Montana ·
Madison River Fly Fishing Report - May 31, 2026
MADISON RIVER
ReportMAY 31 — JUN 7, 2026
🌊
Flow
—CFS
🌡️
Water Temp
—
☀️
Weather
33–61°F
Light Rain Likely
💧
Clarity
Clear
Check post-storm
Real-time USGS gauge data is unavailable for this report; recent public reports (May 25) indicated ~736 cfs at Kirby Ranch with a rising trend and 45°F water temps. Expect unsettled, cool, and cloudy conditions through the weekend with mixed rain and snow — ideal for BWO hatches but watch for any bump in flows from snowmelt.
What's Working — Hot Flies
Tungsten Pat's Rubber Legs - Tan & Brown
#6
Olsen's Straggle Stone Brown Barbless
#12
Egan's Thread Frenchie Jig - Olive
#12
Blowtorch - Hare's Ear
#12
Juju Baetis Tungsten
#22
Olsen's Hare's Ear Blowtorch Barbless
#20
Parachute - Blue Wing Olive
#22
Corn-fed Caddis (CDC) Olive
#20
Egan's Silver Bullet - Baetis
#14
Coffey's CH Sparkle Minnow Sculpin
#6
Hatch Chart
| Insect | Size | Activity | Prime Time |
|---|---|---|---|
| Blue-Winged Olive (Baetis) | #18–22 | 🟢 Active | Midday–2:00 PM; overcast & rainy days best |
| Midge (Chironomid) | #20–24 | 🟢 Active | Morning & evening; slow pools and flats |
| Early Caddis | #16–18 | 🟡 Building | Afternoon as water temps warm |
| Skwala Stonefly | #8–10 | 🟡 Tapering | Warm afternoons, bankside water |
| Salmonfly (Pteronarcys) | #4–6 | 🔴 Approaching Fast | Late May–early June; triggers when flows drop & temps hit low 50s°F |
| Pale Morning Dun (PMD) | #16–20 | 🔴 Not Yet | Late June on most sections |
Best Time Window
- 11:00 AM – 2:00 PM: Prime BWO dry fly window, especially under the overcast and rainy skies forecast through Sunday
- 7:00 AM – 10:00 AM: Midge activity in slow pools and flats; streamer fishing productive in low light before the sun hits
- 4:00 PM – Dusk: Caddis building in the afternoons as water temps nudge upward; streamer swinging through deeper structure
Guide's Tip
From the benchWith a cool, unsettled weekend ahead — rain, possible snow Sunday, and highs only in the mid-50s — the BWO hatch is your best dry fly opportunity of the season. Watch for subtle sipping rises in the slower flats between 11 AM and 2 PM, drop to 5X or 6X fluorocarbon, and make a careful downstream presentation with a size 22 Parachute BWO. Keep a heavy nymph rig ready for the rest of the day: set your indicator deep, anchor with a Pat's Rubber Legs, and trail a Frenchie or Blowtorch Hare's Ear — fish are hugging the bottom and tucked into softer bank water to escape the heavier current. The Salmonfly hatch is closing in fast; when you start seeing big orange bugs crawling on streamside willows and boulders, it's time to pound the banks with a large foam pattern.
Main Species
Brown Trout
Rainbow Trout
Mountain Whitefish
