That fly brings back memories of giant black pteranarcus husks all over the rocks, and the deep pool below High bridge on the Skykomish from the timber road side, late July on well-mended drift yielded me some great results. Those were some great summer days indeed!
We're talking a full 1" and change in size, and the chrome steelies would gobble em up if they were stationed there after ascending the whitewater.
I swapped one of my giant stones for a nutrina conehead with Martin J of worldwide angler several years ago, probably the last time I fished that pool that way.
Nice fly, thanks for posting it!