Missouri River below Holter Dam near Wolf Creek
Missouri River · Rockies · USGS gage 06066500
Trout (marginal) (summer mean 17.9°C — trout, warm in summer).
Water
62°F
Flow
3,160 cfs
Air
57°F
Sky
100%
Pressure
30.04 in
Wind
17 mph
Predicted hatches · 2026-09-14
ConfirmedSpotted / Summer CaddisHydropsyche spp.0.63
Model says likely and 1 recent report confirm it. water 16.4°C (62°F) sits in the prime band (14-19°C); shoulder of the season; 8 days sustained ≥12°C; watch evening, last hour of light.
reports: Yellow Dog — Missouri River Reports
flies: Elk Hair Caddis #14-16, Iris Caddis, X-Caddis
ConfirmedHopper / TerrestrialsAcrididae (grasshoppers)0.62
Model says likely and 1 recent report confirm it. water 16.4°C (62°F) is warming toward the prime band (17-24°C); shoulder of the season; 8 days sustained ≥14°C; wind puts terrestrials in play; watch warm, breezy afternoons.
reports: Yellow Dog — Missouri River Reports
flies: Morrish Hopper #8-12, Chubby Chernobyl, Dave's Hopper
ConfirmedTricoTricorythodes spp.0.62
Model says likely and 1 recent report confirm it. water 16.4°C (62°F) sits in the prime band (16-21°C); shoulder of the season; 8 days sustained ≥15°C; watch early morning spinner falls.
reports: Yellow Dog — Missouri River Reports
flies: Trico Spinner #20-24, CDC Trico, Griffith's Gnat
PredictedSlate Drake / IsonychiaIsonychia spp.1.00
Predicted by conditions; no reports yet. water 16.4°C (62°F) sits in the prime band (16-21°C); peak season; 8 days sustained ≥14°C; watch afternoon/evening; nymphs crawl to shore to emerge.
flies: Isonychia #10-12, Slate Drake, Leadwing Coachman
PREDICTED from the first-principles model only. Report-confirmed signal (fly-shop & forum reports) is the next milestone.