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Big Thompson River

Starting as a mere trickle on the east side of the Continental Divide, inside Rocky Mountain National Park, the Big Thompson flows from Forest Canyon Pass near the top of Trail Ridge Road through Forest Canyon. As small drainages offer additional snowmelt, the Big Thompson picks up volume, turning into one of Colorado’s finest streams.

The Big Thompson becomes fishable at Moraine Park in Rocky Mountain National Park, about six miles downstream of its headwaters. It’s there at Moraine Park, where the river splits into numerous braids and channels, that fisherman encounter the river’s first public access. Trails leading up and down the river from that point will lead you to great flyfishing experiences.

Moraine is a wide-open area, but the Big Thompson’s banks are lined with willows. It’s typical small stream conditions, and the river is filled with, you guessed it, brook, brown, and cutthroat trout in the 6- to 12-inch range. They’ll readily take a variety of general attractor flies.

River description excerpted from Flyfisher's Guide to Colorado by Marty Bartholomew
River description excerpted from Flyfisher’s Guide to Colorado by Marty Bartholomew

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Latest Guide Report

Fishing Report Date: 02-20-2017

The Big Thompson below the dam is starting to fish well.  The flow on the river is still low, but midges are very active and it won’t be long until the Blue Winged Olives start hatching.  The ice in the canyon is dissipating and it wont be long before the entire canyon is open enough for fishing.

Fishing dry dropper is the best way to entice a strike.  Small midges sizes 18-22, pheasant tails sizes 16-20, top secret midges 20-24, KF emergers 20-24, johnny flash midges 20-24.  For dries, throw something on top that will support the nymph below.  Fish the deeper pockets and longer runs with a little bit of depth for the best success.  Best fishing times are still 10 until 2 or 3pm.

Report Statistics
3/5Time on Water:
Number of Anglers:
Hoook Ups:
Fish Landed:
Weather Experienced

Wind Conditions: Calm
Precipitation: None
Water Observations

Water Temperature:
Flow Level: CFS
Runoff? Clear

Report Submitted By: Randy Hanner

Big Thompson River Water Flow Graphs