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
133 cfs
Air
63°F
Sky
100%
Pressure
29.64 in
Wind
2 mph
Predicted hatches · 2026-06-20
PredictedMidgeChironomidae0.53
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; low pressure — fish looking up; watch midday, especially cold months.
flies: Zebra Midge #18-22, Griffith's Gnat, Disco Midge
PredictedGreen DrakeDrunella spp.0.22
water 10.2°C (50°F) is warming toward the prime band (11-15°C); peak season; low pressure — fish looking up; watch midday, often cloudy.
flies: Green Drake Parachute #10-12, Cripple, Hares Ear #10
PREDICTED from the first-principles model only. Report-confirmed signal (fly-shop & forum reports) is the next milestone.