How to Tie the Light Cahill Dry Fly Pattern
Learn how to tie the Light Cahill dry fly pattern, including step-by-step instructions, a video tutorial, pictures, and much more. Improve your fly-tying skills here.
Did you find this video helpful? We've got hundreds more just like it. Subscribe to Trident's YouTube Channel and enhance your fly-tying skills. New videos posted weekly in a variety of different patterns.
Material List
We've put together a kit that contains all the materials you need to tie this exact fly pattern.
Click the button below to shop the selection.
- Hook: TMC 100; Size 14
- Thread: Veevus 8/0; White
- Wing: Mallard Flank Feather
- Tail: Rooster Neck
- Body: Superfine Dubbing; Light Cahill
The Light Cahill is a highly respected dry fly pattern that originated in the Adirondack region of New York before quickly spreading throughout the northeastern United States. The Light Cahil imitates the Pale Morning or Pale Evening Dun mayflies, which are common during the summer months in many streams and rivers throughout the country.
The Light Cahill remains a highly effective dry fly thanks to its realistic silhouette that mimics the shape and movement of a mayfly on the water's surface. The fly's body is tied with pale yellow or cream-colored dubbing, which helps it blend in with the natural color of the mayfly. The wings of the Light Cahill are tied with white or cream-colored hackle tips, and its tail consists of golden pheasant fibers or similar materials.
Step One

Begin the pattern by running the thread from below the hook eye to the hook point to establish a base for the wing to rest.
Step Two

We’re using a wood duck feather for the wing. Strip the tip of its fuzzy fibers, pinch the feather over, then secure it on the shank with the webby section extending past the eye. Be sure to trim the stem before moving on.
Step Three

Next, pull the forward-facing fibers toward the bend, then build a thread dam in front of the wing to push the fibers upright.
Step Four

Complete the wing section by separating the fibers with the bodkin, forming a wing on either side of the shank, then make figure-eight wraps to secure them.
Step Five
Run the thread to the bend, then secure a rooster neck feather’s tip on the shank with the webby fibbers extending rearward for the tail.
Step Six
Form a small dubbing loop on the thread, then advance from in front of the tail to behind the wing with overlapping turns for the body.
Step Seven
Tie another rooster neck hackle by its tip, on the shank's side by the wing, with the flowy fibers facing upward.
Step Eight
Make several turns with the hackle right below the wing, then in front of it before securing it and clipping the excess.
Step Nine
Complete the tying process by forming a quick head, then secure a whip finish. Now it’s time to target some low-light sippers!