Montana ·
Bighorn River Fly Fishing Report - August 16, 2026

BIGHORN RIVER
ReportAUG 16 — 23, 2026
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Flow
—CFS
🌡️
Water Temp
—
☀️
Weather
55–83°F
Partly Cloudy
💧
Clarity
Clear
Check post-storm
Live gauge data is unavailable today, but recent reports put flows around 1,000–1,500 cfs with clear water below Yellowtail Dam — classic tailwater summer conditions. Expect warm afternoon air temps near 83°F with light winds; a slight storm chance Sunday night could briefly improve dry-fly action.
What's Working — Hot Flies

Parachute - Blue Wing Olive #22
#22

Corn-fed Caddis (CDC) Tan #20
#20

Corn-fed Caddis (CDC) Peacock #18
#18

Tungsten Split Case Nymph - PMD #20
#20

Tungsten Tailwater Sowbug - Rainbow #10
#10

Tailwater Sowbug - Rainbow #10
#10

Black Zebra Midge(TBH) #20
#20

Pheasant Tail Tungsten #20
#20

Egan's Frenchie #12
#12

Bionic Hopper - Tan #12
#12

Juju Baetis Tungsten #22
#22

Coffey's CH Sparkle Minnow Sculpin #6
#6
Hatch Chart
| Insect | Size | Activity | Prime Time |
|---|---|---|---|
| Trico | 20-24 | Heavy | 6:30 AM - 9:30 AM |
| PMD | 16-20 | Moderate | 10 AM - 1 PM |
| Black Caddis | 16-18 | Heavy | 11 AM - 3 PM |
| Tan Caddis | 16-20 | Moderate | 1 PM - 5 PM |
| Blue-Winged Olive | 20-22 | Light | 4 PM - 7 PM |
| Midge | 20-24 | Moderate | 7 AM - 10 AM |
Best Time Window
- 6:30 AM - 9:30 AM: Prime Trico spinner fall and midge hatch — target flat tailouts and slow runs with dry flies and shallow nymphs.
- 10 AM - 1 PM: PMD and black caddis overlap — work riffles and seams with CDC caddis dries or a PMD split-case nymph just sub-surface.
- 4 PM - 7 PM: Afternoon hopper action along grassy banks transitions to a late BWO window — stay mobile and match what fish are keying on.
Guide's Tip
From the benchWith sunny skies and warm afternoon temps, your best dry-fly shots will be early — get on the water by 6:30 AM to intercept the Trico spinner fall in the flat tailouts before the sun gets high. Once the heat builds midday, drop down to a single tungsten sowbug or Frenchie and work the deeper slots with a tight-line or indicator setup, keeping your fly within 6 inches of the bottom. If you see fish rising to caddis along the riffles, switch to a CDC caddis pattern and focus on the seam edges where current speed changes — that's where fish will be holding and tipping up. The slight storm chance Sunday night could push a brief BWO hatch; be ready with a #22 Juju Baetis if clouds roll in and light goes flat.
Main Species
Brown Trout
Rainbow Trout
Mountain Whitefish
