Fly fishing report · West

Henry's Fork

A lower Henry's Fork planning page for the St. Anthony-to-Menan corridor, built around float access, lower-river rules, and realistic decisions about wind, weeds, and side channels.

Check flow & weather

Today's river scoreHigh source confidence

Poor

Best option: Float.

A float can fit better than wading only if launches, shuttle, boat skill, wind, and local rules all check out.

Updated Jul 13, 11:17 PM UTCUsually refreshes about every 45 minutes

Recommended approachFloat

Mode scores adjust the river-wide score for the risks of wading, bank fishing, or floating.

Wade9/100

Wading is the most sensitive plan today. Use protected edges only, avoid crossings, and downgrade quickly if clarity or current feels wrong.

Bank / edgeCheck

This report does not describe this as a primary mode. Verify legal access, depth, launches, and retreat options before planning around it.

Float · Best fit48/100

A float can fit better than wading only if launches, shuttle, boat skill, wind, and local rules all check out.

Confirm before you leave

Flow and weather right now.

Use the flow trend to confirm the score before you leave. Weather can change the safest and most productive fishing window.

River strategy

Treat the lower Henry's Fork like a float-and-access river, not a clone of the ranch water upstream.

The St. Anthony corridor is broader, slower, and more wind-sensitive than the famous upper river. Use the St. Anthony gauge first, then decide whether you want a short float, a bank-and-slough day, or a different river entirely if weeds, wind, or summer traffic stack against you.

Use RiverReports first for the public chart, then confirm the lower-river trend with USGS 13050500 at St. Anthony.
IDFG reach lines matter here because the lower corridor carries a simpler two-trout framework than the more restrictive technical water upstream.
BLM and IDFG access sites around Red Road, Warm Slough, and Menan make this a practical float corridor when launches and wind cooperate.
If the river is weedy, windy, or crowded with pleasure traffic, commit to fewer cleaner drifts or move before the day turns into endless repositioning.

Why this score moved

HeatLowers score

The NWS forecast is near 98F and this page does not have live water temperature. Treat trout and salmonid fishing as unsafe unless a stream thermometer proves otherwise.

Public alertUse caution

A heat alert is active near this forecast point, so the score is capped until water temperature and fish-handling risk are checked. NWS alert: Extreme Heat Warning issued July 13 at 2:50AM MDT until July 13 at 9:00PM MDT by NWS Pocatello ID.

Best mode nowUse caution

Float: A float can fit better than wading only if launches, shuttle, boat skill, wind, and local rules all check out.

FlowHelps score

USGS shows 1,090 cfs with a stable over about 6 hours trend. same-date USGS history (1919-2025, 107 readings) puts the normal middle range around 883 cfs-1,380 cfs. Flow is inside the same-date normal range, so weather, temperature, and access become the next checks.

SeasonHelps score

Summer: A practical float and hopper season, but wind, weeds, and recreational use become bigger factors.

Read the water

What changes the plan.

The lower Henry's Fork is most useful when flows are steady, afternoon wind stays reasonable, and you have a clear launch or walk-in plan. It loses value fast when anglers show up expecting upper-river dry-fly precision from a much broader lower-valley system.

Lower steady flow

Best for side-channel scouting, cleaner weed lanes, and manageable bank or boat angles.

Stable medium flow

A good all-around lower-river level if wind and boat traffic stay modest.

High or pushy flow

Focus on launch-to-takeout planning first because the river spreads out and loses easy wading options quickly.

Heavy weed and wind

Downshift expectations, fish sheltered lanes, and avoid pretending every drift needs to be forced.

Field plan

Fish it with intention.

Best flows

Stable lower-river flows that keep side channels defined without flooding soft banks or turning weed lanes into constant fouling.

When to skip

Skip when hard valley wind, thick weed mats, or crowded launches turn the lower river into a boat-control problem instead of a fishing problem.

Local plan

Use the St. Anthony gauge first, pick one access cluster like Red Road or Warm Slough, and commit to a shorter cleaner day instead of chasing miles of similar-looking lower water.

Backup water

If the lower Henry's Fork is too weedy or windy, move to the Ashton-focused Henry's Fork route for a different style or switch to the South Fork Snake if you still want a larger drift-day setup.

Hatches & flies

Bring a flexible box.

TimingWhat to watchUseful flies

SpringMidges, BWOs, and caddisZebra midge, BWO emerger, soft hackle, caddis pupa

Reviewed pattern · report says “Zebra midge”Zebra MidgeLook for a very slim tapered thread body, evenly spaced contrasting wire rib, a small bead, and no tail or wing. The reviewed classic is black with silver wire and a silver bead. Red, olive, brown, glass-bead, jig-hook, resin-coated, or tailed forms must remain labeled variations rather than replacing the classic identity.See photos & how to fish it

Reviewed family · report says “BWO emerger”Blue-Winged Olive PatternsBWO describes a hatch group, not one fly. Nymph, emerger, dry, cripple, and spinner profiles must stay separate because they occupy different parts of the water column.See family guide + 2 more reviewed guides in the Fly Box

Early summerCaddis, PMDs, and stonefly leftoversPMD dry, elk hair caddis, prince nymph, rubberlegs

Reviewed family · report says “PMD dry”Pale Morning Dun PatternsPMD names an insect group, not one fly. Pale nymphs, trailing-shuck emergers, upright or low-riding duns, cripples, and spent-wing spinners stay visibly separate.See family guide

Reviewed pattern · report says “elk hair caddis”Elk Hair CaddisLook for a tented elk- or deer-hair wing, clipped hair head, dubbed body, rib, and hackle palmered along the body. The body color should be labeled because tiers often match different natural caddis colors.See photos & how to fish it + 2 more reviewed guides in the Fly Box

SummerCaddis, terrestrials, and evening spinner windowsHopper-dropper, beetle, ant, rusty spinner

Reviewed family · report says “beetle”Beetle PatternsBeetle flies range from simple foam shells to hair-bodied and sunken forms. A rounded back and compact profile distinguish the family from ants and hoppers.See family guide

Reviewed family · report says “ant”Ant PatternsAnt patterns can be foam, fur-bodied, winged, or sunken. The narrow waist and paired body lobes matter more than one material recipe.See family guide + 1 more reviewed guide in the Fly Box

FallBWOs, midges, and small streamersParachute BWO, RS2, zebra midge, olive bugger

Reviewed family · report says “Parachute BWO”Blue-Winged Olive PatternsBWO describes a hatch group, not one fly. Nymph, emerger, dry, cripple, and spinner profiles must stay separate because they occupy different parts of the water column.See family guide

Reviewed pattern · report says “RS2”RS2Start with the beadless architecture: two dark-dun Microfibett tails separated behind a slim, tightly twisted and visibly segmented dubbed abdomen; a fuller thorax; and saddle-hackle web clipped into a short angled wing bud. Rim Chung's original-style form uses natural beaver dubbing and hackle web. CDC- or Antron-wing ties, beads, curved hooks, flash, and tailless Avatar-style flies must remain labeled variations.See photos & how to fish it + 2 more reviewed guides in the Fly Box

Pick one access corridor and fish it with purpose instead of trying to sample every launch between St. Anthony and Menan.

Use weed lanes, side channels, and slower bank structure more than the broad flat middle of the river.

Float only if your put-in, take-out, and shuttle are settled before you rig rods.

When wind rises, shorten drifts and fish protected water instead of fighting open straightaways all afternoon.

Access & responsibility

Know the entry. Know the exit.

IDFG's 2025-2027 Henry's Fork rules split the river into multiple sections. The lower reach from the South Fork Snake confluence upstream to Vernon Bridge carries a 2-trout limit with no cutthroat harvest, while upstream reaches shift into more restrictive seasonal and gear rules. Check the current rulebook before choosing your section.

Red Road Bridge boat access

The best lower-river BLM starting point for a St. Anthony-facing float plan.

Warm Slough access site

Important IDFG launch and day-use anchor when you want easy public staging close to the lower corridor.

Menan Butte and Beaver Dick takeout corridor

Useful downstream public access when you want a shorter or more deliberate float finish.

Transparent sources

Check the facts behind the plan.

Last material review: 2026-06-02

flowRiverReports: Henry's Fork at St. Anthony flowUSGS monitoring location: Henrys Fork at St. Anthony regulationIdaho Fishing Planner: Henrys Fork Snake River accessBLM Henrys Fork access at Red Road, Warm Slough, Beaver Dick, and Menan accessIdaho Fish and Game Warm Slough access site update safetyNational Weather Service forecast point near St. Anthony

Common questions

Before you leave.

What part of Henry's Fork does this page cover?+

This page is built for the lower St. Anthony-to-Menan corridor, not the technical ranch and Ashton water farther upstream.

Is this mostly a wade river or a float river?+

It can be both, but the lower river makes the most sense when you plan around public launches, side channels, and a realistic float or bank-access lane.

What gauge should I trust for this reach?+

Start with RiverReports and USGS 13050500 at St. Anthony because they match the lower-river corridor far better than the upstream Ashton gauge.