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.
These larvae were all over the submerged rocks in a small mountain stream in the Washington Cascades, tightly adhering to the rocks in their flat, half-disk-shaped cases.
This true fly was collected from Mystery Creek #249 in Washington on July 25th, 2019 and added to Troutnut.com by Troutnut on July 27th, 2019.