The giant Salmonflies of the Western mountains are legendary for their proclivity to elicit consistent dry-fly action and ferocious strikes.
This "specimen" is actually two different duns, one missing the middle front and back left legs, the other missing the terminal filament i.e. middle tail. I added them together by accident, but since they're the same species, stage, and gender, I might as well leave them together.
This mayfly was collected from the Big Lost River in Idaho on August 2nd, 2020 and added to Troutnut.com by Troutnut on August 18th, 2020.