The classic Light Cahill dry fly has been around for a hundred years or more. In Art Flick’s book, The Streamside Guide to Naturals and their Imitations, he states, “It is possible that more fish have been taken on this than on any other pattern of dry fly.”
And Mr. Flick says further, “It is probably one dry fly that all fishermen carry.”
Ray Bergman, another famous fly fisherman and fly-tyer, also heaps praise on the Light Cahill by saying, “If it was necessary to confine my assortment of flies to only two or three, this would be one of them.”
So, it is plain to see the tremendous respect that is paid to this humble little fly by all serious fly fishermen and fisherwomen.
From what I can ascertain, it apparently got its name from Mr. Dan Cahill, a trout fisherman who was given credit for stocking some of the famous trout streams found in the Catskills in New York.
I have always had good luck with this fly even when there were no hatches taking place. It can be tied in sizes, 12, 14 or 16. I prefer the smaller sizes myself.
At the risk of committing fly fishing heresy, I believe there is a better way to tie this fly than the traditional Catskills style.
But at the same time, I want to go on record as saying that I think that anything can be improved and one can always find a better way to do something, even if one is breaking with 100-year-old traditions that have been carved in granite.
In the traditional Catskill style of tying dry flies, the fly is kept afloat by using extra stiff dry fly hackle from rooster capes.