Colorado ·
Gunnison River Fly Fishing Report - September 20, 2026

GUNNISON RIVER
ReportSEP 20 — 27, 2026
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Flow
200CFS
GUNNISON RIVER NEAR GUNNISON, CO.
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Water Temp
57.6°F
Updated 2026-09-19
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Weather
30–71°F
Mostly Clear
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Clarity
Clear
Check post-storm
Flow is running at 200 CFS with a gauge height of 0.96 ft and water temps at 57.6°F — slightly elevated from early-September lows but still gin-clear, demanding precise presentations and fine tippet. Overnight lows near 32°F will slow the morning bite, but a sunny 69°F afternoon sets up a textbook fall dry-fly window.
What's Working — Hot Flies

Parachute - Blue Wing Olive #22
#22

Juju Baetis Tungsten #22
#22

Olsen's Quilldigon - Olive - Barbless #22 - 24
#22-24

Olsen's Hare's Ear Blowtorch Barbless #20 - 28
#20

Black Zebra Midge(TBH) #20
#20

Olsen's Peacock Blowtorch Barbless #22 - 24
#22-24

Roza's World Spain Perdigon Barbless #18 - 32
#18

Egan's Silver Bullet - Baetis #14
#14

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

Bionic Ant 2.0 - Black #16
#16

Egan's Frenchie #12
#12

Coffey's CH Sparkle Minnow Sculpin #6
#6
Hatch Chart
| Insect | Size | Activity | Prime Time |
|---|---|---|---|
| Blue-Winged Olive (Baetis) | 20-22 | Heavy | 11 AM - 3 PM |
| Midge | 20-24 | Moderate | 9 AM - 12 PM |
| Caddis | 16-20 | Light | 4 PM - 6 PM |
| PMD (Pale Morning Dun) | 18-20 | Light | 12 PM - 2 PM |
| Terrestrials (Ants) | 14-16 | Light | 1 PM - 4 PM |
Best Time Window
- 9 AM - 11 AM: Midge and early nymph bite as sun warms the water; work tailouts and flat seams with small nymphs.
- 11 AM - 2 PM: Prime BWO dry-fly window — fish the slow inside bends and flat water with a #22 Parachute BWO on 6X.
- 4 PM - 6 PM: Late caddis and terrestrial action along grassy banks; skate a CDC Caddis or dead-drift a Bionic Ant in the film.
Guide's Tip
From the benchWith 57.6°F water and overnight temps dropping to 32°F, the morning bite will be slow until the sun hits the water and warms things up — don't rush the river at dawn. Focus your nymphing in the 18-24 inch depth range along the seam edges of mid-river boulders from 9 AM onward, then transition to a dry fly as the BWO hatch fires between 11 AM and 2 PM. Use 6X fluorocarbon tippet on your dry flies — at 200 CFS the water is clear enough that fish will refuse anything heavier. In the afternoon, when WSW winds pick up to 15 mph with gusts to 25, move to sheltered canyon bends and fish terrestrials tight to the grass banks where the wind is blowing ants onto the surface.
Main Species
Brown Trout
Rainbow Trout
Mountain Whitefish
