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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: 05-19-2016

The Big T is hot and should be on your radar for this weekend. 

FRA Guide Craig King was out yesterday on the Big T and it continues to produce.

“The Big Thompson is hovering at 125 CFS which is a perfect flow for fishing in the Canyon.  Wading access is good and the water isn’t too fast.  Nymphing is the name of the game in the mornings.  Try double nymph rigs suspended under an indicator.  Best flies right now are Bishop’s Dynamite, Soft Hackle Sow Bugs, Poison Tungs, Rainbow Warriors, and Copper Ribbed RS2’s.  If it looks fishy, it probably is.  We found fish in tailouts, deeper pools and pockets, and in the faster water.  The fish are pretty spread out at this flow so work all of the water until you find a trend.  Each afternoon we’ve are starting to see some awesome BWO hatches.  Try parachute BWO patterns, sparke duns, film critics, and mole flies.  They should all pick up fish if you bump into a nice hatch. We should start seeing Caddis here any day as well.”  ~Craig K.

Want FRA to build you a Big Thompson Fly Selection?  Just give us a call and we will load you up with all the hot flies for your weekend fishing!

Big T


Report Statistics
4/5Time on Water:
Number of Anglers:
Hoook Ups:
Fish Landed:
Weather Experienced

Temperature: 55-65
Wind Conditions: Light-Breeze
Precipitation: None
Water Observations

Water Temperature:
Flow Level: 125 CFS
Runoff? Light-Stain
Zach Lass

Report Submitted By: Zach Lass

Big Thompson River Water Flow Graphs