Fly Fishing the Firehole River

Arguably the most unusual trout river in the world, the Firehole flows through active geyser basins with steam rising alongside every cast, yet holds healthy brown and rainbow trout that demand precise, technical dry-fly presentations. Its geothermal warming makes it one of the first Yellowstone rivers to fish in spring and compresses the season into two distinct windows.

5 shops nearby

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When to fish

May 1 through mid-June

Best months: May–June, September–October

Best
Off-peak

Salmonfly — early June in Firehole Canyon: earliest in the region due to thermal warming.

Today's conditions

Where to fish

Biscuit Basin downstream to Firehole Falls

Moose1 shop

West Yellowstone1 shopJackson2 shops

Grand Loop Road parallels much of the fishable 10-mile stretch from Biscuit Basin downstream to Firehole Falls, with numerous signed pullouts and parking areas. Firehole Canyon Drive (one-way) accesses the canyon section below the falls. No fishing license is required inside Yellowstone National Park, though a park entry fee applies.

The water

Spring creek

Key hatches

Blue-Winged Olive
Caddisfly
Midge
Flav
Golden Stonefly

Hatch calendar

Conditions

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6-day forecast

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Forecast from the National Weather Service ↗

Hatch calendar

Months each hatch is active on the Firehole River, with hook sizes and local timing notes.
Hatch · hook	M	J	J	A	S	O
Blue-winged Olive(mayflies)hook #16–24	May	June	July	August	September	October
Caddisfly(caddis)hook #2–10	May	June	July	August	September	October
Midge(midges)hook #18–22	May	June	July	August	September	October
Flav(mayflies)hook #14–16		June
Golden Stonefly(stoneflies)hook #6–10		June	July
Mahogany Dun(mayflies)hook #14–18		June	July
Pale Morning Dun(mayflies)hook #16–20		June	July
Salmonfly(stoneflies)hook #2–8earliest in the region due to thermal warming		June	July
Yellow Sally(stoneflies)hook #14–16		June	July