The Light Cahill Dry Fly is a classic, it originated by Dan Cahill over 100 years ago. A basic imitation of a Pale Morning Dun or a Pale Evening Dun, the Light Cahill fly is a standard, that ranks right up there with the Adams. An assortment in all sizes is a must, in every fly box when out fly fishing for trout and other fish.
I would suggest using a 15 foot 3x leader size when using the Light Cahill Dry Fly. Add a little flotant to the wings and you will be golden!