One of the famous flies from the stable of Blue Ribbon Flies in West Yellowstone. I did take the liberty to change a couple of the materials though. Get out and give it a try. You can order them right off the net from their catalog if you wish.
Up Right Trico Spinner Variant
Hook: TMC 102Y, Sz: 19
Thread: TMC 18/0 White
Tail: White Micro Fibbets
Post: 1/8 Strand McFlylon
Thorax: Stalcups Fine Trico Dubbing