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.
I collected this mayfly on the same trip as a female of the same species. After these photos it molted into a spinner. This is the form of Maccaffertium vicarium which anglers call the "Gray Fox."
This mayfly was collected from the Namekagon River in Wisconsin on May 28th, 2005 and added to Troutnut.com by Troutnut on May 24th, 2006.