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River guide · Colorado

Fly Fishing the Big Thompson River

Below Olympus Dam at Estes Park, the Big Thompson cuts a tight canyon down to the plains, its cold, regulated flows sustaining a blue-ribbon tailwater fishery for wild brown and rainbow trout that commonly push 20 inches. Summer evenings draw crowds to the caddis hatch, but spring midge fishing and fall Baetis seasons belong to the patient angler willing to fish small flies with a light touch.

  • 8 shops nearby
  • tailwater
  • Year-round (prime: March–October
  • Colorado
  • 6 key hatches
See fly shops ↓

The best time to fly fish the Big Thompson River is Year-round (prime: March–October. Key hatches include Midge, Blue, Caddis, Pale Morning Dun. 8 fly shops near the Big Thompson River can outfit your trip.

Fly shops near the Big Thompson River

Shops and guides that fish the Big Thompson River. See all 122 Colorado shops →

Fly Fish Estes ParkKirks FlyshopEstes AnglerFirst Cast Fly FishingAngles Sports Ski Board and Fly ShopSt. Peter's Fly Shop - SouthSt. Peter's Fly ShopLiarflies-Colorado Fly Fishing Adventures
8 fly shops shown

Species on this water

SalmonSteelheadTrout

Nearby towns

Estes ParkFort CollinsLongmont

Rivers nearby

Williams Fork RiverBlue RiverGore CreekSouth Platte River
Hatches & seasons

When & what to fish on the Big Thompson River

River typetailwater
Best seasonYear-round (prime: March–October; winter nymphing remains productive)
AccessU.S. Highway 34 runs alongside the river through Big Thompson Canyon, providing easy pull-offs and direct wade access along the approximately 9-mile catch-and-release section from Olympus Dam down to the Waltonia Bridge. No permit required; artificial flies and lures only in the C&R section.
Key hatches
  • Midge (year-round)
  • Blue-winged Olive / Baetis (March–May, Sept–Oct)
  • Caddis (June–August, prime evenings)
  • Pale Morning Dun (summer)
  • Stonefly (June–July)
  • Terrestrials (July–September)
From The Fly Bench

Tie the flies that work on the Big Thompson River

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

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Gear up

Gear up on the Big Thompson River

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

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The flies that work on the Big Thompson River

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Updated June 2026