Global FlyFisher. Fly from the pattern database -
All kinds of flies from all over the globe
The CDC & Elk family
Big Hole Demon
Twoface: A classical pattern originated back in the sixties - here adapted for Scandinavian sea trout fishing, but probably also useful for bass and other species as well as the brownies it was originally tied for. The fly is fairly easy to tie and we have made it even simpler.
See how to go about it here.
Read the article about the Susquehanna River
There are plenty of good crayfish patterns especially the Clouser and Whitlock flies. I keep my version very simple. For this fly, the "big fly for big bass" rule is the exception. A small crayfish (2 inches or less) with small pinchers is preferable to a larger imitation. Brown over orange and olive over yellow are two good color cominations.