Dry FliesCDC&Elk
The CDC&Elk is a versatile dry fly pattern designed by Hans Weilenmann in 1992 that combines the proven wing silhouette of Al Troth's Elk Hair Caddis with the natural movement of CDC fibers. This deceptively simple pattern works as a caddis imitation, mayfly match, emerger, or general searching pattern across diverse waters.
Spring, Summer, Fall
Beginner
Trout
Feb 2026
Overview
Hans Weilenmann created the CDC&Elk based on his "trigger" philosophy—offering fish multiple positive triggers to elicit a strike response. The straggling CDC barbs suggest legs, antennae, trailing shucks, or crippled wings, while the deer hair wing provides excellent buoyancy. Since its creation, the pattern has proven effective across multiple continents on a wide variety of trout waters.
Materials
Hook: Tiemco 102Y, #11-#17 (or equivalent dry fly hook)
Thread: Brown 6/0
Body/Hackle: CDC feather (Type 1)
Wing/Head: Fine-tipped deer hair
Behavior & Presentation
Natural Behavior: Adult caddis rest on the surface with tent-shaped wings, occasionally skittering to initiate flight or during egg-laying runs. Mayfly duns float with upright wings while their exoskeletons harden before takeoff.
Where Trout Eat It: Fish cruise the upper 6 inches of calm water, targeting adults drifting in seams, foam lines, and feeding lanes.
How to Fish It: Cast upstream with drag-free drifts through productive lies, or add subtle twitches to simulate caddis movement.
Best Water: Prime zones include tail-outs, slicks, seams, and riffle edges where surface insects concentrate and drift predictably.
Strike Type: Expect confident rises with visible head-and-shoulder movements, or delicate sips in calm slicks.
Fishing Strategy
Rigging Suggestions: Use a 9-12 foot leader tapering to 5X tippet for delicate presentations. Apply floatant to the body and hackle.
Seasonal Timing: Most effective during peak feeding periods at dawn and dusk. Water temperatures between 45-65°F typically produce best results.
Pro Tips: Floats exceptionally well due to the CDC body and deer hair wing. The elk hair wing provides good visibility in various light conditions.
Entomology
When freshly emerged caddisflies dry their wings while drifting, they ride the current in a low profile with wings partially unfurled, occasionally twitching to test flight readiness. Trout intercept these vulnerable adults before they escape, targeting the brief window when insects are trapped between aquatic and terrestrial life.
- Order
- Trichoptera
- Common Name
- Caddisfly
- Organism Type
- insect
- Life Stage
- adult