Montana ·
Bighorn River Fly Fishing Report - January 1/18/2026
BIGHORN RIVER FLY FISHING REPORT
Thermopolis & Below — Winter Window
Report Date: January 18, 2026 | Next Update: January 25, 2026
Current River Conditions
Winter nymphing is the story right now. Mild days have kept insect activity ticking and anglers are finding good numbers on subsurface rigs. Expect tight windows for dries — but serious production with bead jigs, Perdigons and sowbugs.
Flows & Clarity
Winter base releases from Yellowtail/Arbuckle are in effect. Water is clear to lightly stained in most runs — fish are concentrated in deeper seams, undercut banks and soft tails.
Winter base releases from Yellowtail/Arbuckle are in effect. Water is clear to lightly stained in most runs — fish are concentrated in deeper seams, undercut banks and soft tails.
Water Temperature
Surface: mid-30s°F (0–3°C) typical for January
Trend: occasional warm-sun afternoons will bump activity; cold fronts push fish deep
Surface: mid-30s°F (0–3°C) typical for January
Trend: occasional warm-sun afternoons will bump activity; cold fronts push fish deep
Weather & Wind
Pattern: mild spells broken by brief cold snaps this week. Light-to-moderate wind on exposed stretches; choose sheltered wading spots.
Pattern: mild spells broken by brief cold snaps this week. Light-to-moderate wind on exposed stretches; choose sheltered wading spots.
Access & Safety
Roads and ramps are generally open. Watch for ice near the banks and on rock shelves; single‑waders and drift boats are putting in with care.
Roads and ramps are generally open. Watch for ice near the banks and on rock shelves; single‑waders and drift boats are putting in with care.
What’s Hatchin’ & Where
| Insect | Size / Type | Where to Watch |
|---|---|---|
| Midges & Midges Emergers | #18–24 (midge clusters, micro-CH) | Slow tails, inside seams; best over cloudy, low-light periods |
| BWO / PMD Activity | #18–22 (emergers & thin dries) | Warm afternoons and sun breaks — look for selective rises |
| Sowbugs & Scuds | nymphs size 10–14 / scud patterns | Deeper soft-bottom runs and seams — year-round staple |
| Stoneflies (occasional) | #10–14 (nymphs and streamer-sized rubberlegs) | Pocket water and tailouts where stonefly nymphs hold |
Tactics — How to Fish It
Primary Method: Indicator / Euro nymph rigs. Fish long, slow drifts through the inside seams — tungsten jig nymphs and Perdigon-style thin profiles are producing.
Midge Strategy: Drop a zebra midge or small BH Perdigon on the dropper under an indicator or tight-line with a short leader. Keep presentations dead‑drift and subtle.
When the Sun Pops: Try small PMD/BWO emergers and parachute dries in the warmest hour. Even brief surface activity can steal a day of action.
Streamers: Slow strips in deep slots and along boulder tails will trigger winter browns — work the edges of current seams with baitfish/sculpin imitations.
Midge Strategy: Drop a zebra midge or small BH Perdigon on the dropper under an indicator or tight-line with a short leader. Keep presentations dead‑drift and subtle.
When the Sun Pops: Try small PMD/BWO emergers and parachute dries in the warmest hour. Even brief surface activity can steal a day of action.
Streamers: Slow strips in deep slots and along boulder tails will trigger winter browns — work the edges of current seams with baitfish/sculpin imitations.
Recommended Setups
Rods & Lines
9' 5–6wt for dries/dusting emergers; 6–7wt for big streamers & heavier nymph rigs.
Floating WF for dries; full‑sinking or sink-tip when fishing deep streamers.
9' 5–6wt for dries/dusting emergers; 6–7wt for big streamers & heavier nymph rigs.
Floating WF for dries; full‑sinking or sink-tip when fishing deep streamers.
Leader & Tippet
9–12ft fluorocarbon leaders for dries; 9–14ft tapered leaders for nymphs. 4–6X for PMD/BWO, 2–4X for indicators and streamers.
9–12ft fluorocarbon leaders for dries; 9–14ft tapered leaders for nymphs. 4–6X for PMD/BWO, 2–4X for indicators and streamers.
Rigging
Single tungsten jig or Perdigon on point with a scud/sowbug trailer; dropper midge under an indicator for tricky takes.
Single tungsten jig or Perdigon on point with a scud/sowbug trailer; dropper midge under an indicator for tricky takes.
Boat & Wading Notes
Boat anglers: favor slow drift through seam lines. Waders: pick sheltered runs and use felt/Studded boots where needed.
Boat anglers: favor slow drift through seam lines. Waders: pick sheltered runs and use felt/Studded boots where needed.
Top Fly Recommendations — Pick a Few and Fish Them Like a Pro
Nymphs & Jig Nymphs
These subsurface patterns are the most reliable on the Bighorn right now. Fish them tight to the bottom with tungsten and focus on depth in the cold water.
- Egan's Thread Frenchie Jig – Olive — compact jig profile that runs nose-down; perfect as a point fly on an indicator rig.
- Egan's Frenchie — versatile tungsten Frenchie for deeper tails and mid-channel pockets.
- Roza's World Spain Perdigon (barbless) — a tight, high‑sink Perdigon for fast, precise presentations.
- Tailwater Sowbug – Rainbow — the year‑round anchor fly; pair it under an indicator or as a trailer.
- Pheasant Tail Tungsten — classic mayfly nymph with tungsten mass for getting down to feeding fish.
Dry Flies & Emergers
Surface activity in winter is short but meaningful. Keep a small selection of emergers and caddis patterns ready for sun‑warmed spells.
- Corn-fed Caddis (CDC) — Tan — low‑profile CDC caddis that rides the surface and looks natural during brief hatches.
- Corn-fed Caddis (CDC) — Peacock — a slightly darker option for low light.
- Parachute — Blue Wing Olive — ideal for picky BWO rises; easy to see and gentle on the surface.
- Stealth Link Mercer — PMD — top choice for short PMD windows; fish as emerger or parachute.
Streamers & Sculpin Imitations
When fish congregate in deeper runs, slow‑stripbed streamers trigger aggressive takes. Run them along structure and let them sink into the cut.
- Coffey's CH Sparkle Minnow — Sculpin — heavy profile that reads like a sculpin in current; great as a big fish attractor.
- Sculpzilla — Olive — articulated sculpin imitation for slow, short strips.
- Near Nuff Sculpin — Olive — lifelike baitfish/ sculpin pattern for deeper holes.
- Galloup's Slick Willy — Whitefish — flat profile for long sweeps along current seams.
Midges & Micro Patterns
Small, high‑sink or jigged midge patterns are essential on the Bighorn in January. Keep ultra-fine tippet for these.
- Black Zebra Midge (TBH) — a winter staple; fish under an indicator or on the dropper.
- Tungsten Zebra Midge Thin — Black — fast sink for deep, tight presentations.
- Top Secret Midge — a reliable micro attractor for clear winter water.
- Jujubee Midge — Zebra — soft profile, great as a dropper or indicator fly.
Terrestrials & Short Windows for Dries
Even in January, wind‑blown ants and beetles can steal fish away from subsurface rigs — keep a couple terrestrials for opportunistic sipping fish near bank cover.
Quick Field Checklist (What to Pack)
- Indicator gear + Euro nymph setup (short, heavy point fly options)
- Selection of tungsten jigs, Perdigons, sowbugs and scuds
- A few small emerger/parachute dries (BWO/PMD) and CDC caddis
- Streamers: sculpin and baitfish profiles in olive/pearl
- Micro midges (zebra midge, TBH and TB tungsten options)
- Warm layers, ice cleats, and a good thermos — winter windows can be long and cold
Final Notes from the Guide
The Bighorn in January rewards the prepared angler. If you like methodical, technical nymphing, this stretch will hook you up. Switch tactics quickly when you see surface activity — a single well-presented emerger can change your day. Respect fish in shallow winter lies; play them quickly and revive properly for safe release.
