Big Sky to Gallatin Gateway, Montana

Gallatin River Fishing Report

Gallatin River | Big Sky to Gallatin Gateway, Montana | Updated Apr 24, 2026, 7:09 AM MDT | Station: Gallatin River above Deer Creek, near Big Sky

Stay subsurface most of the day and cover pocket water fast with a compact stonefly-and-mayfly rig.

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Today's Read

Gallatin trout in late April usually hold in short, defined pockets where they can feed without spending energy in the main push. Most fish will eat a good nymph drift before they will move far for a dry. Surface action is real on the right afternoons, but it tends to be concentrated in softer edges, protected tailouts, and any place current slows enough for BWOs and midges to collect.

Bugs & Best Matches

What's active
Fish this
Blue-winged olives, size 18-20, midday on overcast days
BWO Sparkle Dun, size 18-20, dry; RS2 olive, size 20-22, emerger
Midges, size 18-22, early and late in slower water
RS2 olive, size 20-22, emerger
Small black stoneflies, size 14-16, afternoons near banks and rough edges
Pat's Rubber Legs, size 8-10, nymph
General subsurface
Frenchie, size 16-18, nymph; Perdigon olive or black, size 16-18, nymph; Parachute Adams, size 16-18, dry

What Is Driving The Feed

  • Blue-winged olives, size 18-20, midday on overcast days
  • Midges, size 18-22, early and late in slower water
  • Small black stoneflies, size 14-16, afternoons near banks and rough edges

Current Conditions

FlowSpring flow is usually clear in the upper canyon but can rise fast with warm weather or dirty tributary input lower down.
Water TempCold water keeps fish grouped in softer current breaks and short feeding lanes.
WeatherClouds help the hatch. Bright sun usually pushes the better fish deeper or tighter to structure.
Rating6/10