Idaho ·
Henrys Fork Fly Fishing Report - September 20, 2026

HENRYS FORK
ReportSEP 20 — 27, 2026
🌊
Flow
—CFS
🌡️
Water Temp
—
☀️
Weather
34–70°F
Scattered Rain Showers
💧
Clarity
Clear
Check post-storm
Live USGS gauge data is unavailable for today, but recent web intel from September 13 reported flows near 1,150 cfs with clear water and good visibility — expect similar or slightly lower flows as the seasonal trend continues downward. Overnight rain showers may add a touch of color by morning, so check clarity before committing to a reach.
What's Working — Hot Flies

Parachute - Blue Wing Olive #22
#22

Carlson's Purple Haze (Poly Wing) #18
#18

Juju Baetis Tungsten #22
#22

Top Secret Baetis #16
#16

Olsen's Pheasant Tail Nymph Doppleganger Brown Barbless #24 - 20
#20

Tungsten Pat's Rubber Legs - Tan & Brown #6
#6

Bionic Hopper - Tan #12
#12

Bionic Ant 2.0 - Black #16
#16

Black Zebra Midge(TBH) #20
#20

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

Egan's Silver Bullet - Baetis #14
#14

Guides Choice Hare's Ear #18
#18
Hatch Chart
| Insect | Size | Activity | Prime Time |
|---|---|---|---|
| Blue-Winged Olive (Baetis) | #20-22 | Moderate | 11 AM - 2 PM |
| Mahogany Dun | #16-18 | Moderate | 12 PM - 3 PM |
| Midge | #20-22 | Light | 8 AM - 10 AM |
| Terrestrial (Ant) | #16 | Light | 1 PM - 4 PM |
| Grasshopper | #12 | Light | 12 PM - 3 PM |
| Caddis | #18-20 | Light | 4 PM - 6 PM |
Best Time Window
- 7 AM - 9 AM: Midge and early nymph window; high-stick rubber legs and zebra midges through the deeper runs before the sun hits the water.
- 11 AM - 2 PM: Prime BWO and Mahogany Dun hatch; switch to dry flies as fish begin rising in the flat, weedy meadow sections.
- 3 PM - 5:30 PM: Terrestrial and caddis hour; work hopper and ant patterns tight to the grassy banks while light holds on the water.
Guide's Tip
From the benchWith overnight rain showers possible, check water clarity at your first access point before rigging — if there's any off-color tinge, focus on the lower, slower flats where fish can see your fly longer. Once the sun climbs and the air warms toward midday, position yourself downstream of rising fish in the flat meadow sections and present your Mahogany or BWO dry with a pile cast to buy extra drag-free drift time. The clearest, most technical fish will be holding in the seams between weed beds, so keep your approach low and your shadow off the water. Afternoon sun on Monday promises the best dry-fly window of the weekend — plan your best water for then.
Main Species
Rainbow Trout
Brown Trout
Yellowstone Cutthroat Trout
