Gallatin River at Logan
Gallatin River · Montana · USGS gage 06052500
Lower Gallatin near Logan / Three Forks. Freestone trout water; warms in summer.
Water
76°F
Flow
455 cfs
Air
n/a
Sky
n/a
Pressure
n/a
Wind
n/a
Predicted hatches · 2026-07-31
PredictedHopper / TerrestrialsAcrididae (grasshoppers)0.48
Predicted by conditions; no reports yet. water 24.3°C (76°F) is cooling past the prime band (17-24°C); shoulder of the season; 8 days sustained ≥14°C; watch warm, breezy afternoons.
reports: Montana Angler — Gallatin Report
flies: Morrish Hopper #8-12, Chubby Chernobyl, Dave's Hopper
PredictedHexagenia (Hex)Hexagenia limbata0.31
water 24.3°C (76°F) is cooling past the prime band (19-23°C); shoulder of the season; 8 days sustained ≥18°C; bright moon — night activity; watch after dark — the famous night hatch.
flies: Hex Dun #4-8, Hex Nymph, Hex Spinner
PREDICTED from the first-principles model only. Report-confirmed signal (fly-shop & forum reports) is the next milestone.