The famous nocturnal Hex hatch of the Midwest (and a few other lucky locations) stirs to the surface mythically large brown trout that only touch streamers for the rest of the year.
This is probably Isoperla petersoni, a very common Perlodid stonely in Alaska streams.
This stonefly was collected from the Kwethluk River in Alaska on July 9th, 2010 and added to Troutnut.com by Bnewell on July 3rd, 2011.