The lifecycle of these prehistoric-looking insects begins with nymphs that spend three years growing in the rocky river bottom, molting up to 23 times before emerging. During the hatch, these armored nymphs migrate toward streamside vegetation, where they crawl out of the water, split their exoskeletons and emerge as orange-bodied adults.

The winged adults remain near the water for several days, providing a brief window of extraordinary dry fly fishing in Montana.

Prime Montana Rivers for Salmonfly Action

• Madison River: The stretch between Quake Lake and Ennis is home to one of the best salmonfly hatches in Montana, typically in mid-late June. Heavy pocket water and undercut banks provide prime holding water for the wild trout feeding on these massive bugs. Floating the Madison River sections between Lyon’s Bridge and Ennis during this hatch is a bucket-list fly fishing experience for every serious fly angler.
• Gallatin River: This wild freestone Gallatin River offers some of the best fly fishing in Montana during June and early July. Salmonflies first appear in the Gallatin Valley and then the hatch intensifies as it erupts in the canyon sections shortly thereafter. River levels are usually high at this time of the year and feeding trout hold tight to the banks. Wading or fishing from the bank with big dry flies is the best tactic.
• Yellowstone River: Timing is everything when fishing the salmonfly hatch on this legendary Montana River. Expect the river to be off-color and running high, but the fish will be eager to rise a well-presented big bug. Floating the river in late June is a solid strategy for anglers hoping to catch the salmonfly eruption on the Yellowstone River in Montana.
• Big Hole River: Known for its prolific salmonfly activity from Divide to Melrose between late May and mid-June. Prolific insect activity and high flows keep trout near the banks where they are best reached while floating. This is one of the premier hatches in Montana and attracts anglers to the Big Hole River from around the world. This is primetime for trophy brown trout and hard-fighting rainbows on big dry flies.
• Blackfoot River: Perhaps the most famous river in western Montana fly fishing lore, the Blackfoot River is at its prime during the salmonfly emergence. Rock gardens, deep runs, and ripping back-eddies hold feeding trout during this high-water time of year. Expect fish to hold tight to structure in soft water. Advanced anglers do well here as accurate, quick presentations are the key to angling success.

Essential Salmonfly Patterns

Top 5 Salmonfly Dry Flies

• Henry’s Fork Foam Stone: This salmonfly imitation floats high, is easy to see, and fish eat them! A Mike Lawson creation for fly fishing the Henry’s Fork River, anglers everywhere can count on this pattern.
• Fluttering Stone:This dark foam pattern sits low on the water and is a Montana fishing guide favorite when the trout start to become wary with heavy angling pressure.
• Flutter Bug: Feathers, foam, and fur all come together to create this phenomenal salmonfly imitation that works extremely well during the peak of egg laying activity.
• Pteronarcys Chubby Chernobyl: The perfect color combination when both golden stones and salmonflies are out in big number. Available in a wide range of sizes, we find that #6-#10 to be ideal for fly fishing in Montana during the salmonfly hatch.
• Dancin Ricky: A low floating foam that is fished dead-drifted, twitched, or even swung along undercut banks when the salmonfly nymphs and adults are concentrated along bankside structure.

5 Essential Salmonfly Nymphs

Pat's Rubber Legs: Essential nymph pattern for fishing deep runs before and during the hatch. Most effective in sizes 4-8 with black or brown and black, variegated chenille.

Bitch Creek: A Montana fly fishing classic, this woven chenille bodied nymph still excels on the Big Hole and Madison rivers throughout the early stages of the hatch.

Biot Epoxy Stone: Our guides rely on the dark-colored version during throughout the hatch fished as a dropper below a big dry or nymphed below a strike indicator.

Tungsten Rubber Leg: Fish these in the black or brown colorways in sizes #8-#10 below a big dry when there are a lot of bugs around but the dry fly bite is slow.

Beadhead Prince Nymph: This generalist nymph pattern works surprisingly well during the salmonfly hatch whether fished under an indicator or as a dropper when water clarity is rapidly clearing.

Angling Tips For The Salmonfly Hatch

Fly Rod: High water and unpredictable Montana weather, coupled with casting heavy, air-resistant flies calls for a fast-action 6-weight like the St. Croix Evos, Sage Igniter, or G. Loomis NRX+.

Fly Line: Floating fly lines that are overweighted with a short front taper will quickly turnover heavy rigs for short, accurate casting. The Elite RIO Grand really shines in these situations.

Timing: Fly fishing in Montana during the salmonfly hatch is popular with both local and traveling anglers. Expect the busy rivers and be willing head out early or late to find rested trout.

Casting: Salmonfly season coincides with the tail end of runoff so the rivers are usually high, but dropping. Practice casting before you go, use short leaders, and be prepared for lots of casting to stationary targets while floating.

Floatant: Be prepared with both liquid and powder desiccant floatants as they are used often and liberally to keep those big dry flies floating in high water. Fly Agra and Top Ride are favorites.

Experience Montana Fly Fishing at its Peak

The salmonfly hatch represents the pinnacle of Montana's dry fly fishing calendar when conditions are right. Many anglers miss out on fishing this hatch because they are concerned about volatile water conditions. With nearly 25 years of experience guiding Montana fly fishing trips, we have come to appreciate this time of year as one of the best for experienced anglers.

Our veteran Montana fishing guides bring decades of experience on Montana's premier rivers, providing advanced tactics and access to the most productive stretches of water. Contact us to reserve your guided Montana fly fishing trip during prime salmonfly season, where we'll focus on the specific rivers and techniques that match your skill level and preferences.