The giant Salmonflies of the Western mountains are legendary for their proclivity to elicit consistent dry-fly action and ferocious strikes.
My blurry photo at first makes it look like there might be a distinct notch in the subgenital plate of this specimen, but that's not the case -- just a poor photo. That's important to the ID.
This stonefly was collected from the Gallatin River in Montana on July 2nd, 2019 and added to Troutnut.com by Troutnut on July 18th, 2019.