Understanding Stoneflies: Lifecycles and Common Species

These large, protein-packed insects emerge in several waves throughout the fishing season, offering prime opportunities for both dry fly and nymphing techniques.

Their lifecycle includes a prolonged nymph stage, where they thrive in well-oxygenated, fast-moving waters, and a brief adult stage during which they mate and deposit eggs.

Montana is home to several stonefly species hatches that are of angling significance, each with its unique timing and characteristics:

Salmonflies: The giants of the stonefly family, salmonflies emerge in late spring to early summer. These orange colored behemoths hatch by the tens of thousands on some of Montana’s most famous trout waters.

Skwala: One of the earliest hatches of significance during the season, skwalas appear in late winter to early spring. The rivers near Missoula, Montana come alive with anglers and trout once they appear with regularity.

Golden Stones: A midsummer favorite, these medium-sized stoneflies are prevalent in many of Montana’s rivers. They hatch in large numbers alongside the salmonflies, becoming more sparse – yet always around – through the summer months.

Yellow Sallies: Smaller and more delicate, yellow sallies are pale in color with a splash of red near their tails. These diminutive stoneflies are important to trout as both nymphs and adults in June and July on the legendary Montana fly fishing rivers around the Big Sky state.

5 Top Rivers for Fly Fishing in Montana During a Stonefly Hatch

1. Madison River - The Madison River’s fast, oxygen-rich waters are ideal habitat for stoneflies. Salmonfly hatches erupt between Quake Lake and Ennis during late June and early July, bringing a week or two of outstanding dry fly fishing. Golden stones and yellow sallies begin hatching within days of the first adult salmonfly sightings. Although the yellow sally hatches wane by late July, anglers fly fishing the Madison River continue to encounter golden stones well into September.

2. Big Hole River - Known for its diverse hatches, the salmonfly hatch of the Big Hole River is perhaps the most iconic of western hatches. The river’s mix of runs, pools, and riffles provides an ideal habitat for stoneflies and holds large, aggressive trout. River levels drop quickly by late June and the mad rush of stonefly season comes to an abrupt end on the Big Hole.

3. Yellowstone River – Originating out of Yellowstone Lake, this legendary Montana river is the longest undammed river in the lower 48. With their fast currents, the upper river sections are home to spectacular stonefly hatches throughout July. Salmonflies, golden stones, and yellow sallies are key to feeding trout as the Yellowstone River level drops when the runoff season comes to an end.

4. Beverhead River – This small tailwater fishery sees an explosion of yellow sallies in June and July. The highly selective rainbow and brown trout of the upper Beaverhear River sections near Clark Canyon Dam key into both nymphs and dries during the early summer frenzy.

5. Bitterroot River - The Bitterroot is world-renowned for its early-season skwala hatch, which kicks off Montana dry fly fishing near Missoula in late March. The Salmonfly and golden stone hatches are less dramatic when compared to the Big Hole or Rock Creek. However, the fish key into them when they are around, and the angling pressure is light. The upper Bitterroot River and its tributaries – especially the West Fork – are stellar dry fly fisheries from Arpil through mid-June.

Top 10 Flies for Fly Fishing in Montana During Stonefly Hatches

Stonefly Dry Flies

1. Chubby Chernobyl: A versatile pattern that is available in a wide range of sizes and colors. From skwalas to yellow sallies, there is a variation that floats high, is easy to see, and trout eat.

2. Stimulator: A classic dry fly originated by Randall Kaufmann on a long, curved-shank hook and heavily hackled to maximize buoyancy. Montana fishing guide essentials include the orange in a size 6, olive in a size 10, and yellow in a size 14.

3. Flushfloater: This Mike Mercer original floats low on the surface to fool wary trout late in a hatch. Oversized wings add a realistic profile from underneath and the hi-vis wing is key for the angler when fishing this in the salmonfly, golden stone, or Skala version

4. Water Walker: An all-foam-bodied imitation available in a wide range of sizes and colors. Montana fishing guides consider the tan, circus-peanut, yellow, and orange colors as staple patterns in their summertime fly boxes.

5. Rogue Foam Stone: Designed to mimic skwals,golden stones, and salmonflies, its foam body ensures excellent flotation while sitting low in the surface film.

6. Cat Puke: A Rainy’s Flies classic pattern available in salmonfly and golden stone colors. The oversized wing and x-tube body give uncanny realism to these giant dry flies that are near perfect replicas of an egg-laying adult.

Stonefly Nymph Patterns

7. Pat’s Rubber Legs: A go-to fly pattern for stonefly nymphs, its realistic movement works year-round, and it’s available in a wide range of sizes and colors. Works well under a strike indicator or as a dropper off of a large dry fly

8. Poxyback Stone: Both the dark and light colors are great for fly fishing in Montana during the winter and spring months, before the summer stoneflies kick into full gear. They are effective imitations for golden stone, skwala, salmonfly, and yellow sally nymphs.

9. Psycho Prince: Ideal for smaller stoneflies like yellow sallies and the little black stones of winter, this modern take on the beaded prince nymph is a must have for anglers fly fishing in Montana during the midsummer season.

10. North Fork Special: Whether fished as a dropper off a big dry during a Madison River Salmonfly hatch or under a strike indicator on the Gallatin River, this realistic stonefly nymph is a Montana angler favorite.

Angling Tips for Fly Fishing Stonefly Hatches in Montana

Best Time of Year: Stonefly hatches occur throughout the Montana fishing season, with skwalas appearing in early spring, salmonflies in late spring to early summer, and golden stones and yellow sallies following in midsummer. Primetime is typically from early June through mid-July.

Presentation Technique: Trout prefer stonefly dries that are fished with a drag-free presentation, imitating a “spent” adult. Rising fish are rarely seen as trout feed on the adults in an opportunistic manner – look for explosive rises when targeting actively feeding fish.

Rod and Fly Line Recommendation:

A 9-foot, fast-action 5-weight fly rod like the Sage Igniter, St. Croix Evos, or G. Loomis NRX+ is a versatile choice that can handle dries and nymphs. Pair these rods with a Scientific Anglers Amplitude Infinity or Elite Rio Gold for optimal casting performance using oversized stonefly patterns.

Experience Montana Fly Fishing with Fins and Feathers

Fins and Feathers Guide Service has been outfitting Montana fly fishing trips since 2000. Join us in late June for the madness of fishing the Salmonfly hatch for a western bucket list fly fishing experience. Yellow sallies and golden stone emergences persist throughout the early summer, ensuring daily dry fly fishing opportunities.

Contact us for help with planning your Montana fly fishing vacation. Reservations can be placed online, via e-mail, or by calling us at 1-406-468-5019.