FISHABLE
Mid-winter mode with lowest flows of the year (~850-1,150 CFS). Shelf ice receding with recent warm spell. Nymphing productive in deep, slow runs.Yellowstone River
Current Hatch Activity
Sporadic midge hatches on warmer afternoons but surface feeding unlikely. Focus subsurface: Zebra Midges #18-22, Harrop's Hanging Midge #18-22, Brook's Sprout Midge Gray #20. Check slow back-eddies and foam lines for any surface activity.
FISHABLE
Tandem nymph rig: Black Jigged Perdigon #16 + Tungsten Zebra Midge #18-20. Streamers: Sparkle Minnow #4-6 dead-drifted slow.
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.
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Weekly flow updates and fishing intel.
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