Henry's Fork Fishing Forecast
The Henry's Fork is a spring-influenced Idaho trout stream where gin-clear water and picky fish reward patient drifts and fine tippet. Anglers target rainbow trout and brown trout across riffles, seams, and undercut banks in this region, with prime dry-fly and nymph windows typically clustering in late June through September. USGS gauge 13053000 tracks live flow and temperature for planning wade or float days. Local tactics angle: The Henry's Fork is one of the most technical trout streams in North America. The Railroad Ranch section is legendary for large, selective rainbows. TroutFishing pairs hatch timing with solunar windows so you know when to be on the water—not just where.
The Henry's Fork tailwater is sitting at moderate flows with a stable 55°F°F reading. Today's rating: 6/10. Top pick: a Stimulator.
Complex season — varies by section
Railroad Ranch section: catch-and-release Dec 1 to Fri before Mem Day. Other sections: Mem Day wknd - Nov 30 (6 trout). Some sections open year-round C&R
Forecast and on-page guide updated September 9, 2026 (UTC). Open the app for hourly conditions.
Today's Fishing Conditions
Good
Updated 7:48 PM
55°F
--
5 AM - 7 AM
Stimulator
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Quick Facts
Rainbow Trout and Brown Trout
spring creek
54°F - 64°F
What Makes the Henry's Fork Unique?
Signature hatch or window
BWO (Mayfly) is a headline hatch to watch in September. Peak activity often tracks 38–55°F water temps.
Distinctive access
Big Springs: Headwaters access. Crystal clear spring water.
Rules anglers miss
Artificial flies only in the Ranch section. No motors.
September Fishing Tactics
Primary Targets
Recommended Tactics
Fall fishing improves. BWOs return, browns become aggressive.
September Hatches
BWO
Mayfly
Blue Wing Olives hatch on overcast days, spring and fall
Caddis
Caddis
Evening caddis hatches prolific through summer
Hopper
Terrestrial
Grasshoppers effective on windy afternoons
Trico
Mayfly
Early morning spinner falls, tiny flies
October Caddis
Caddis
Large fall caddis, evening emergence
Year-Round Fishing Guide
| Month | Water Temp | Tactics |
|---|---|---|
| January | 32-38°F | Nymphing, Midges, Small Streamers |
| February | 32-40°F | Nymphing, Midges, Small Streamers |
| March | 36-46°F | Dry Flies, BWOs, Skwala |
| April | 42-52°F | Dry Flies, BWOs, Skwala |
| May | 48-58°F | Dry Flies, BWOs, Skwala |
| June | 54-64°F | Hoppers, Terrestrials, PMDs |
| July | 58-68°F | Hoppers, Terrestrials, PMDs |
| August | 60-70°F | Hoppers, Terrestrials, PMDs |
| September(Now) | 54-64°F | Streamers, BWOs, October Caddis |
| October | 46-56°F | Streamers, BWOs, October Caddis |
| November | 38-46°F | Streamers, BWOs, October Caddis |
| December | 32-40°F | Nymphing, Midges, Small Streamers |
Spawning Seasons
Please respect spawning fish and their redds. Avoid fishing over actively spawning trout.
Brown Trout
Spawn months: October, November
Night spawning common. Males become very dark with pronounced kype during spawn.
Rainbow Trout
Spawn months: March, April
Resident rainbow trout spawn in smaller tributaries and tend to build smaller redds than steelhead.
Access Points & Parking for Henry's Fork
Big Springs
Headwaters access. Crystal clear spring water.
Last Chance
Access to the famous Railroad Ranch section.
Osborne Bridge
Box Canyon access.
Ashton
Lower river access.
How to Fish Henry's Fork: Tips & Tactics
The Henry's Fork is one of the most technical trout streams in North America. The Railroad Ranch section is legendary for large, selective rainbows.
Best Times of Day
Prime season with green drakes in late June. PMDs hatch through July. Trico hatches bring morning action in August. Fish rise in predictable locations - learn the water and find your fish before casting.
Recommended Techniques
Match the hatch precisely and use light tippet. Observe feeding lanes and time your casts. Long, drag-free drifts are essential. The Last Chance Cripple pattern was developed for this water.
Water Conditions
Runoff can be challenging in spring. Focus on spring creek sections during high water. Optimal flows are 400-1,200 CFS on the Ranch.
Fly Selection
Green Drake and PMD patterns are essential. Trico and rusty spinner patterns for late summer. Last Chance Cripple is a must-have pattern.
When is the Best Time to Fish Henry's Fork?
Spring
Runoff can be challenging. Focus on spring creek sections.
Summer
Prime season with green drakes, PMDs, and Tricos. July-August is best.
Fall
October caddis and streamers. Brown trout move up from the reservoir.
Winter
Limited winter access. Some sections fish through mild weather.
Recommended Equipment for Henry's Fork
Rod
9-foot, 4 or 5-weight for most fishing.
Line
Floating line with long leaders.
Leader & Tippet
12-15 foot leaders, 5X-6X tippet.
Waders
Breathable waders. Cold spring water even in summer.
Essential Flies
Henry's Fork Fishing Regulations
Season
Open June through November. Check current dates.
Limits
Catch-and-release for rainbow trout in most sections.
Special Regulations
Artificial flies only in the Ranch section. No motors.
Bait Restrictions
Artificial flies only.
Notes
Check Idaho Fish and Game for current regulations.
Always verify current regulations with Idaho fish and wildlife agency before fishing. Regulations can change annually.
Fly Shops & Guides Near Henry's Fork
Local Fly Shops
- Henry's Fork Anglers - Last Chance
- TroutHunter - Island Park
- Last Chance Lodge
Guide Services
- Henry's Fork Anglers Guides
- TroutHunter Guide Service
- Mike Lawson's Guide Service
Optimal Fishing Conditions
Optimal Flow
400 - 1200 CFS
Best fishing conditions
Optimal Water Temperature
50° - 62°F
Ideal for active trout
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Henry's Fork — frequently asked questions
When is the best time to fish the Henry's Fork?
Fall fishing improves. BWOs return, browns become aggressive.
What flies should I bring to the Henry's Fork?
For the Henry's Fork (spring creek), carry: Green Drake, PMD, Rusty Spinner, Trico, Last Chance Cripple.
What water temperature is best for trout on the Henry's Fork?
On the Henry's Fork, trout hold between 50° and 62°F. The spring-fed source keeps temperatures remarkably stable.
Do I need a fishing license for the Henry's Fork?
Yes — you need a valid Idaho fishing license to fish the Henry's Fork. Local season: Open June through November. Check current dates.. Daily limit: Catch-and-release for rainbow trout in most sections..
What hatches should I watch for on the Henry's Fork in September?
BWO is the signature hatch on the Henry's Fork in September. Match size and adjust leader size to 5X-6X. The fish key in on the emergence during low-light hours, so plan to be on the water at first light.
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