What flies are hatching on the Big Hole River right now?

Current and seasonal hatches on the Big Hole River include Salmonfly, Golden Stone, Caddis. Use the AI Hatch Advisor on this page for a live, temperature-aware recommendation.

What's the current flow on the Big Hole River?

The Big Hole River is running at 25 CFS at the Near Melrose gauge. Readings update every 15 minutes from the USGS Water Services API.

Is the Big Hole River fishable today?

Big Hole River is outside its fishable window right now. Flow is 25 CFS at the Near Melrose gauge. Check back when conditions return to the normal range.

Big Hole River Fly Fishing Conditions

Live Conditions

Big Hole River — Near Melrose

Unfishable

25CFS

Discharge

2.07ft

Gauge Height

70.9°F

Water Temp

Updated 1 hr agoView on USGS ↗

7-Day Flow

↓ Falling

RisingFallingStable

24-Hr Pressure

24.22 inHg · → High/stable

Falling (good)RisingHigh/stable

Voluntary Catch-and-Release Advisory

Water temperature is at or above 65°F. At these temperatures trout are physiologically stressed and have a higher post-release mortality rate. Consider waiting for cooler conditions — early morning or evening — or choosing a tailwater with regulated temperatures.

Local Weather

61°FClear sky

Wind 9 mph24.22 inHg Low & stable

Tough conditions — fish deep

Today

☀️

Clear sky

74° / 49°

Tomorrow

☀️

Clear sky

67° / 43°

Tue

☀️

Clear sky

73° / 39°

Wed

☀️

Clear sky

81° / 42°

Cold front incoming — go deep with nymphs, surface activity likely slow.

Weather by Open-Meteo · No API key · Updated every 30 min

What should I fish today?

⚡ AI

AI-powered recommendation using today's live flow, temperature, and hatch data.

2

Time of Day

Using: 25 CFS · 70.9°F · PMDs continue. Hoppers

What should I pack?

Rod, flies, tippet, and safety gear specific to today's Big Hole River conditions.

🪰 Hatch Calendar

Big Hole River · August · Late Summer

Full calendar →

🟡 Approaching — within 5°F of trigger range

Caddis

Select month

JanDec

PMDs continue. Hoppers (size 8-12) productive. EMERGENCY CLOSURES POSSIBLE — Big Hole regularly closes mid-summer when temps exceed 73°F to protect Arctic Grayling. Check FWP daily before driving out.

PMD

🟢 Active · 🟡 Approaching · ⚪ Seasonal only

River Map

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USGS Gauge (click for site ID)Fishing Access / SectionScroll to zoom disabled — use map controls

About Big Hole River

Last river in the lower 48 holding native fluvial Arctic Grayling alongside browns, rainbows, and brookies. Wild high-meadow freestone with classic Salmonfly and Golden Stone hatches in early summer.

SalmonflyGolden StoneCaddisPale Morning DunHopperBlue-Winged Olive

Regulations

Native Arctic Grayling — handle with extreme care and release immediately. Hoot-owl restrictions (afternoon closures) and full emergency closures are common when water temps exceed 73°F in summer; check FWP daily before fishing in July–August.

Learn More

Guides to help you fish Big Hole River with more confidence.