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.
Based on both range maps and key characteristics, this larva is either Hesperophylax designatus, Hesperophylax alaskensis, or Hesperophylax occidentalis. However, the species key in Parker & Wiggins (1985) cannot separate these species as larvae.
This caddisfly was collected from the South Fork Snoqualmie River in Washington on June 13th, 2019 and added to Troutnut.com by Troutnut on June 15th, 2019.