Idaho
Henrys Fork near Island Park
Current River Rating
Fair · 52
Conditions are mixed. Review the details below before heading out.
Scores are model-specific and are not directly comparable across water types.
Partial water evidence · Low confidence
Should I Go?
Wait
Timing Outlook
This timing outlook is informational only; current river conditions remain Fair.
Why
- Very clear skies may make trout more cautious in shallow water.
- Water temperature is unavailable.
Favorable Factors
- Recent precipitation has been light.
- Light wind should make casting and boat control easier.
Timing Evidence
Dawn low light is favorable.
Current Readings
- Flow
- 1210 CFS
- Gage Height
- 4.53 ft
- Water Temperature
- Not available
- Observation Time
- Sep 5, 2026, 6:45 AM
Updated recently · USGS station 13042500 · Direct monitoring location
Readings from past 7 Days
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Historical readings are provided for context. Readings outside the current freshness window are not used to rate current conditions.
Better Nearby Options
Checking nearby StrikeTracks waters…
Preliminary guidance only. Always assess current weather, access, water depth, current speed, and your own ability before entering the river.
Changing Conditions Advisory
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Weather Near Gauge
Current Weather
Clear
Temperature
52°F
Feels like
46°F
Wind
6 mph NE
Wind gust
12 mph
Current precipitation
0.00 in
Updated
Sep 4, 2026, 11:15 PM
Recent Rainfall
Estimated precipitation near this gauge
Last 6 hours
0.00 in
Last 24 hours
0.00 in
Last 48 hours
0.00 in
Little recent rainfall near this river.
Next 24 Hours
Sat 2 AM
Clear
Temp 53°F
Chance 1%
Precip 0.00 in
Wind 7 mph
Sat 6 AM
Clear
Temp 45°F
Chance 1%
Precip 0.00 in
Wind 3 mph
Sat 10 AM
Clear
Temp 58°F
Chance 0%
Precip 0.00 in
Wind 4 mph
Sat 2 PM
Clear
Temp 72°F
Chance 0%
Precip 0.00 in
Wind 17 mph
Sat 6 PM
Clear
Temp 73°F
Chance 0%
Precip 0.00 in
Wind 11 mph
Sat 10 PM
Clear
Temp 57°F
Chance 0%
Precip 0.00 in
Wind 5 mph
Four-Day Forecast
Sat, Sep 5
Overcast
High 74°F / Low 43°F
Chance 2%
Precip 0.00 in
Max gust 30 mph
Sun, Sep 6
Drizzle
High 76°F / Low 48°F
Chance 37%
Precip 0.05 in
Max gust 27 mph
Mon, Sep 7
Showers
High 60°F / Low 47°F
Chance 85%
Precip 0.34 in
Max gust 33 mph
Weather and rainfall are estimated for this river's coordinates. Local conditions can vary, especially in mountainous terrain and during isolated storms.
Recent rainfall can influence river flow, but the timing and magnitude depend on watershed size, soil conditions, upstream reservoirs, and dam releases.
Weather data: Open-Meteo
Historical Flow
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Fishing Overview
Henrys Fork near Island Park, Idaho. Monitoring-Backed from USGS 13042500 (live discharge and stage). No live 00010. Distinct from Ashton 13046000.
Fishery Profile
Documented species you may encounter at Henrys Fork.
Species images are AI-generated illustrations for visual reference and may simplify natural variation. Fishery records are based on the cited agency sources. About fish illustrations
Fishery overview
The Henrys Fork near Island Park is the Island Park Dam / Box Canyon fishing reach. StrikeTracks publishes Monitoring-Backed conditions from USGS 13042500 (live discharge and stage). This MODEL-2A Monitoring-Backed identity is preserved; measured water temperature is not currently live. Distinct from Henrys Fork at Ashton. IDFG Upper Snake special rules for the Island Park Dam section are catch-and-release (except brook trout), no bait, barbless hooks. Harriman Ranch immediately downstream is a separate special-rule fly-fishing section and is not collapsed into this ID. Flow Context remains default-deny. Hatch Match publishes general fly suggestions only.
Target species
Brown Trout
Salmo trutta
- Expectation
- Primary
- Population
- Wild
- Native status
- introduced
- Confidence
- High confidence
IDFG Henrys Fork Island Park Dam special rules. USGS 13042500. Distinct from Ashton (13046000). Native cutthroat trout (Oncorhynchus clarkii, including Yellowstone and westslope forms where IDFG manages them) are not a StrikeTracks species-selector ID. They are described in overview and regulation caution only. Mountain whitefish (Prosopium williamsoni) are an IDFG game fish in many Idaho drainages and are not a StrikeTracks species-selector ID. Confirm current whitefish rules separately.
Rainbow Trout
Oncorhynchus mykiss
- Expectation
- Primary
- Population
- Unknown
- Native status
- introduced
- Confidence
- High confidence
IDFG Henrys Fork Island Park Dam special rules. USGS 13042500. Distinct from Ashton (13046000). Native cutthroat trout (Oncorhynchus clarkii, including Yellowstone and westslope forms where IDFG manages them) are not a StrikeTracks species-selector ID. They are described in overview and regulation caution only. Mountain whitefish (Prosopium williamsoni) are an IDFG game fish in many Idaho drainages and are not a StrikeTracks species-selector ID. Confirm current whitefish rules separately.
Brook Trout
Salvelinus fontinalis
- Expectation
- Present
- Population
- Wild
- Native status
- introduced
- Confidence
- High confidence
IDFG Fishing Planner lists brook trout among Henrys Fork game fish. Island Park Dam catch-and-release excepts brook trout.
Fishery characteristics
- Composition
- Wild
- Great Lakes tributary
- No
- Flow regime
- Tailwater
Henrys Fork below Island Park Dam, including the Box Canyon corridor. Harriman / Railroad Ranch is an adjacent special-rule section, not a second catalog identity.
Best seasons
- Spring
- Summer
- Fall
Common techniques
- Dry flies
- Fly fishing
- Nymphing
- Spinning
- Streamers
Access and Public Fishing Rights
Public fishing is documented by IDFG Fishing Planner, Harriman State Park, and Island Park access. Catalog coordinates are the USGS point. Harriman seasonal closure (December 1 through June 14) applies to the Ranch section, not automatically to every Island Park water.
Stocking information
IDFG Upper Snake Region manages this reach as a wild trout fishery. Confirm any current official stocking separately.
Official sources
IDFG Upper Snake 2025-2027: from the upper Harriman boundary to Island Park Dam — trout catch-and-release except brook trout; no bait; barbless hooks. Harriman Ranch itself is closed December 1 through June 14 and fly-fishing only June 15 through November 30. Do not copy Ranch rules onto Box Canyon or Ashton. Distinct from 13046000.
Hatch Match
General fly suggestions
- Parachute-style dryGeneral attractor dry family — not a claim that a named mayfly is hatching.
- Pheasant-tail-style nymphGeneral nymph family for trout rivers without destination hatch timing.
- Elk-hair-style dryGeneral dry/attractor family. Pattern choice only — not a report that caddis are hatching.
- Woolly-bugger-style streamerGeneral streamer family. Not a forage or insect Hatch event.
These are general fishing suggestions, not a report of insects currently hatching at this destination.
Location and Access
USGS monitoring location
Fremont, Idaho
The map marker represents the cataloged waterbody or monitoring location and may not indicate legal parking or public access. Confirm access through the official information before visiting.
River Details
County
Fremont
Management Category
Wild trout river
Regulation Scope
Henrys Fork near Island Park / Island Park Dam section
Regulation Summary
Henrys Fork near Island Park: IDFG Upper Snake Island Park Dam / Harriman map sections. Confirm current 2025-2027 Fishing Seasons & Rules.
Target Species
brown-trout, rainbow-trout, brook-trout
Access, Parking, and Regulations
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