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.
One picture of this specimen shows the spinner stage.
This mayfly was collected from Rock Creek in Montana on June 30th, 2010 and added to Troutnut.com by Bnewell on June 29th, 2011.