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CDC EmergerEmergerintermediate

Rocky Mountain West

CDC Emerger

Flybox sourcing profile

No TWG price or checkout is active. Use this page to validate the fly, then source it through the mapped tier or trusted fly shops.

Available Sizes#14 - #22
Color Variations
OliveTanGrayRusty Brown

Pattern Ledger

Source CDC Emerger

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Sourcing Ledger

Where to source this pattern

TWG checkout is closed. These are current sourcing leads, scored by mapped tier, region, species, fly type, and named-pattern evidence. Confirm availability directly with the tier or shop.

Regional shopStrong match

Taos Fly Shop

Matched on Rocky Mountain West, emerger flies, trout. New Mexico/Southwest trout shop lead for Rio Grande, San Juan, Pecos, and high desert water.

Rocky Mountain Westemerger fliestrout
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Signature tierStrong match

Rocky Mountain Fly Design

Matched on Rocky Mountain West, emerger flies, trout. Colorado tier and shop lead for Rocky Mountain trout, bass, and predator patterns.

Rocky Mountain Westemerger fliestrout
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Signature tierStrong match

Stillwater Fly Fishing Store

Matched on Rocky Mountain West, emerger flies, trout. Specialist stillwater source for balanced leeches, chironomids, and lake-trout logic.

Rocky Mountain Westemerger fliestrout
Visit source
Broad sourceStrong match

Fly Fish Food

Matched on emerger flies, trout, mayfly. Strong technical tying and trout catalog coverage, especially nymphs, dries, and stillwater flies.

emerger fliestroutmayfly
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Broad sourceStrong match

Fulling Mill Flies

Matched on emerger flies, trout, dry. Large pattern house with broad freshwater and saltwater fly categories.

emerger fliestroutdry
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CDC -- cul de canard -- comes from the oil gland area of a duck, and it floats without chemical assistance because evolution is a better engineer than any fly tier. This emerger hangs in the surface film like a mayfly stuck between one life and the next, and trout eat it because vulnerability is apparently delicious. It is the most elegant solution to the selective trout problem, provided you do not apply floatant and ruin the natural oils. Which you will do once, and only once.

Quick Facts

TypeEmerger
Difficultyintermediate
SeasonsSpring, Summer, Fall
Target SpeciesRainbow Trout, Brown Trout, Cutthroat Trout
Sizes#14 - #22
Best LocationsHenry's Fork, ID; Missouri River, MT; Frying Pan River, CO

Where to Fish It

Henry's Fork

ID · Spring Creek

Missouri River

MT · Tailwater

Frying Pan River

CO · Tailwater

Map unavailable. Locations for CDC Emerger: Henry's Fork, ID; Missouri River, MT; Frying Pan River, CO

Related Reading

species science

How Trout See Your Fly: The Science of Color and Light

Trout don't see the world the way we do. They perceive ultraviolet light, detect motion through contrast rather than color, and see a dramatically different fly at ten feet of depth than at two. Once you understand their four-cone visual system, you'll never choose a fly the same way again.

hatch guide

The Complete Guide to Mayfly Hatches

Mayflies are the foundation of trout-stream entomology. This guide covers every major hatch — BWOs, PMDs, Green Drakes, Sulphurs, Tricos, and Hendricksons — with the biology, timing, and fly selections you need to fish them effectively across the country.

hatch guide

Caddis: The Underrated Hatch

Caddisflies outnumber mayflies on most trout streams, yet they receive a fraction of the attention. From the explosive Mother's Day caddis hatch to the giant October caddis of the Pacific Northwest, understanding Trichoptera transforms your fishing from spring through fall.

hatch guide

Midge Fishing: The Tiny Flies That Save the Day

When every other hatch has shut down, midges keep trout feeding. From winter tailwaters to high-altitude stillwaters, Chironomidae are the most abundant insects in freshwater ecosystems. Learning to fish these tiny patterns unlocks twelve months of dry-fly and nymphing opportunities.

hatch guide

Emerger Patterns: Fishing the In-Between

Trout eat more insects during emergence than at any other stage. Emerger patterns — flies that imitate the critical moment when a nymph transforms into an adult in the surface film — are the most consistently effective dry flies in fly fishing. Here is the science and the technique behind fishing the in-between.

technique

Fly Selection: A Decision Tree for Every Situation

Most anglers open their fly box and stare at it like a menu in a foreign language. But fly selection isn't mystical — it's a decision tree. Start with what the fish are eating, narrow by presentation depth, match the profile and size, and you'll arrive at the right fly in under sixty seconds. Here's the system.

technique

Nymph or Dry? The Decision That Changes Everything

Ninety percent of a trout's diet is consumed subsurface. Yet ninety percent of the magazine covers show a dry fly floating on calm water. The decision between nymphing and dry-fly fishing isn't about preference — it's about reading the situation and making the choice that puts your fly where the fish are actually feeding.

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