FISHABLE
Winter flows excellent, low and clearYellowstone River
Current Hatch Activity
Winter midge activity on sunny afternoons. Fish are concentrated in slower, deeper water. Patience pays off.
FISHABLE
Streamer (Woolly Bugger, Zonker) or nymph rig (Stonefly + Midge dropper)
Quick Reference
Under 8,000 CFS for good dry fly fishing. 8,000-10,000 CFS fishable with nymphs and streamers. Above 10,000 CFS is blown out.
45-62°F optimal. Summer temps can spike—fish early morning or evening in July/August.
The longest undammed river in the lower 48. Winter flows run 1,000-2,000 CFS. Spring runoff peaks mid-June, often exceeding 15,000 CFS. Typically fishable again by late June.
Watch the Corwin Springs gauge—sudden spikes mean mud is incoming from park tributaries. Fish downstream sections when upper river is off-color.
What "Fishable" Means Here
Fishable means you can effectively present flies to feeding trout. On the Yellowstone, that requires flows under 10,000 CFS with 12+ inches of visibility. At 6,000 CFS, both floating and wading become productive.
Seasonal Patterns
spring
Pre-runoff (March-May) offers good nymphing and streamer fishing. Mother's Day caddis can be excellent if timing aligns. Runoff typically blows things out mid-May through late June. Watch Corwin Springs gauge for clarity.
summer
Post-runoff (late June-July) kicks off prime season. Salmonflies and Golden Stones trigger explosive dry fly action. Hopper-dropper becomes king by August. This is the Yellowstone at its finest—big fish on big dries.
fall
September through October is exceptional. Browns get aggressive as spawning approaches. Streamers produce trophy fish. BWOs and October caddis provide consistent dry fly opportunities. Fewer anglers, excellent fishing.
winter
Low, clear flows (1,000-2,000 CFS) make for technical but productive fishing. Midges and small nymphs in slower water. Fish concentrate in deeper runs. Cold but worth it for solitude and willing fish.
Resources
River Intel Weekly
Weekly flow updates and fishing intel.
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