Share your catch

Boulder River Fishing Report

Updated Fri, Sep 4, 2026 from live gauge and weather data

The Absaroka jewel: a boulder-strewn freestone falling out of the wilderness to the Yellowstone, thick with wild browns and rainbows.

2/5
Slow. Work for them.Conditions favor short windows and patient fishing.
Flow
90 cfs
Air / High
82 / 83 F
Wind
WSW 22 mph

Sources: USGS gauge 06200000, Open-Meteo, solunar calculated for these coordinates.

Satellite view
Friday
4
September 2026

Today's Fishing Report

Generated this morning from live readings: gauge, weather model, sun and moon. A fresh report is published here every morning.

2/5Slow. Work for them.Conditions favor short windows and patient fishing.

Boulder River feels the season turning: shorter days, grouping fish. The river is running 90 cfs, steady over the week. Today brings clear skies, wind WSW around 22 mph, rising pressure near 1003 hPa and a high of 83. Water sits around 54 F for the season (estimated). With the last quarter, the solunar majors run 5:39 AM-7:39 AM and 5:39 PM-7:39 PM: the windows to build the day around.

The plan, species by species

Rainbow troutGood

Blue-winged olives and midges on soft seams; streamers on overcast days move the better fish.

Brown troutGood

Pre-spawn aggression: this is streamer season for the fish of the year.

Tomorrow: Similar at 81 F. The solunar majors shift about 50 minutes later.Next report: Sat, Sep 5, 6:30 AMHow this report is made →

Water and weather

Live readings from Boulder River at Big Timber.

Flow, last 30 days

USGS gauge 06200000.

9410912490 cfs08/0508/1508/2509/04

Right now

Latest readings

Air temp82 F
High / Low83 / 54 F
WindWSW 22-36 mph
Pressure1002.7 hPa, rising
Sky / Rain0% cloud, 1%
Sunrise / Sunset06:45 / 19:52
MoonLast Quarter, 50%
Water temp (seasonal)~54 F est.

Bite planner

Hour-by-hour bite forecast for today. Tap a bar to see why.

5 AM8 AM11 AM2 PM5 PM8 PMsunrisesunset

Next 7 days

Tap a day for the detailed outlook.

Fri Sep 4 · Overcast, 83/54 F, wind 22 mph, rain 1%

Fair or better. A 22 mph breeze puts a working chop on the banks it hits: fish the wind-blown side.

Species guide

The species that matter on Boulder River: seasons, structure and how to fish each one. Today's ratings live in the report above.

Rainbow trout illustration

Rainbow trout

Best: Apr-Jun, Sep-Oct

The workhorse of western rivers: riffles, seams and dry-fly eats. Blue-winged olives and midges on soft seams; streamers on overcast days move the better fish.

Brown trout illustration

Brown trout

Best: Sep-Nov

Wary, predatory and nocturnal by preference. The big ones eat streamers. Pre-spawn aggression: this is streamer season for the fish of the year.

When to come: the Boulder River calendar

Activity by species and month, and how the water warms through the year. Tap any cell.

Species activity by month

1 = slow, 5 = peak. Current month highlighted.

J
F
M
A
M
J
J
A
S
O
N
D
Rainbow trout
Brown trout
SlowPeak

Water temperature through the year

Typical surface temperature for this water type; today is around 54 F (estimated, not a reading).

30405060JanMarMayJulSepNovSep, ~54 F now

Angler reports

Real reports from real anglers, reviewed before publishing. The water log below tracks each day automatically.

No angler reports yet this weekBe the first: your report helps every angler who checks Boulder River today, and we feature the best catch of the week.

Water log, last days

Auto-logged from live data
Thu, Sep 3

3/5 Fair. Fish the windows. A steady pattern: dawn and dusk carry the day. Rainbow trout led the card at good. High of 76 F, wind to 20 mph.

Wed, Sep 2

2/5 Slow. The wind owns today. 30 mph gusts make boat control the real battle. Rainbow trout led the card at good. High of 83 F, wind to 30 mph.

Tue, Sep 1

3/5 Fair. Fish the windows. A steady pattern: dawn and dusk carry the day. Rainbow trout led the card at good. High of 76 F, wind to 14 mph.

Where roughly, what depth, what bait. Skip anything you want to keep secret.
Only used to send you this water's report each week. No spam, ever.

Before you go

License

Montana requires a valid fishing license for adults. Buy online from the state agency; one-day options exist for visitors.

Regulations

Montana license + AIS pass. Standard western district trout rules: check FWP for the Yellowstone drainage.

Access

Accesses along Hwy 298: Boulder Forks, Big Rock, Natural Bridge SP; wilderness trailheads above.

About this water

Absaroka freestone joining the Yellowstone at Big Timber. The quiet sibling of the famous valley.

Fishing Boulder River: the full guide

Fifty miles of gradient

The Boulder drops out of the Absaroka-Beartooth Wilderness in a staircase of pocket water: plunge pools, boulder gardens and slicks holding wild browns and rainbows that see a fraction of the Yellowstone's traffic. The lower river (Natural Bridge down to Big Timber) floats in high water; most of the year it is a wade fishery of the classic Montana kind.

Pocket-water school

This is high-stick country: attractor dries with droppers, short drifts behind every rock, and fish that decide fast. The river teaches efficiency: hit the soft spots, move, repeat. Salmonflies and goldens climb the canyon in late June; hoppers own the August banks; October streamers move the big browns that run up from the Yellowstone.

Access rhythm

Highway 298 shadows the river south from Big Timber: fishing accesses and bridge crossings chain the lower thirty miles, and the McLeod stretch is the social center (the Road Kill Bar counts as angling infrastructure). Above Natural Bridge Falls the water turns wilderness: foot access, cutthroat, and solitude measured in trail miles.

A Boulder year

Runoff clears by late June most years: the window runs tight and sweet through October. July: stones and attractors. August: hopper banks and cold mornings. September-October: streamer browns and empty water. Winter belongs to the canyon and the whitefish: locals nymph the slicks on warm afternoons.

Common questions

How does the Boulder compare to the Yellowstone?

Smaller, steeper, more intimate: pocket water instead of big drifts, wading instead of boats, and browns that average honest with real surprises. Fish both: they are twenty minutes apart.

When can you float the Boulder?

Only in the higher flows of early summer, lower river only: most of the season it is a wading river. The pocket water is the point: bring studded boots and a staff.

Is fishing good at Boulder River right now?

Check the daily report at the top of this page: it is regenerated every morning from live data. Today's read: Slow. Work for them. Conditions favor short windows and patient fishing.

Nearby waters

Yellowstone River29 miGallatin River75 miJefferson River77 miEnnis Lake86 miCanyon Ferry Lake89 miMadison River90 mi
Share your catch