It’s a fishing day

Henry’s Fork (Island Park) fishing conditions · Idaho

Now until 6 pmRainbow trout

The bite peaks at 76.

Log a trip here
Right now: 76 for rainbow trout, worth the trip · inside the best windowTap or drag along the water to move through the next 36 hours

Rainbow trout, hour by hour

Each float is an hour. The deeper it rides, the better the bite. The strip underneath runs daylight, dusk and dark; the red rule marks the best window. Click any hour to read it.

  1. 762 pm
  2. 76
  3. 74
  4. 745 pm
  5. 64
  6. 64
  7. 648 pm
  8. 64
  9. 64
  10. 6411 pm
  11. 64Sun
  12. 64
  13. 642 am
  14. 64
  15. 64
  16. 645 am
  17. 64
  18. 64
  19. 648 am
  20. 66
  21. 74
  22. 7411 am
  23. 74
  24. 74
  25. 742 pm
  26. 74
  27. 74
  28. 645 pm
  29. 64
  30. 64
  31. 648 pm
  32. 64
  33. 64
  34. 6411 pm
  35. 64Mon
  36. 64
Go, 85+Worth the trip, 70+Marginal, 55+Sit it out

Right now · best window

Water
No reading

Rainbow trout range 45–68°

Wind
3 mph

From the south-southwest

Flow
82.6 cfs

steady · +0% in 24 h

Light
Daylight

Sunset 5:07 pm

Sky
Sunny

No rain expected

Air
47°F

NWS hourly forecast

Barometer
Falling

Measured, last 3 hours

Moon
5% lit

Waning crescent

What’s biting

Each species is scored against its own water-temperature range and tide preference, then wind, weather and warnings. The rules are Idaho non-tidal regulations for these waters.

Rainbow Trout

Rainbow trout

Oncorhynchus mykiss

76Worth the tripNow until 6 pm

Water

No water reading here right now. Rainbow trout bite in 45–68° water, best near 55°.

Why

Fish feed actively ahead of a pressure drop. Settled river level — clearer water, easier wading. Holds 3–20 ft down.

Keep

no harvest

Catch and release only today. Catch-and-release for all trout except brook trout; no bait, barbless hooks. Downstream, the Harriman Ranch is closed Dec 1–Jun 14 and fly-fishing-only catch-and-release Jun 15–Nov 30.

Verified Oct 23, 2026 · Henrys Fork, Island Park Dam to the upper Harriman State Park boundary (Box Canyon)

Last checked 15 days ago. Rules may have changed.

More on rainbow trout

Brown Trout

Brown trout

Salmo trutta

76Worth the tripNow until 6 pm

Water

No water reading here right now. Brown trout bite in 45–68° water, best near 55°.

Why

Fish feed actively ahead of a pressure drop. Settled river level — clearer water, easier wading. Holds 3–25 ft down.

Keep

no harvest

Catch and release only today. Catch-and-release for all trout except brook trout; no bait, barbless hooks. Downstream, the Harriman Ranch is closed Dec 1–Jun 14 and fly-fishing-only catch-and-release Jun 15–Nov 30.

Verified Oct 23, 2026 · Henrys Fork, Island Park Dam to the upper Harriman State Park boundary (Box Canyon)

Last checked 15 days ago. Rules may have changed.

More on brown trout

Brook Trout

Brook trout

Salvelinus fontinalis

76Worth the tripNow until 6 pm

Water

No water reading here right now. Brook trout bite in 40–65° water, best near 52°.

Why

Fish feed actively ahead of a pressure drop. Settled river level — clearer water, easier wading. Holds 1–10 ft down.

Keep

25 a day

Open. Keep fish within the limits. Idaho general rules: 25 brook trout a day, separate from the trout limit. Brook trout may be kept where other trout are catch-and-release unless a rule says otherwise.

Verified Oct 23, 2026 · Idaho non-tidal

Last checked 15 days ago. Rules may have changed.

More on brook trout

The water

  • Water temperatureNo reading
  • River82.6 cfs · steady · +0% in 24 h
  • Barometer30.35 inHg, falling

Sun, moon & solunar

  • Sunset today5:07 pm
  • Sunrise tomorrow7:12 am
  • MoonWaning crescent, 5% lit
  • Minor solunarToday 3:40 pm–4:40 pm
  • Major solunarTonight 10:20 pm–12:20 am
  • Minor solunarTomorrow 6:30 am–7:30 am

Solunar tables are a popular heuristic. A peer-reviewed test found they don’t predict catch on their own, so here they only nudge the score when the tide or moon already agree. How the score works

Fishing report

No current report covers these waters.

We only show reports an agency has published, with their date. Idaho Fish & Game has the state’s fishing pages.

Licenses and rules: Idaho Fish & Game · trout stocking · fish-consumption advisories

About this spot

A fly-fishing mecca on Idaho’s upper Snake plateau, famous for the slow, glassy spring-creek water through Last Chance and the Harriman “Ranch.” Big, selective wild rainbow and brown trout sip technical mayfly hatches — the green drake and PMD emergences are legendary. The Box Canyon above it offers faster pocket water.

Box Canyon, below Island Park Dam: catch-and-release for every trout but brook trout, no bait, barbless hooks. The Harriman Ranch downstream is closed Dec 1–Jun 14, then fly-fishing-only catch-and-release; from the Ranch down to Riverside Campground every trout but brook trout is released.

Nearby

Public spots within 40 miles, with the same 36 hours of floats.

Madison River34 mi · MontanaBest now until 6 pm
90Go

Questions people ask

Do I need a fishing license to fish at Henry’s Fork (Island Park)?

Yes (anglers age 16 and older). To fish at Henry’s Fork (Island Park) you need the appropriate state fishing license. See the agency's current rules: the state agency website

What fish are commonly targeted at Henry’s Fork (Island Park)?

Henry’s Fork (Island Park) is listed on this site for 3 commonly-targeted species: Rainbow Trout, Brown Trout, Brook Trout. Which species is currently in season and which is scoring highest today is shown in the per-species ranking on this page.

When is the best time to fish at Henry’s Fork (Island Park)?

It depends more on the species and the day's conditions than on a fixed "best hour." Water temperature, weather, and — at tidal locations — the stage of the tide drive activity most. The per-species ranking on this page scores every target species at Henry’s Fork (Island Park) against today's live conditions, so the fish near the top are your best bets right now; check back as conditions change through the day.

What kind of access does Henry’s Fork (Island Park) have?

Henry’s Fork (Island Park) has multiple access types — pier, shoreline, and at least one public boat ramp. Box Canyon, below Island Park Dam: catch-and-release for every trout but brook trout, no bait, barbless hooks. The Harriman Ranch downstream is closed Dec 1–Jun 14, then fly-fishing-only catch-and-release; from the Ranch down to Riverside Campground every trout but brook trout is released.

Which state's fishing regulations apply at Henry’s Fork (Island Park)?

state agency regulations apply at Henry’s Fork (Island Park). Size limits, creel limits, and seasonal closures are listed per species on each species page. Always confirm against the agency source linked from each regulation block — emergency closures can take effect mid-season.

Is Henry’s Fork (Island Park) tidal water?

No. Henry’s Fork (Island Park) is non-tidal — water level varies with rainfall, seasonal flow, and (where applicable) upstream dam releases rather than tidal exchange.