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River guide · Montana

Fly Fishing the Boulder River

The Boulder flows wild and rocky from its headwaters in the Absaroka-Beartooth Wilderness down through a scenic canyon to the Yellowstone Valley near Big Timber, carrying wild rainbows, cutthroats, and browns through miles of lichen-crusted pocket water. It sees a fraction of the pressure of its famous neighbors, rewarding the angler who makes the effort with big fish and even bigger solitude.

  • 10 shops nearby
  • freestone
  • Mid-July–October (after runoff
  • Montana
  • 6 key hatches
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The best time to fly fish the Boulder River is Mid-July–October (after runoff. Key hatches include Blue, Golden Stonefly, Yellow Sally, Pale Morning Dun. 10 fly shops near the Boulder River can outfit your trip.

Fly shops near the Boulder River

Shops and guides that fish the Boulder River. See all 93 Montana shops →

Sweetcast AnglerGreater Yellowstone Flyfishing OutfittersYellowstone River OutfittersYellowstone Country Fly FishingWet Net Outfitters LLCAngler’s West Fly Fishing OutfittersMontana Angling CompanyMontana Fly Goods Co
8 fly shops shown

Species on this water

BassBonefishPanfishPikeTarponTrout

Nearby towns

Big TimberLivingstonEmigrant

Rivers nearby

Yellowstone RiverStillwater RiverRock CreekGallatin River
Hatches & seasons

When & what to fish on the Boulder River

River typefreestone
Best seasonMid-July–October (after runoff; floatable July–August)
AccessA forest service road follows the river from McLeod toward the Natural Bridge. Two public fishing access sites (Boulder Forks FAS and Big Rock FAS) provide entry below the canyon. Nearly all of the lower river flows through private ranchland; guided float trips are the primary way to access most of the best water.
Key hatches
  • Blue-winged Olive / Baetis (April, Sept–Oct)
  • Golden Stonefly (July)
  • Yellow Sally (July)
  • Pale Morning Dun (mid-July–August)
  • Caddis (summer)
  • Terrestrials / Hoppers (Aug–Sept)
From The Fly Bench

Tie the flies that work on the Boulder River

Step-by-step tying recipes & videos for these patterns.

Browse all 880+ patterns at The Fly Bench
Gear up

Gear up on the Boulder River

Everything you need before the next trip — rods, lines, leaders, and fly-tying materials.

Shop the gear Flies that work

The flies that work on the Boulder River

Find the most effective patterns for where you're fishing — and learn to tie them yourself, step by step.

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Updated June 2026