Hi,
This picture is probably not in enough detail to do the fly justice, but I am betting this will work well next summer on the Henry's Fork. I have tried several "regular" PMD patterns there and not had a whole lot of success. One that worked the best so far is the standard Craig Mathews PMD Sparkle Dun.
However, I have a feeling this paraloop version will be even more effective.
Other variations at: flyfishing99.blogspot.com