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.
For details about the tentative identification of this male dun, see the page for associated male spinner, captured from a mating swarm in the same location and at the same time as this dun was emerging.
This mayfly was collected from the Cedar River in Washington on June 30th, 2021 and added to Troutnut.com by Troutnut on July 2nd, 2021.