The giant Salmonflies of the Western mountains are legendary for their proclivity to elicit consistent dry-fly action and ferocious strikes.
This specimen emerged indoors from nymphs I had collected, then partly molted into a spinner but got stuck along the way. I've included a couple pictures showing some of the spinner colors. It got a bit waterlogged after emerging, so the wings aren't in perfect shape, but it still represents one of two Baetids that were emerging and drawing trout to rise on the Yakima. Based on body size and shape, it is most likely the same species as this nymph.