near Fork Flathead River near Columbia Falls
near Fork Flathead River · Rockies · USGS gage 12355500
Coldwater (summer mean 15.0°C — prime coldwater; very large river (6,450 cfs)).
Water
51°F
Flow
1,330 cfs
Air
47°F
Sky
100%
Pressure
30.11 in
Wind
4 mph
Predicted hatches · 2026-09-15
PredictedBlue-Winged OliveBaetis spp.0.57
Predicted by conditions; no reports yet. water 10.4°C (51°F) sits in the prime band (6-11°C); shoulder of the season; 7 days sustained ≥4°C; overcast skies favor it; watch midday, especially overcast afternoons.
flies: BWO Sparkle Dun #18-22, RS2, Pheasant Tail #18
PredictedMidgeChironomidae0.47
Predicted by conditions; no reports yet. water 10.4°C (51°F) is cooling past the prime band (1-10°C); shoulder of the season; 7 days sustained ≥0°C; watch midday, especially cold months.
flies: Zebra Midge #18-22, Griffith's Gnat, Disco Midge
PREDICTED from the first-principles model only. Report-confirmed signal (fly-shop & forum reports) is the next milestone.