Wade78/100
Wading is in play only where your chosen access has clear footing, legal entry, and no forced crossings.
All Idaho reports
Fly fishing report · West
Henry's Fork of the Snake River
Is Henry's Fork of the Snake River worth the trip today? Check flow, weather, hatches, access, and rules for Idaho before you go.
See the flow chart ↓Photo: Z3lvs Opens in a new tab. · CC0
Good day to fish?Latest river check
Good fishing
Yes. Fishing looks good.
78
Good fishing based on the verified flow and weather. No official live water-temperature reading is available. Carry a thermometer during warm weather and stop if the water is stressful for trout.
See update time and confidence
Live data checkHighHow much of the live flow, weather, and alert data came back.
Today's callMediumWater temperature not verified; do not use this score to clear warm-water risk.
Score calculated Aug 22, 2026, 10:45 PM MDTUsually checks again about every 45 minutes
Access choicesNo clear best mode
Wade and Float have the same top score. Use current access, footing, weather, and local rules to choose.
Bank / edgeNot recommended
This report does not recommend bank fishing on this reach.
Float78/100
A float is in play where this report supports boat access and wind, releases, and shuttle logistics are manageable.
Your plan
Today's Henry's Fork of the Snake River plan.
The Henry's Fork is not one simple report. Box Canyon, Last Chance, Harriman Ranch, Ashton, and St. Anthony all fish differently, so use the Island Park flow and confirm section-by-section rules before you commit.
- Check first
- Use the Island Park gauge for upper river and Ranch planning.
- Try
- Choose Box Canyon, Ranch, Ashton, or lower river before rigging.
- Leave when
- Skip or change reaches when Harriman Ranch dates or special rules are unclear, when releases make wading or floating unsafe, when wind defeats technical dry-fly fishing, or when crowding would force poor etiquette.
Live river check
What the river is doing
Check the latest flow and weather before you go. A quick change can make the river harder or less safe to fish.
Showing the latest stored river check while current readings load.
- Flow
- 711 cfs
- From the latest stored river check. Open the official source for the newest reading.
- Air now
- 61°F
Current NWS forecast period
- Next 24h high
- 75.0°F
NWS air forecast near
- Rain chance
- 38%
For this forecast period
This is an air forecast, not a river-temperature reading. Check the water with a stream thermometer before fishing in hot weather.
Latest stored weather check
Chance Light Rain
Chance Light Rain
- Wind
- 3 mph
- Weather checked
Recent flow chart is loading
The latest stored reading is shown above. Check the official source below if you need the newest value now.
More forecast and source details
National Weather Service
Henry's Fork Island Park forecast point
The National Weather Service forecast is temporarily unavailable.
Live data
Where these readings come from
RiverReports gauge: Henry's Fork near Island Park
How to fish it
How to fish Henry's Fork of the Snake River today.
The Henry's Fork is best when the reach, flow, hatch, and rules all line up. If one section is high, crowded, closed, or wind-hit, use another gauge and choose a different reach.
Stable upper flow
Good for Box Canyon nymphing and Ranch dry-fly planning when wind allows.
High release
Favor boats, edges, and heavy nymphs where legal. Avoid unsafe crossings.
Low clear Ranch water
Use long leaders, careful angles, and match the actual insect stage.
Windy meadow day
Shift to protected edges, Box Canyon, or a lower reach instead of forcing tiny dries.
Fishing words used on this page
- U.S. Geological Survey (USGS) gauge
- A USGS gauge is an official river station that measures flow or water height.
- Cubic feet per second (cfs)
- Cubic feet per second, or cfs, shows how much water passes the gauge each second.
- Technical fishing
- Technical fishing means the fish are hard to fool, so careful casts and natural drifts matter.
- Nymph
- A nymph is a young water insect. Anglers also use the word for a fly that copies it.
- Blue-winged olive (BWO)
- Blue-winged olives, or BWOs, are small mayflies that often hatch in cool or cloudy weather.
- Caddis
- Caddis are small water insects. The adults look a little like tiny moths.
- Emerger
- An emerger copies an insect as it rises from below the water toward the surface.
- Midge
- Midges are tiny flies and a common trout food, especially in cold water.
- Pale morning dun (PMD)
- Pale morning duns, or PMDs, are light-colored mayflies that often hatch in warmer months.
- Pocket water
- Pocket water is a small calm spot among rocks or fast current.
Why this call
Why this score
FlowUse caution
USGS shows 711 cfs. The flow has been stable over about 6 hours. USGS marks this reading provisional and may revise it. USGS records for this date (1933-2025, 93 readings) show a median near 963 cfs and the lower quartile near 764 cfs; today's flow is below normal for the date. This is below normal, so edge depth, temperature, and pressure matter.
SeasonHelps
Late summer: Terrestrials, tricos, morning spinner falls, and technical sight fishing become central.
WeatherHelps
The current NWS air forecast is about 61F, and the next 24-hour high reaches about 75F. Chance Light Rain.
Public alertsHelps
No active NWS alert was returned for this forecast point.
Fishing usefulnessHelps
Skip or change reaches when Harriman Ranch dates or special rules are unclear, when releases make wading or floating unsafe, when wind defeats technical dry-fly fishing, or when crowding would force poor etiquette.
Trip notes
Trip notes
Check these before you choose a reach.
Use the RiverReports Island Park chart and USGS 13042500 together. Stable releases make the best technical window. Sudden changes, heavy wind, or off-color water should move you to a different reach, safer bank, or another nearby river.
Skip or change reaches when Harriman Ranch dates or special rules are unclear, when releases make wading or floating unsafe, when wind defeats technical dry-fly fishing, or when crowding would force poor etiquette.
Start with the style of day: Box Canyon nymphs and streamers, Last Chance and Ranch dry-fly work, or a lower-river float. Then check access, rules, flows, and wind for that reach rather than relying on one river-wide plan.
If the Henry's Fork is windy, crowded, rule-sensitive, or off-color, compare the South Fork of the Snake, Silver Creek, or Madison River after checking current flows and rules.
What to try
Henry's Fork of the Snake River flies through the year.
Match the time of year, then let rising fish and current speed guide the next change.
SeasonWhat to look forFlies to try
Spring
What to look forMidges, BWOs, caddis
Early summer
What to look forSalmonflies, golden stones, PMDs, green drakes
Mid to late summerCurrent
What to look forTricos, callibaetis, terrestrials, caddis
Fall
What to look forBWOs, midges, October caddis
Each fly name opens its matching Fly Box guide.
Access and safety
Henry's Fork of the Snake River access and rules.
Use these places as starting points. Open the access link below and check posted signs before you park or enter. IDFG lists detailed Henry's Fork reach rules, including closed water, Harriman Ranch dates, fly-only/barbless sections, and no-bait/catch-and-release reaches.
Island Park and Box Canyon
Upper tailwater flow reference with faster pocket water and boat/wade options.
Last Chance and Harriman Ranch
Technical meadow water with seasonal and gear restrictions.
Ashton and Mesa Falls area
Middle-river planning with different water speed and access.
St. Anthony and lower Henry's Fork
Lower-river access and boat planning with separate gauge context.
Rules vary sharply by reach and date.
Wind can matter as much as flow on slow meadow water.
Private land and park rules make access checks essential.
Use multiple gauges if fishing far below Island Park.
River sources
Official Henry's Fork of the Snake River sources.
Official agencies and primary river operators come first. Secondary tools are labeled so you know what carries the most weight.
How this report was checked
How this report was checked
Reviewed byBlueStreamFly River Review Team
Trip guidance checked
What was checked: This Henry's Fork report is maintained from RiverReports and USGS flow data, Idaho Fish and Game reach rules, BLM Henrys Fork access information, Harriman State Park references, weather checks, and reach-specific trout planning guidance.
Live measurements and forecasts keep their provider timestamps. Rules, access, and trip guidance use the source-review date shown here. BlueStreamFly planning advice is editorial interpretation, not an agency notice.
First-hand experience: BlueStreamFly does not claim a first-hand visit or local field test for this report unless a real contributor is explicitly named and linked.
Rules and closures
Check what is allowed, where the rule applies, and whether the river is open.
Flow and weather
Check the latest river reading and forecast before you leave.
Access and land
Check public entry points, land rules, and seasonal access changes.
See all 6 checked sources
Rules and closures
Check what is allowed, where the rule applies, and whether the river is open.
What this source covers
Open the current rules and check the river section, season, and special limits.
Flow and weather
Check the latest river reading and forecast before you leave.
What this source covers
Open this page and check the latest safety advice before your trip.
What this source covers
Open this river reading to check the latest level, flow, and update time.
What this source covers
Open this river reading to check the latest level, flow, and update time.
Access and land
Check public entry points, land rules, and seasonal access changes.
What this source covers
Open the land or access page, then check signs before you park or enter.
What this source covers
Open the land or access page, then check signs before you park or enter.
Quick answers
Quick Henry's Fork of the Snake River answers.
Which Henry's Fork gauge should I use?
Use Island Park for upper river, Box Canyon, and Ranch planning. Check Ashton or St. Anthony if fishing lower reaches.
When does Harriman Ranch open?
Check IDFG each season. The Ranch has specific closure and fly-fishing-only/barbless language.
Is the Henry's Fork beginner friendly?
Some faster reaches are approachable, but Ranch dry-fly fishing can be very technical.
What should I check besides flow?
Wind, reach rules, access, weed growth, and the actual hatch stage matter.