Gray Caddis Dry (tied by Norm Zimmerman) 

Hook: TMC 100 or 101 (#16)

Thread: Uni-Thread rusty-dun (8/0)

Body: Gray-olive beaver dubbing

Rib: One strand of pearlescent or green krystal flash

Underwing: 2-3 strands of pearlescent of green krystal flash

Wing: Dun yearling elk (dun deer hair is a fair substitute)

Thorax Hackle: Undersize medium dun

Tying Notes: Be sure that the thorax hackle is cut flush with the hook gap on the bottom so that the fly floats flush to the surface.  One last option is legs: one trailing wood duck flank fiber on each side of the body to represent trailing legs.