeps the trout off balance and puts you in charge, not vice versa. Never point the rod at the trout. Let the reel's drag do its job and do not clamp down on a running fish.

The best fishing, nymph or dry, is usually near the banks, seams and mid-stream boulders in fast water and the bottom of fast water runs are always worth a shot. Trout gorge on the migrating nymphs, sometimes to the point of puking. Food for thought should you be in a dither where to launch your attack, ahead of, peak or behind. Regardless, aim for accurate, drag-free drifts. In my experience, you cannot place your fly too close; 4 inches off-target trumps 12 inches, and so forth. Strive for drag-free floats but don't be afraid to experiment. Sometimes slow-stripping or swinging nymphs or adding a slight twitch to a dry makes all the difference. Try not to get hung up on a single fly pattern, tactic or even stretch of river.


Salmon flies usually show up at Rock Creek, near Clinton, mid-May to early June. High water can muck up the lower river, calling for extra heavyweight nymphs, short leaders and stout tippets. Lacking reasonable visibility (1 1/2 to 2-feet or so) dry fly-fishing is an iffy proposition. Generally, the higher up, the better your chances of finding suitable conditions for pitching dries. During run-off the Rock really rocks and, floating or wading, you need to pay attention. And don't even dream of having a run to yourself; this one really draws a crowd. Top to bottom access is good.

Historically the Big Hole version starts around Notch Bottom about June 10, but don't count on it. Last year, for example, high, cold water put it off nearly two weeks. The best idea is to bug the local fly shops — in Dillon, Butte, Divide & Melrose — early and often. Locals say the hatch is at hand with the arrival of the western tanager and peak run-off is nearly a given.

In the canyons, large slippery boulders and heavy flows make wade-fishing difficult anytime. During run-off, rookie oarsmen need not apply. Last year one died and several others, including a couple veteran guides, experienced too-close-for-comfort wrecks. Word spreads quickly and the crowd grows exponentially daily. Road and ramp rage is common. The river below Glen is accessed off Burma Road, which in June can be difficult to navigate. Above Glen roads are paved, though narrow and twisty through the canyons. Access is easy throughout.

Starting about the same in Bear Trap Canyon, in semi-orderly and somewhat predictable fashion, the hatch makes it way up the Madison, arriving Ennis about June 20, and two weeks later between Quake and Hebgen lakes. Boat traffic between Lyons Bridge and Ennis is such you wonder if perhaps traffic lights might be in order. The good news, the river is pretty much all salmon fly water, allowing for at least some semblance of elbow room. Unlike the free-flowing Big Hole, flows are regulated by Hebgen Dam allowing for wade fishing except in really high-water years. South of Ennis numerous state fishing access sites allow make things easier. About two weeks later, the hatch starts on the Yellowstone River. Count on high and often muddy water to all but nix the dry-fly action. Casting nymphs to the banks is your best shot. Hit it right and the action can be off the charts. The upper river supports the strongest, most reliable hatch most years. Beware, Yankee Jim Canyon is dangerous. It has been known to eat drift boats such that even many local guides avoid it. There are numerous state fishing access sites south of Gardiner.

On the Gallatin River, ETA is July 1. The strongest hatch occurs in the canyon where fishing from a boat is verboten and borderline insane (class IV-V rapids) for all but the best river runners (technically legal to use a boat for transportation, but few do). Anyway, access is easy off U.S. 191 (heavy traffic, narrow and twisty; use extreme caution). Some of the land beside the highway is private, so don't climb any fences except at the bridges where Montana Stream Access Law allows angler access. The river will be high. Heavily-weighted nymphs and added split-shots rule, and dry-fly action is spotty to non-existent. Like the highway, wading is treacherous to downright deadly.

Though most of Yellowstone Park is technically not Montana, it's close enough should you want to continue your quest. Early to mid-July is salmon fly time. For up-to-the-minute information, contact the fly shops in Gardiner or West Yellowstone.

The Smith River also plays host to the big bugs, starting in mid-May, but you need a permit to float the canyon (best salmon fly water) and floating requires overnight camping. Contact Montana Fish, Wildlife and Parks for information and to begin the permit application process.

Golden stones often overlap and are a size or two smaller than salmon flies, but the trout don't seem to discriminate. Two of the best spots to fish this mixed bag are the Boulder (Big Timber) and Stillwater (Columbus) rivers.

So, there you have it. As a friend likes to say,, "Get yourself gainfully unemployed, financially independent, retired, divorced or just turn plain irresponsible. Why, hell, think of it: Nothin' but big bugs for two whole months €¦ all on a Montana ticket yet besides."

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