GRG Fly Tying - Clouser Crayfish 

This version of the Clouser Crayfish (recipe below) that includes the dark turkey back is a go-to pattern for rivers in Southwest Montana, such as the lower Madison below Ennis dam, the lower Yellowstone and the Missouri River where crayfish are present. This pattern is primarily dead-drifted, but has been swung effectively as well. Smaller sizes, such as 10 and 12 have proven to be most effective. Some also use this pattern to imitate late summer stonefly nymphs, such as the nocturnal stone.
Clouser Crayfish Recipe
Hook: Dai-Riki 700 Sizes 8-12
Thread: Gray 140 Denier
Antennule: Brown ringneck pheasant body feather
Antenna: Pheasant tail fibers
Legs: Remainder of body feather from antennule
Back/Tail: Dark turkey tail
Thorax and abdomen: Gray antron blend dubbing
Swimmerets: Ginger hackle