Chasing the Salmonfly Hatch: A Guide to the West's Most Legendary Emergence

Quick Reference

River	State	Typical Timing	Peak Window	Best CFS Range
Henry's Fork	ID	Mid-May	Memorial Day week	800-1,500
Deschutes	OR	Early May - Mid-June	May 5-15	3,640-7,000
Rock Creek	MT	Early June	June 1-10	400-800
Madison	MT	Mid-late June	June 20-July 4	800-1,200
Big Hole	MT	Early-mid June	June 10-July 1	800-1,500
Yellowstone	MT	Late June-July	July 1-10	2,000-4,000
Upper Colorado	CO	Late May-June	Early June	800-1,500

Key Temp Trigger: 54-58°F | Hatch moves upstream: 2-5 miles/day | Best timing: 10-14 days before peak OR 2-3 days after

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The Salmonfly Hatch: What Makes It Special

There's a moment during Salmonfly season that hooks anglers for life. You're standing knee-deep in a Montana freestone, willows heavy with giant orange stoneflies. A 3-inch bug tumbles off an overhanging branch and lands on the water with an audible splat. Before it can twitch, the surface explodes. A brown trout the size of your forearm crushes the bug and disappears into the foam. Your hands shake as you false-cast toward the bank.

The Salmonfly (Pteronarcys californica) hatch is the most anticipated event in Western fly fishing. These prehistoric-looking stoneflies measure 2.5 to 3 inches long, making them the largest aquatic insects in North American rivers. When they emerge in late spring and early summer, trout that normally ignore dry flies will crash the surface with reckless abandon.

The hatch creates a brief window of chaos. Clumsy adult Salmonflies flutter, crash-land, and struggle on the surface. Trout go on a feeding binge. Fish that normally require 7X tippet and perfect presentations will eat a big, ugly foam fly slapped against the bank. It's dry fly fishing at its most violent and exciting.

But here's what nobody tells you until you've blown a trip: the Salmonfly hatch is notoriously difficult to time. The emergence window is narrow (often just 3-5 days of peak activity per river section), it moves upstream as water warms, and conditions vary dramatically year to year. I've seen the Madison hatch arrive two weeks early in warm years and a week late after cold springs. This guide covers everything you need to know to chase the hatch across the West - and actually catch it.

Understanding the Hatch

The Life Cycle

Salmonfly nymphs live 3-4 years in the river before emerging as adults. They're found only in cold, clean, well-oxygenated water with rocky bottoms. The nymphs crawl among cobble and boulders, feeding on decaying organic matter and algae.

When water temperatures reach 54-56°F, mature nymphs begin migrating toward the banks. This pre-emergence activity starts 10-14 days before adults appear on the surface. During this period, nymph fishing can be exceptional as thousands of large stonefly nymphs become available to trout.

The nymphs crawl out of the water onto streamside rocks and vegetation, typically at night or early morning. The adult stonefly emerges from the nymphal shuck and spends several days resting in bankside willows and brush before mating. After mating, females return to the water to lay eggs, creating the dramatic surface activity that makes this hatch famous.

Temperature Triggers

Water temperature is the key variable. The magic range is 54-58°F:

• Below 54°F: Nymphs stay deep, minimal migration
• 54-56°F: Nymph migration begins, pre-hatch fishing window opens
• 56-58°F: Peak emergence, adults on the water
• Above 58°F: Hatch progresses upstream toward cooler water

The hatch moves upstream at roughly 2-5 miles per day as water warms at higher elevations. On large rivers, this progression can extend the fishable window to several weeks if you're willing to follow it.

The Six-Week Window

Across the Western U.S., the Salmonfly hatch spans roughly six weeks from mid-May to early July:

Timing	Rivers	Notes
Mid-May	Henry's Fork (ID), Lower Deschutes (OR)	Earliest hatches
Late May - Early June	Rock Creek (MT), Upper Deschutes (OR)	Warming into season
Mid-June	Madison, Big Hole, Lower Yellowstone (MT)	Peak Montana action
Late June	Upper Madison, Upper Yellowstone (MT)	Moving upstream
Early July	Upper reaches, park waters	Highest elevation waters

Top Salmonfly Rivers

Montana

Montana is the epicenter of Salmonfly fishing. The state's freestone rivers produce the most consistent hatches in the West.

Madison River

The Madison is often called the best Salmonfly river in America. The "50-Mile Riffle" from Quake Lake to Ennis Lake holds enormous populations of these insects.

Timing: June 20 - July 4 (typical two-week window)

• Hatch appears near Ennis around June 20th
• Peaks by June 25th throughout the float section to Lyons Bridge
• Reaches upper section near Quake Lake by July 1-7

Progression: The hatch moves upstream roughly 3-5 miles per day. If you're fishing the Lyons Bridge to McAtee section on June 22nd and it's slow, try further downstream toward Ennis. Check back upstream in a few days.

Flow Windows (USGS 06040000 - Cameron):

CFS	Conditions
800-1,200	Ideal for wading and floating
1,200-1,800	Fishable, faster current
1,800-2,500	High but manageable
2,500+	Difficult, typically runoff conditions

Access Points:

• Lyons Bridge FAS: Upper float put-in, prime salmonfly water
• McAtee Bridge FAS: 19 miles south of Ennis
• Varney Bridge FAS: Primary mid-river access, excellent wade fishing
• Eight Mile FAS: West bank access between Varney and Ennis

Float Sections:

Section	Distance	Float Time	Notes
Lyons Bridge to Windy Point	6.2 miles	3-4 hours	Fast water, upper section
Lyons Bridge to McAtee Bridge	15.3 miles	Full day	Long float, pack lunch
McAtee to Varney	~9 miles	Full day	Most popular section
Varney to Ennis	~10 miles	Full day	Watch for Spring Creek Channel diversion

Hazard: One mile below Varney Bridge, the Spring Creek Channel splits from the main river. This channel has a diversion dam requiring portage at low flows. Stay right (main channel) unless you're prepared to portage.

Tactics: The Madison is big water. Most anglers fish from drift boats, pounding the banks with big dries. The key is precision - your fly should land within 6 inches of the bank, under willows, tight to log jams. Mid-river gets less attention but can produce. Look for seams where fast water meets slow, especially below the many small islands.

Named Spots:

• $3 Bridge: Popular wade section near Ennis with braided channels
• Windy Point: Aptly named - bring windproof flies
• The Channels: Braided section below Varney with excellent pocket water

Conservation Note: Warming waters have reduced suitable Salmonfly habitat on the Madison by roughly 50% over recent decades. The hatch remains strong but may shift earlier and compress into a shorter window as climate patterns change.

Big Hole River

The Big Hole offers 110 miles of floatable water with Salmonflies hatching across roughly 80 miles. It's less crowded than the Madison and offers more diverse water types.

Timing: June 10 - July 1

• First bugs appear near Glen by June 10th
• Hatch works upstream through the canyon section
• Reaches East Bank area by late June

Progression: Moves roughly 3 miles per day in good conditions.

Flow Windows (USGS 06024540 - Maiden Rock):

CFS	Conditions
800-1,500	Ideal wading and floating
1,500-2,500	Higher but fishable
2,500-4,000	Floatable, limited wading
4,000+	High water, difficult fishing

Key Access Points (by river mile, upstream to downstream):

• East Bank (RM 95): Concrete ramp, upper float access
• Jerry Creek (RM 90): Above canyon section
• Dewey/George Grant (RM 57): Mid-canyon
• Maidenrock (RM 48): Gauge location, prime water
• Salmon Fly FAS (RM 38): Named for the hatch - good reason
• Glen (RM 25): Lower river, first bugs of the season

Why Fish the Big Hole: The canyon section between Jerry Creek and Maidenrock offers stunning scenery and excellent fishing with less boat traffic than the Madison. The river supports healthy populations of both rainbow and brown trout, with browns often reaching 18-22 inches.

Yellowstone River

The Yellowstone produces Montana's most dramatic Salmonfly fishing. The river's size and the abundance of large trout make for memorable days.

Timing: Late June through early August

• Bugs appear near Livingston around July 1st
• Progress upstream through Paradise Valley
• Reach Yellowstone National Park (LeHardy Rapids area) by early August

Progression: Moves roughly 2 miles per day on this large river system.

Flow Windows (USGS 06192500 - Livingston):

CFS	Conditions
2,000-4,000	Ideal float fishing
4,000-6,000	Higher but floatable
6,000-10,000	Technical floating, some fishing possible
10,000+	Dangerous, unfishable

Best Sections:

• Paradise Valley (Grey Owl to Mallard's Rest): The "Bird Float" - scenic, mellow water, excellent fishing
• Livingston Town Stretch: Highest rainbow counts on the river, walk-in access
• Yankee Jim Canyon: Technical Class III water, cutthroat and rainbow trout

Access:

• Grey Owl FAS: Upper Paradise Valley put-in
• Mallard's Rest FAS: Popular take-out, entrance relocated after 2022 flood
• Pine Creek FAS: Good ramp, ample parking
• Carter's Bridge FAS: Rock beach launch, wade access

Note: The Yellowstone is the longest undammed river in the lower 48. Its flows depend entirely on snowmelt, making timing more variable than dam-controlled tailwaters.

Rock Creek

Rock Creek produces Montana's earliest major Salmonfly hatch and is a favorite among Missoula locals for that reason.

Timing: First week of June through June 10th

• Hatch begins where the river exits the canyon and joins the Clark Fork near Clinton
• One of the fastest-clearing rivers after runoff
• Water temps: Look for 52-54°F readings, typically reaches this 7-10 days before the Madison

Flow Windows (No USGS gauge - estimate from nearby Clark Fork):

CFS	Conditions
400-800	Ideal wade fishing
800-1,200	Fishable but pushy
1,200+	High, difficult wading

Why It Matters: When the Madison and Big Hole are still running high and off-color, Rock Creek often clears first. Savvy anglers start their Salmonfly season here, then follow the hatch east as other rivers come into shape.

Key Access Points (Rock Creek Road, south to north):

• Hogback Campground (Mile 14): Good pocket water, early clearing
• Bitterroot Flat (Mile 10): Wider section, easier wading
• Norton Campground (Mile 5): Lower river, warmest water, bugs appear first
• Valley of the Moon (Mile 2): Near confluence with Clark Fork

Local Knowledge: The section between Miles 8-12 holds the best combination of insect density and fish size. The river narrows through a mini-canyon here with excellent pocket water. Parking is limited - arrive early.

Clark Fork River

The Clark Fork near Missoula offers overlooked Salmonfly fishing, especially for anglers who can't make it to the Madison.

Timing: Late May - June 30

• Bugs appear in the Missoula area by late May
• Hatch works upstream from Rock Creek confluence toward Garrison

Best Sections:

• Alberton Gorge: Technical floating, excellent fishing, Class II-III rapids
• Harper's Bridge to Schwartz Creek: More accessible, good wade fishing

Why Fish It: Less crowded than the famous waters. The Clark Fork below Missoula holds surprisingly good numbers of trout, and during Salmonfly season, they're actively feeding.

Smith River

The Smith River offers a unique Salmonfly experience - you can only access much of it via multi-day float trip through a stunning limestone canyon.

Timing: Mid-May to early July (part of Montana's 6-week window)

• Permit required for overnight camping (lottery system)
• Salmonflies are active throughout the 59-mile float

The Experience: The Smith is one of North America's premier "big bug" rivers. The canyon provides shelter from wind and creates ideal Salmonfly habitat. The trade-off is access - you need a permit or must time a day float carefully.

Permit Information:

• Apply through Montana FWP lottery (opens January, closes mid-February)
• Permits cover launches March 1 - July 15
• Daily fee: $50/person for non-residents
• Very competitive: roughly 6,000+ applications for ~1,200 permits

Alternative: Outfitters hold commercial permits. Booking a guided trip bypasses the lottery but costs $2,000-3,500 for a 4-5 day trip.

Idaho

Henry's Fork of the Snake River

The Henry's Fork typically produces the earliest Salmonfly hatch in the Western U.S., starting around Memorial Day weekend.

Timing: Mid to late May through first week of June

• Water temperature trigger: 54°F
• Hatch works upstream from Ashton toward Box Canyon
• Golden Stoneflies follow about a week later

Key Sections:

• Box Canyon: Renowned for large rainbows, technical wading
• Below Ashton: More accessible, good float water

Tactics: The Henry's Fork is technical water. Even during the Salmonfly hatch, fish can be selective. Smaller imitations (sizes 6-8) often outfish exact-size patterns. The river also sees significant fishing pressure during this window.

Note: The Henry's Fork Foundation provides excellent resources for planning trips and understanding current conditions.

South Fork of the Snake River

The South Fork offers excellent Salmonfly fishing with less pressure than the Henry's Fork.

Timing: Late June to early July

• Water temperature trigger: 54°F (magic range 55-56°F)
• Starts in lower, warmer stretches
• Moves upstream roughly 4 miles per day

Duration: Can run anywhere from a few days to several weeks depending on flow stability. Stable flows produce longer, more consistent hatches.

Extended Fishing: Trout continue eating Salmonfly imitations for a full week after the actual flies stop hatching. The fish develop a search image and remain eager.

Upper Salmon River

The "River of No Return" offers remote Salmonfly fishing in stunning wilderness.

Timing: Mid-June through July

• Typical fly sizes: 4-8
• Hatch begins in lower reaches and moves upstream

Character: Remote, less crowded, big water. The Salmon offers adventure alongside the fishing. Golden Stoneflies follow 1-2 weeks after Salmonflies with overlap.

Oregon

Deschutes River

The Deschutes produces Oregon's most consistent Salmonfly hatch, drawing anglers from across the Pacific Northwest.

Timing: Mid-May through mid-June (most robust May 5-15)

• Water temperature trigger: 54-55°F
• Pre-hatch nymph activity: 10-14 days before surface emergence

Important: Dam release schedule changes (beginning in 2010) shifted the hatch earlier. Traditional timing (mid-May) has moved to early May in many years. Check recent reports.

Hatch Sequence:

1. Salmonflies emerge first
2. Golden Stoneflies follow about a week later
3. Yellow Sallies appear in June

Flow Information: The Deschutes is dam-controlled, providing more consistent flows than freestone rivers.

CFS	Conditions
3,640-7,000	Very fishable
7,000+	Limited to bank fishing

Tactics: The Deschutes sees the most fishing pressure of the year during Salmonfly season. Anglers who fish slightly behind the hatch (downstream of peak activity) or who target less-pressured side channels often have better success.

Pre-Hatch Nymphing: The 10-14 day pre-emergence window offers exceptional nymph fishing. Large stonefly nymphs migrate toward banks in huge numbers. Fish tight to the bank or directly below fast, oxygenated riffles.

Colorado

Upper Colorado River

The Colorado River between Dotsero and State Bridge produces Colorado's most accessible Salmonfly fishing, drawing anglers from the Front Range and beyond.

Timing: May 15 - June 30 (peak typically early June)

• Hatch moves upstream from Dotsero through State Bridge
• Typical fly sizes: 4-6
• Water temp trigger: 54-56°F

Flow Windows (USGS 09058000 - Colorado River near Kremmling):

CFS	Conditions
800-1,500	Ideal - excellent wading and floating
1,500-2,500	Higher but fishable
2,500-4,000	Float only, limited wading
4,000+	Runoff, difficult fishing

Key Access Points:

• Dotsero Put-In: Lower river, warmest water, bugs appear first
• Catamount Bridge: Mid-river access, good wade fishing
• State Bridge: Upper access, later in the hatch progression
• Pumphouse Recreation Site: Popular put-in for float trips

Float Sections:

Section	Distance	Notes
Pumphouse to Radium	14 miles	Full day, Class II-III rapids
Radium to State Bridge	8 miles	Half day, mellower water
State Bridge to Dotsero	30+ miles	Multi-day, remote

Local Knowledge: The section below State Bridge through the Burns area offers the best combination of insect density and reduced pressure. Most anglers crowd the Pumphouse to Radium stretch.

Gunnison River (Black Canyon)

The Gunnison in the Black Canyon produces monster Salmonflies and trophy trout in terrain that filters out casual anglers.

Timing: June, with peak emergence lasting 3-7 days per river section

Access Reality: This isn't casual fishing. Reaching the river requires:

• Hiking down steep, unmaintained routes (1,800-2,000 ft elevation loss)
• Scrambling over talus and through poison ivy
• Carrying all gear including waders
• Being prepared for no cell service and difficult evacuation

Popular Access Routes:

• Gunnison Route: Most accessible, still demanding
• Tomichi Route: Moderate difficulty
• Warner Route: Longer but more gradual
• SOB Draw: Experts only

Why Bother: Trophy browns in the 20-24" range are common. Fish see fewer anglers here than anywhere else in Colorado. During Salmonfly emergence, surface action can be incredible, and you might have a mile of river to yourself.

Permit: Free wilderness permit required. Self-register at South Rim visitor center.

Roaring Fork River

The Roaring Fork offers more accessible Colorado Salmonfly fishing, especially around Basalt and Carbondale.

Timing: Late May - mid-June

• Hatch appears in lower stretches first (near Carbondale)
• Works upstream toward Aspen

Access: Good public access at multiple points. Less demanding than the Gunnison but also more crowded.

Wyoming

North Platte River (Miracle Mile and Grey Reef)

Wyoming's best Salmonfly fishing happens on the North Platte, particularly in the tailwater sections.

Timing: Mid-June through early July

• Miracle Mile section sees bugs first
• Grey Reef follows 1-2 weeks later

Flow Information: Dam-controlled, providing more predictable conditions than freestone rivers.

Why Fish It: Less crowded than Montana options. The North Platte holds impressive numbers of large trout, and Salmonfly season coincides with excellent overall fishing conditions.

Tactics and Techniques

Time of Day: When Salmonflies Move

Understanding the daily rhythm of Salmonfly activity will put more fish in your net:

Early Morning (5am-9am): Prime time. Salmonflies that emerged overnight are warming up in bankside willows. As sun hits the water, they become active and start falling in. Trout are hungry after the night. This is your best window.

Mid-Morning to Early Afternoon (9am-2pm): Activity peaks, then tapers. Bugs are flying and laying eggs. Surface action can be frantic but fish may become selective or simply full. Good nymphing as well.

Late Afternoon (2pm-6pm): Female Salmonflies return to lay eggs, creating a secondary surface activity window. Often less crowded than morning.

Evening (after 6pm): Activity drops as temperatures cool. Can still be productive if bugs are on the water.

The Reality: On the best days, surface action runs all day. On tough days, you might have just a two-hour window in the morning. Flexibility matters.

The Dry-Dropper Approach

Here's a setup that consistently produces when other anglers struggle:

Primary dry: Large Salmonfly pattern (sizes 4-6) - Chubby Chernobyl or Stimulator Dropper: Rubber-leg stonefly nymph (sizes 8-10), 18-24" below dry Tippet: 2X or 3X fluorocarbon

Why it works: For every trout that eats a Salmonfly off the surface, ten more are eating nymphs below. The dry-dropper covers both opportunities. On a recent Madison float, my partner stuck with a single dry and landed 8 fish. I ran a dropper and landed 23.

Dry Fly Fishing

Presentation varies daily. Some days fish want dead-drift presentations. Others, they respond to aggressive twitching that imitates struggling or egg-laying adults. Experiment.

Work the banks. Salmonflies congregate in streamside willows and vegetation. Fish hold tight to banks waiting for bugs to fall. Your cast should land within inches of the bank, not feet.

Keep moving. "100 spots with 1 cast beats 1 spot with 100 casts." Your first cast into new water is most likely to produce. After 3-4 drifts without a take, move on.

Size down. Many anglers fish flies that match the actual insect size (2.5-3 inches). But experienced guides often recommend sizes 8-10. Trout see hundreds of real bugs and can become suspicious of perfect imitations. Smaller patterns sometimes trigger more strikes.

Nymph Fishing

Pre-hatch period (10-14 days before emergence): Fish large stonefly nymphs tight to banks and below oxygenated riffles. The nymph migration puts huge numbers of big insects in the drift. Standard indicator rigs with split shot work well.

During the hatch: Continue nymph fishing even when adults are present. Most trout food comes from below the surface. Target slower holding water where trout can pick off nymphs without fighting heavy current.

Rigging:

• Heavier tippet: 2X-3X (fish aren't leader shy in high, off-color water)
• Short, stiff-butt leaders: Turn over heavy flies better
• Weight: Split shot or weighted flies to get down quickly

When to Fish (and When Not To)

Best timing:

• 10-14 days before peak: Excellent nymph fishing, uncrowded
• 2-3 days after peak: Trout are hungry again after gorging, eager for one more meal

Worst timing:

• Peak of the hatch: Fish are often too full to eat. They've gorged on real insects and may spend days digesting. Nothing more frustrating than fishing through hundreds of bugs with no takers.

Position strategy:

• Fish ahead of the hatch: Trout seeing Salmonflies for the first time are eager
• Fish behind the hatch: After peak passes, fish are hungry and looking for more

Switching Patterns

When refusals increase, consider:

1. Size down: Go from #4 to #8
2. Switch to Golden Stone patterns: Fish get wise to the big orange bugs
3. Try smaller attractors: A #12 Stimulator or Royal Wulff can trigger strikes when Salmonfly patterns fail

Trout that have seen hundreds of Salmonflies may actually prefer something different.

River-Specific Tactics

Different rivers require different approaches:

Madison River:

• Pound the banks from a drift boat - precision casting is everything
• Focus on willows, log jams, and undercut banks
• Mid-river seams below islands often hold fish that see less pressure
• When the wind kicks up (it will), switch to heavier foam patterns

Big Hole River:

• More varied structure than the Madison - boulders, deep pools, pocket water
• The canyon section fishes well for waders
• Swing flies through slower runs at the tail of pools
• Browns tend to hold tighter to structure; rainbows more willing to move

Yellowstone River:

• Big water, big fish - use heavier tippet (2X)
• The fastest current often isn't the best water
• Look for inside bends, back eddies, and softer seams
• Cutthroat in upper sections are often more aggressive than browns below

Deschutes River:

• Technical water with educated fish - smaller patterns often work better
• Pre-hatch nymphing is exceptional here
• Fish behind the hatch - trout get wise to the big orange bugs quickly
• Side channels and less-pressured water are worth seeking out

Henry's Fork:

• The most technical Salmonfly water in the West
• Dead-drift presentations often outfish aggressive twitching
• Size down - these fish see a lot of flies
• Early morning before the parade of drift boats is your best window

Fly Patterns

Dry Flies

Classic Patterns:

Pattern	Size	Notes
Sofa Pillow	4-6	The original, Pat Barnes design, orange body
Improved Sofa Pillow	4-6	Elk/deer hair wing, palmered hackle
Stimulator (Orange)	4-8	Randall Kaufmann design, versatile
Chubby Chernobyl	6-8	Foam body for high flotation
Morrish Fluttering Stone	6	Excellent action on water
Henry's Fork Salmonfly	6	Developed for technical water

Selection Notes:

• Foam patterns float better in rough water and are easier to see
• Heavily hackled patterns can be skittered to imitate egg-laying females
• Have multiple sizes available - what works one day may fail the next

Nymphs

Pattern	Size	Notes
Pat's Rubber Legs	6-8	Black and orange, Montana classic
Bitch Creek Nymph	4-8	Heavy, good in fast water
Kaufmann Black Stone	6-10	Imitative style
Box Canyon Stone	6-8	Simple, effective
Girdle Bug	4-8	Rubber legs, versatile

Nymph Strategy: Carry three sizes to represent different year-classes of nymphs. Use heavier, impressionistic patterns in fast, deep water. Switch to lighter, more imitative flies in slower margins.

Gear Recommendations

Rod Selection

Minimum: 5-weight, 9-foot Ideal: 6-weight, 9-foot

Why heavier? Large Salmonfly patterns are wind-resistant. A 6-weight punches them into tight spots against the bank and handles the heavier tippets required for high water conditions.

Action: Medium-fast to fast. You need authority to cast big bugs and turn them over in wind.

Line and Leader

Line: Weight-forward floating, matched to rod weight

Leader Setup:

• Short and heavy (7.5', 2X-3X): For tight casting under overhanging willows
• Longer (9-12', 3X): For open water with drag-free drifts

Tippet: Never go lighter than 3X during Salmonfly season. Fish aren't leader shy in high, off-color water. Heavier tippet helps recover flies from bankside brush.

Reel

Any reel with a solid disc drag matched to your rod weight. Trout during the Salmonfly hatch fight hard and run far.

Timing Your Trip

Flexibility Is Essential

The single most important factor in successful Salmonfly fishing is flexibility. The hatch timing varies 1-2 weeks year to year based on:

• Snowpack and runoff timing
• Spring weather patterns
• Day-to-day temperature fluctuations

Best approach:

1. Plan a trip during the typical window
2. Build in extra days if possible
3. Be prepared to drive to where the bugs are
4. Call local fly shops for real-time reports

Tracking the Hatch

Water temperature is your primary indicator. Monitor temps on RiverReports or use a stream thermometer. When temps reach 54-56°F, emergence is imminent.

Call local fly shops. Shops in Ennis, Craig, West Yellowstone, and other gateway towns track the hatch daily. A quick phone call can save you from fishing the wrong section.

Be prepared to move. If you're on the Madison and the hatch hasn't arrived, consider driving to the Big Hole or Yellowstone where conditions might be better.

Using River Gauges

RiverReports helps you monitor conditions across multiple rivers:

River	USGS Gauge	Target Temp
Madison	06040000 (Cameron)	54-58°F
Big Hole	06024540 (Maiden Rock)	54-58°F
Yellowstone	06192500 (Livingston)	54-58°F
Deschutes	14092500 (Moody)	54-58°F

Watch for:

• Rising temps approaching 54°F: Hatch is coming
• Stable temps in the 55-58°F range: Active emergence
• Temps above 60°F: Hatch has likely moved upstream

Common Mistakes

Every angler who has chased this hatch has made these errors. Learn from our mistakes.

Setting the Hook Too Fast

Salmonflies are large. It takes time for a trout to fully commit and turn down with the fly. If you set immediately on the rise, you'll pull the fly out of the fish's mouth.

The first time I fished the Madison Salmonfly hatch, I missed five fish in a row before my guide grabbed my arm mid-set and said "Wait for it." Pause a beat after seeing the rise. Some anglers say "God save the Queen" before setting. Others simply wait until they feel the weight of the fish. Whatever works - just slow down.

Fishing the Peak

The hatch looks spectacular at its peak, but fishing is often worst. Trout gorge themselves and stop eating for days.

I once drove 12 hours to hit the peak of the Big Hole hatch. Bugs were everywhere - coating the willows, flying overhead, carpeting the water. And the fish? Stuffed. I threw perfect drifts to rising fish for two days and caught exactly three trout. The guys who arrived three days later, after the peak had passed, crushed it. Lesson learned: better to fish the edges - early (before peak) or late (2-3 days after).

Staying in One Spot

Your first cast into new water is the most likely to produce. Salmonfly fishing rewards covering water, not camping on one hole.

Using Light Tippet

Trout aren't leader shy during Salmonfly season. The water is often high and off-color. Use 2X-3X tippet - it helps land fish quickly (better for the trout) and recover flies from brush.

Ignoring Nymphs

Even during heavy surface activity, nymph fishing often produces more fish. The dry-dropper approach covers both options without sacrificing much.

Only Fishing Banks

Salmonflies congregate in bankside willows, so that's where most anglers focus. But trout also hold in deeper mid-river runs. Don't ignore the rest of the water.

Conservation Concerns

Salmonfly populations are indicators of river health. They require cold, clean, well-oxygenated water. Warming temperatures are shrinking suitable habitat on many rivers.

The Madison River has lost roughly 50% of suitable Salmonfly habitat over recent decades. Climate models predict further declines.

What this means for anglers:

• Hatches may compress into shorter windows
• Timing may shift earlier in the season
• High-elevation reaches may become more important

How to help:

• Practice catch-and-release
• Stop fishing when water temps exceed 68°F
• Support cold-water conservation organizations
• Follow Hoot Owl restrictions

Licenses and Regulations

Salmonfly season often spans multiple states. Here's what you need:

Montana

License Type	Non-Resident Cost (2025)
1-Day	$31.50
Each Additional Day	$14.00
5-Day	$73.50
Season	$117.50
Conservation License (required)	$10.00
AIS Prevention Pass (required, 16+)	$7.50

Total for 1 day: $49 | Total for season: $135

Purchase online at Montana FWP or at any fly shop.

Key Regulations:

• Hoot Owl restrictions may close fishing 2pm-midnight when water temps exceed 73°F for three consecutive days
• Check current restrictions before fishing during hot weather
• Most rivers allow catch-and-release with single barbless hooks

Idaho

License Type	Non-Resident Cost (2025)
1-Day	$18.75
3-Day	$43.75
Season	$113.75

Purchase at Idaho Fish and Game.

Oregon

License Type	Non-Resident Cost (2025)
1-Day	$28.50
3-Day	$43.50
Annual	$120.00

Purchase at Oregon DFW.

Colorado

License Type	Non-Resident Cost (2025)
1-Day	$21.08
5-Day	$36.08
Annual	$111.23

Purchase at Colorado Parks & Wildlife.

Wyoming

License Type	Non-Resident Cost (2025)
1-Day	$16.00
5-Day	$45.00
Annual	$102.00

Purchase at Wyoming Game & Fish.

Lodging and Base Camps

Salmonfly season fills up fast. Book 2-3 months in advance for peak dates.

Montana

Ennis (Madison River)

• The Sportsman's Lodge: $150-250/night, walking distance to river
• El Western Cabins: $120-180/night, rustic but clean
• Camping: Ennis FAS campground (free, first-come)

Livingston (Yellowstone River)

• Murray Hotel: Historic downtown, $150-250/night
• Yellowstone Pioneer Lodge: $100-150/night, basic but functional
• Camping: Mallard's Rest FAS (free)

Dillon (Big Hole River)

• Sundowner Motel: $80-120/night, fisherman-friendly
• Beaverhead Anglers Lodge: $150-200/night, guide service available
• Camping: Multiple FAS sites along the river (free)

Craig (Missouri River)

• Craig Montana Cabin Rentals: $150-250/night
• Land of Giants Motel: Basic, $80-120/night
• Limited options - book early or stay in Helena (45 min)

Idaho

Island Park/Last Chance (Henry's Fork)

• Henry's Fork Lodge: Premier option, $400+/night (includes meals)
• Angler's Lodge: $150-200/night
• Camping: Riverside Campground, Buffalo Run

Oregon

Maupin (Deschutes River)

• Imperial River Company: $100-150/night
• Oasis Resort: $80-120/night
• Camping: BLM sites along the river, Maupin City Park

Guide Services and Outfitters

Hiring a guide during Salmonfly season is worth serious consideration. Good guides know exactly where the hatch is on any given day and can position you for success.

Montana

Madison River:

• Blue Ribbon Flies (West Yellowstone): 406-646-7642 | $650/day
• Madison River Fishing Company (Ennis): 406-682-4293 | $625/day
• The Tackle Shop (Ennis): 406-682-4263 | $600/day

Big Hole River:

• Sunrise Fly Shop (Melrose): 406-835-3474 | $600/day
• Frontier Anglers (Dillon): 406-683-5276 | $575/day

Yellowstone River:

• Montana Angling Company (Livingston): 406-222-1673 | $650/day
• Anderson's Yellowstone Angler (Livingston): 406-222-7130 | $625/day

Missouri River:

• Headhunters Fly Shop (Craig): 406-235-3447 | $650/day
• Montana River Outfitters (Great Falls): 406-761-1677 | $625/day

Idaho

Henry's Fork:

• Henry's Fork Anglers (Last Chance): 208-558-7525 | $600/day
• TroutHunter (Island Park): 208-558-9900 | $650/day

Oregon

Deschutes:

• Deschutes Angler (Maupin): 541-395-2565 | $550/day
• The Fly Fisher's Place (Sisters): 541-549-3474 | $500/day

Booking Tips:

• Book 3-6 months in advance for peak Salmonfly dates
• Ask guides specifically about Salmonfly timing - they track it daily
• Half-day trips are available but full days maximize your hatch window

Safety and Hazards

Salmonfly season coincides with some of the year's most challenging conditions.

High Water and Fast Current

Freestone rivers run high and fast during Salmonfly season. Snowmelt is still coming off the mountains.

• Check flows before wading. Use RiverReports and know the fishable windows
• Use a wading staff. Essential in swift current
• Felt soles provide better grip than rubber on slippery rocks
• Wade with a partner when possible
• If you fall, don't fight the current. Float on your back, feet downstream, work toward shore

Cold Water

Even in June, Western rivers run 45-58°F. Extended immersion causes hypothermia.

• Wear waders, not wet wade
• Carry a dry bag with extra layers
• Know the signs of hypothermia: shivering, confusion, fatigue

Heat and Sun

Late June can bring 90°F+ temperatures.

• Start early (5am launch is common)
• Carry 2+ liters of water per person
• Wear sun protection - reflected glare off water intensifies exposure
• Watch for heat exhaustion, especially while wading in waders

Wildlife

Rattlesnakes: Present along many Western rivers, especially in rocky terrain and sage flats. Watch where you step, particularly around access points and when crossing talus.

Bears: Grizzly bears inhabit the Greater Yellowstone Ecosystem. Carry bear spray when fishing in Montana and Idaho.

Ticks: Active in June. Check yourself after fishing, especially in tall grass areas.

Weather

Afternoon thunderstorms are common. Lightning poses a serious danger on open water.

• Watch the sky - get off the river when storms approach
• Plan to be off the water by 2pm during unstable weather
• Bring rain gear even on sunny mornings

Planning Checklist

2-3 Months Before:

• Book lodging (fills up fast)
• Book guided trips if desired
• Purchase fishing licenses
• Request time off work - flexibility helps

1 Week Before:

• Call local fly shops for current hatch reports
• Check flows and temps on RiverReports
• Monitor weather forecasts
• Tie or buy appropriate patterns (dries and nymphs)

Gear Essentials:

• 6-weight rod with floating line
• Leaders in 2X and 3X (multiple spools)
• Salmonfly dries in sizes 4-8 (at least 6 per size)
• Salmonfly nymphs in sizes 6-10
• Golden Stone patterns (for backup)
• Strike indicators and split shot
• Polarized sunglasses
• Rain jacket
• Wading staff
• Bear spray (Montana/Idaho)
• Sun protection

On the Water:

• Monitor water temperature throughout the day
• Start early (bugs most active morning and evening)
• Cover water - don't camp on one spot
• Try dry-dropper setups
• Switch patterns when refusals increase
• Stay hydrated
• Watch the weather

Using RiverReports

Track Salmonfly conditions across multiple rivers:

River	USGS Gauge	What to Watch
Madison	06040000 (Cameron)	Temps reaching 54-58°F, flows under 2,000 CFS
Big Hole	06024540 (Maiden Rock)	Temps 54-58°F, flows under 2,500 CFS
Yellowstone	06192500 (Livingston)	Temps 54-58°F, flows under 6,000 CFS
Deschutes	14092500 (Moody)	Temps 54-58°F, flows under 7,000 CFS
Upper Colorado	09058000 (Kremmling)	Temps 54-58°F, flows under 2,500 CFS

Pro Tip: Compare temps across multiple rivers. If the Madison is at 60°F (hatch passed), check the Big Hole or upper Yellowstone where cooler temps might mean active bugs.

Download the RiverReports app for mobile access while on the road chasing the hatch.

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