It’s a fishing day

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

Tomorrow, 1 am–1 pmRainbow trout

The bite peaks at 74.

Log a trip here
Right now: 74 for rainbow trout, worth the tripTap 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. 741 am
  2. 74
  3. 74
  4. 744 am
  5. 64
  6. 64
  7. 647 am
  8. 64
  9. 64
  10. 6410 am
  11. 66
  12. 74
  13. 741 pm
  14. 74
  15. 74
  16. 744 pm
  17. 74
  18. 63
  19. 717 pm
  20. 71
  21. 64
  22. 6410 pm
  23. 64
  24. 64Tue
  25. 711 am
  26. 71
  27. 74
  28. 744 am
  29. 74
  30. 71
  31. 717 am
  32. 71
  33. 71
  34. 7110 am
  35. 71
  36. 71
Go, 85+Worth the trip, 70+Marginal, 55+Sit it out

Right now

Water
No reading

Rainbow trout range 45–68°

Wind
1 mph

From the northeast

Flow
87.9 cfs

steady · +0% in 24 h

Light
Dark

Sunrise 7:54 am

Sky
Areas Of Fog

1% chance of rain

Air
28°F

NWS hourly forecast

Barometer
Falling

Measured, last 3 hours

Moon
100% lit

Full

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

74Worth the tripTomorrow, 1 am–1 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

6 a day

Catch and release only today. Idaho general rules: 6 trout a day in rivers and streams, all species combined (2 in the Clearwater Region; only 2 of the 6 may be cutthroat in Magic Valley and Southeast region streams). Possession is 3 times the daily limit; open all year unless a special rule says otherwise.

Verified Oct 23, 2026 · Idaho non-tidal

More on rainbow trout

Brook Trout

Brook trout

Salvelinus fontinalis

74Worth the tripTomorrow, 1 am–1 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

More on brook trout

Brown Trout

Brown trout

Salmo trutta

66MarginalTomorrow, 1 am–1 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. Brown trout feeds less actively under bright moon. Holds 3–25 ft down.

Keep

6 a day

Catch and release only today. Idaho general rules: 6 trout a day in rivers and streams, all species combined (2 in the Clearwater Region; only 2 of the 6 may be cutthroat in Magic Valley and Southeast region streams). Possession is 3 times the daily limit; open all year unless a special rule says otherwise.

Verified Oct 23, 2026 · Idaho non-tidal

More on brown trout

The water

  • Water temperatureNo reading
  • River87.9 cfs · steady · +0% in 24 h
  • Barometer30.19 inHg, falling

Sun, moon & solunar

  • Sunrise today7:54 am
  • Sunset today6:24 pm
  • MoonFull, 100% lit
  • Major solunarToday 12:10 am–2:10 am
  • Minor solunarToday 8:10 am–9:10 am
  • Major solunarToday 12:30 pm–2:30 pm

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 12 pmDense Fog Advisory
55Marginal

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.