Big Timber / Absaroka
Boulder River
Live Conditions
Boulder River — Near Big Timber
7-Day Flow
→ Stable
24-Hr Pressure
24.09 inHg · → High/stable
Local Weather
Tough conditions — fish deep
Today
☀️Clear sky
63° / 43°
Tomorrow
🌦️Drizzle
70° / 45°
0.02"
Fri
🌧️Rain
71° / 53°
0.32"
Sat
🌧️Rain
52° / 46°
2.22"
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?
⚡ AIAI-powered recommendation using today's live flow, temperature, and hatch data.
9.4
Time of Day
Using: 655 CFS · 61.3°F · Hopper season continuing. BWOs returning
What should I pack?
Rod, flies, tippet, and safety gear specific to today's Boulder River conditions.
🪰 Hatch Calendar
Boulder River · September · Early Fall
🟢 Active now at 61.3°F water
🟡 Approaching — within 5°F of trigger range
Select month
Hopper season continuing. BWOs returning (size 18-20). Cooling water, active fish. Fall colors through the Absaroka-Beartooth spectacular and uncrowded.
🟢 Active · 🟡 Approaching · ⚪ Seasonal only
River Map
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.
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.
Montana Fishing Regulations for Fly Anglers
Montana's Conservation License prerequisite and AIS pass, the third-Saturday-in-May to November 30 general stream season, blue-ribbon special regs on…
Trout Species of Montana
Montana's six salmonids and how to tell a harvestable brown from a release-required cutthroat or a protected bull trout. Missouri and Yellowstone…
Seasonal Guide to Montana Fly Fishing
Montana rivers are a completely different game each season — Salmonfly in late May, PMD and caddis in July, technical Trico on the Missouri in…