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.
Here's a classic March Brown dun from the Catskills.
This mayfly was collected from the Neversink River in New York on May 20th, 2007 and added to Troutnut.com by Troutnut on May 21st, 2007.