FLY FISHING THE BITTERROOT - Montana

A River of Change and Challenge

By Justin Karnopp

The banks of the Bitterroot River are a good place to ponder. In the shadow of the namesake snow-capped peaks, the mind is free to wander, like the deer, elk, moose, bears and raptors that thrive in mixed forests of poplars and pine. The river itself is a mesmerizing jewel, the flow a rich tapestry of emerald and garnet. Perfectly camouflaged within this medium are the river’s primary attractions, wild brown and rainbow trout, introduced to Montana’s rivers in the 19th century, and bull and Westslope cutthroat trout, native to these waters since time immemorial. Artists and anglers find inspiration here, and for those with a propensity for both, images of feathers, fur, and foam begin to take shape in the easel of the imagination. The impetus for some of the most effective dry fly patterns ever developed, relied upon by fly fishers the world-over, can be traced back to a moment on the Bitterroot, when a fish posed a problem and an angler/artist set out to solve it. And the problems posed by this hallowed trout river are many.

The Bitterroot is highly schizophrenic, more so than any other freestone (undammed) trout river I have fished. For 15 years, this stream has consistently flummoxed me as both a guide and angler. One minute, the trout are freely rising to my dry fly, and the next, there is no sign that a fish even resides here. I hypothesize that the river’s inconsistency is partly due to the presence of the towering Bitterroot Mountains themselves. This range reaches for the 10,000-foot mark and forms a barrier to storm fronts rolling in from the Pacific Ocean, 1000 miles to the west. Eventually, the saturated clouds unleash enough precipitation in the Idaho wilderness to rise up and crest the Bitterroot Range. A pleasant afternoon can quickly turn sour, with rain, snow and especially wind, the bane of all fly anglers, rushing down the slope of the mountains. These events cause drastic changes in the barometric pressure. Fish maintain equilibrium in the aquatic environment via an internal air bladder, which acts as a sort of ballast. Fluctuations in the barometer interfere with this system and disrupt their feeding behavior.

Every May, the snowpack on both the gentle Sapphire Range to the east and the imposing Bitterroot Mountains to the west, succumb to the long-awaited arrival of spring. The meandering flows of the river balloon into a raging torrent. Hardwoods fall first, and on particularly severe events, mature pine trees end up in the riverbed. By late June, the surge of runoff is well on its way downriver, the river resumes its meandering course, but the chaos of runoff has left its mark. An influx of woody debris creates essential trout habitat, affording shady haunts for fish to find respite from current and predators, but can spell trouble for boaters and anglers. Side channels change and “sweepers”, fallen logs that can trap a raft, drift boat, or inner tube, are extremely dangerous. The river is never the same after runoff, and requires careful exploration, scouting, and gathering of local intel from fly shops, guides, and Montana Fish, Wildlife and Parks.

The Bitterroot is several separate streams rolled into one 84-mile long conundrum. The upper river, above the hamlet of Hamilton, is a rather turbulent system featuring a rocky substrate. This habitat is ideally suited to native Westlope Cutthroat, rainbows, and Cuttbows (hybrids between the two subspecies). These fish, the cutthroat in particular, tend to be easier to dupe on an artificial fly than brown trout. Why? I have no idea, but the upper river, in general, is a better destination for those anglers still working out the kinks in their fly fishing abilities.

The lower river, from Victor down to the confluence with the Clark Fork in the bustling college city of Missoula, is a good place to hone the finer points of fly presentation and the many athletic nuances involved in the sport of fly fishing. The river gains volume via multiple tributaries, flushing glacial till into the substrate and adding more fallen timber. The alluvial plain is wider on the lower river and coupled with the south-north orientation, the Bitterroot tends to flow warmer in the summer months, giving the edge to the hardier brown trout. Suspicious browns, some of them near the magical two-foot mark in length, prowl the flats around Stevensville and carefully inspect their meals before committing to eat.

The lower river is also home to northern pike, and fishing for these introduced predators is a retreat from persnickety trout. While most fly anglers tend to release the river’s trout, pike are often removed from the system and wind up in beer batter.

Northern Pike

While some anglers prefer to probe the Bitterroot’s deep lies with nymphs or streamers, throughout its course, the river is largely considered in terms of the dry fly presentation. The bulk of the thousands of anglers that make the pilgrimage each year come for one of the famed insect emergences that bring the fish to the surface. The first such event occurs in March/April, when the Skwala stonefly and March Brown mayfly hatches coincide. Postrunoff, in June/July, expect a top water smorgasbord with caddisflies, mayflies, stoneflies, and ants/beetles on the menu. In September/October grasshoppers find their way into the drink and on cool, fall days, the mayfly hatches can be outstanding.

Thanks to Montana’s stream access law, anglers can find numerous places to enter the river and spend the day wade fishing. For those with a boat, a dozen public boat launches line the main river between Hannon Memorial Bridge and the town of Lolo. Hiring a local, professional guide can greatly flatten the learning curve.

A 9-foot 5 or 6 weight is the most common fly rod on the Bitterroot, but the most important implements that a fly angler can bring to the water is a good selection of locally designed fly patterns…and a heavy dose of humility.

Many times, I have been on the river when no fish were rising, only to discover that one of my friends, floating a few miles upstream, encountered a dry fly event and enjoyed exceptional fishing. Unpredictability is the Bitterroot River’s curse and charm, and the river and the trout excel at the game of hard to get.

About the author: A longtime guide, writer and fly tyer, Justin Karnopp is the father of two, Sawyer (7) and Odessa (4), and the Principal of CD Fishing USA (www.cd-fishing.us), the North American Distributor for Composite Development Fly Rods. Justin and his wife, Lauren, produce a fly fishing podcast (www.thefebruaryroom.com) from their Missoula home. Find more of Justin’s work at www.justinkarnopp.com