Henry's Fork
OptimalIdaho
Current Conditions
The Henry's Fork is running at 651 CFS — ideal conditions. Expect clear water and excellent dry fly opportunities.
Last updated: Oct 9, 2026, 10:15 AM from USGS gauge 13046000 (Henry's Fork near Island Park)
7-Day Flow Trend
Flow thresholds: Optimal 600–1200 CFS | Fishable to 2500 CFS | Marginal to 4000 CFS
About the Henry's Fork
The Henry's Fork of the Snake River is one of the most celebrated fly fishing rivers in the world. The Railroad Ranch section in Harriman State Park is the ultimate dry fly destination, with incredible Green Drake and PMD hatches over large, selective rainbows.
Hatch Chart
| Insect | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Green Drake Green Drake Dun #10-12 | ||||||||||||
Pale Morning Dun PMD Sparkle Dun #16 | ||||||||||||
Blue-Winged Olive BWO Parachute #18-20 | ||||||||||||
Caddis Elk Hair Caddis #14-16 | ||||||||||||
Callibaetis Callibaetis Spinner #14 | ||||||||||||
Hopper Dave's Hopper #8 |
Active Hatches — October
Patterns: BWO Parachute #18-20, Sparkle Dun #18
River Map
River Sections
Railroad Ranch (Harriman)
wade access651 CFS
The legendary flat water section in Harriman State Park. Sight-fishing to rising trout with delicate presentations.
Last Chance to Ashton
wade/float access94 CFS
Below the ranch with more varied water types. Excellent riffle-run fishing.
Guides on the Henry's Fork(8)
These fishing guides list the Henry's Fork as one of their home waters.
Henry's Fork Anglers
Island Park, Idaho
Trout Hunter
Idaho
Firehole Ranch
West Yellowstone, Montana
Teton Valley Lodge
Driggs, Montana
Henry's Fork Lodge
Island Park, Idaho
TroutHunter Lodge
Island Park, Idaho
Teton Springs Lodge
Victor, Idaho
Elk Creek Ranch
Island Park, Idaho
Frequently Asked Questions
What is the best time to fish the Henry's Fork?+
The Henry's Fork fishes well from spring through fall. Peak dry fly season is typically June through September. The best hatches occur during summer months with PMDs and caddis. Fall brings excellent streamer fishing and fewer crowds.
What flies work on the Henry's Fork in October?+
In October, the Henry's Fork sees Blue-Winged Olive activity. Top patterns include BWO Parachute #18-20. Always carry a selection of nymphs as well.
How many fishing guides operate on the Henry's Fork?+
Avonture lists 8 fishing guides who operate on the Henry's Fork. These guides offer local knowledge of hatches, access points, and current conditions that can significantly improve your experience.
What is the current flow on the Henry's Fork?+
The Henry's Fork's flow data is updated every 30 minutes from USGS gauge stations (waterdata.usgs.gov). Check the top of this page for current CFS readings, fishability status, and a 7-day flow trend chart. Optimal fishing flows are 600–1200 CFS.
What fish species are in the Henry's Fork?+
The Henry's Fork primarily holds wild brown trout and rainbow trout. Cutthroat trout may also be present in some sections. Fish sizes vary by section, with tailwater reaches typically holding larger fish.
Quick Conditions
Fishability Thresholds