Nf Big Wood River near Sawtooth Nra Hq near Ketchum
Nf Big Wood River · Rockies · USGS gage 13135520
Coldwater (summer mean 10.8°C — prime coldwater).
Water
50°F
Flow
26 cfs
Air
50°F
Sky
25%
Pressure
30.01 in
Wind
2 mph
Predicted hatches · 2026-09-18
PredictedBlue-Winged OliveBaetis spp.0.50
Predicted by conditions; no reports yet. water 10.2°C (50°F) sits in the prime band (6-11°C); shoulder of the season; watch midday, especially overcast afternoons.
flies: BWO Sparkle Dun #18-22, RS2, Pheasant Tail #18
PredictedMidgeChironomidae0.48
Predicted by conditions; no reports yet. water 10.2°C (50°F) is cooling past the prime band (1-10°C); shoulder of the season; 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.