This is Tim Fox's pattern. It is "AWESOME". I tweaked these just a little. Using Firehole hooks, Tungsten beads and some UV here and there. The best!
We fish these nymphs mostly underneath our indicator rig. But many times we will swing these flies. We use 10 foot leaders down to 5x tippet swing them on floating lines or floating lines that have RIO's Versileaders on them.
Tied with real Woodduck Flank and Hungarian Partridge.