What flies are hatching on the Boulder River right now?

Current and seasonal hatches on the Boulder 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 Boulder River?

The Boulder River is running at 3,230 CFS at the Near Big Timber gauge. Readings update every 15 minutes from the USGS Water Services API.

Is the Boulder River fishable today?

Boulder River is outside its fishable window right now. Flow is 3,230 CFS at the Near Big Timber gauge. Check back when conditions return to the normal range.

Boulder River Fly Fishing Conditions

Live Conditions

Boulder River — Near Big Timber

Unfishable

3,230CFS

Discharge

2.97ft

Gauge Height

44.4°F

Water Temp

Updated 1 hr agoView on USGS ↗

7-Day Flow

→ Stable

RisingFallingStable

24-Hr Pressure

23.74 inHg · → High/stable

Falling (good)RisingHigh/stable

Local Weather

37°FFoggy

Wind 7 mph23.74 inHg Low & stable

Tough conditions — fish deep

Today

🌫️

Foggy

50° / 37°

Tomorrow

❄️

Snow

41° / 33°

0.21"

Mon

❄️

Snow

37° / 30°

0.25"

Tue

☁️

Overcast

50° / 30°

Snow in forecast — check road conditions before heading out.

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: 3,230 CFS · 44.4°F · Midges. BWOs on mild afternoons. Sections beginning to ice. Late-season fishing for the dedicated.

What should I pack?

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

🪰 Hatch Calendar

Boulder River · November · Late Fall

Full calendar →

🟡 Approaching — within 5°F of trigger range

Blue-Winged Olive

Select month

JanDec

Midges. BWOs on mild afternoons. Sections beginning to ice. Late-season fishing for the dedicated.

Blue-Winged OliveMidge

🟢 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 Boulder River

Small classic Montana freestone draining the Absaroka-Beartooth Wilderness south of Big Timber. Pocket water and meadow runs full of wild trout — a low-pressure alternative to the nearby Yellowstone and Stillwater.

SalmonflyGolden StoneCaddisPale Morning DunHopperBlue-Winged Olive

Regulations

Standard Montana trout regulations apply on the Boulder; cutthroat and brown trout are present in the upper reaches. Montana fishing license required. Verify current regs at fwp.mt.gov before fishing.

Learn More

Guides to help you fish Boulder River with more confidence.