Montana ·
Blackfoot River Fly Fishing Report - October 4, 2026
BLACKFOOT RIVER
ReportOCT 4 — 11, 2026
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Flow
593CFS
Blackfoot River near Bonner MT
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Water Temp
53.1°F
Updated 2026-10-04
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Weather
40–82°F
Mostly Clear
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Clarity
Clear
Check post-storm
Flow is holding steady at 593 CFS (gauge height 2.1 ft) with crystal-clear water at 53.1°F — ideal fall conditions that are concentrating fish in deeper holding lies with structure and shade. Sunny skies and a high near 82°F today will push the best dry-fly action to morning and late afternoon.
What's Working — Hot Flies
Bionic Hopper - Tan #12
#12
Bionic Hopper - Purple #12
#12
Bionic Ant 2.0 - Black #16
#16
Bionic Ant 2.0 - Purple #16
#16
Corn-fed Caddis (CDC) Tan #20
#20
Parachute - Blue Wing Olive #22
#22
Top Secret Baetis #16
#16
Egan's Thread Frenchie Jig - Olive #12
#12
Soft Hackle Pheasant Tail Jig - Barbless #12
#12
Olsen's Straggle Stone Brown Barbless #12
#12
Tungsten Rainbow Warrior - Extra Heavy #14
#14
Coffey's CH Sparkle Minnow Sculpin #6
#6
Hatch Chart
| Insect | Size | Activity | Prime Time |
|---|---|---|---|
| October Caddis | #8-10 | Moderate | 3 PM - 6 PM |
| Mahogany Dun (Paraleptophlebia) | #16-18 | Moderate | 11 AM - 2 PM |
| Blue-Winged Olive (Baetis) | #20-22 | Light | 12 PM - 3 PM |
| Terrestrials (Ants, Hoppers) | #12-16 | Moderate | 10 AM - 4 PM |
| Midge | #20-22 | Light | 8 AM - 10 AM |
Best Time Window
- 7 AM - 10 AM: Pre-sun nymphing in deep boulder pockets and runs with heavy jig nymphs before fish push tight to structure.
- 11 AM - 2 PM: Mahogany Dun and BWO window in slower flats and tailouts; watch for subtle risers and match with small dries or soft hackles.
- 4 PM - 7 PM: Prime terrestrial and October Caddis hour — work hopper and ant patterns tight to shaded banks as afternoon light drops off the water.
Guide's Tip
From the benchWith 53°F water and a sunny high of 82°F, fish will be sluggish and deep during the midday heat — focus your nymphing in the 3- to 5-foot depth range along the shaded side of boulders and undercut banks. As afternoon shadows hit the water around 4 PM, switch to a hopper or October Caddis adult and work the grassy, willow-lined banks with a downstream reach cast, keeping your fly in the lane for a full 10-15 feet before picking up. Note that floating from the Weigh Station to I-90 is closed through October 31 — plan your float accordingly and treat the Weigh Station as your last takeout.
Main Species
Westslope Cutthroat Trout
Brown Trout
Rainbow Trout
