Tiny Baetis mayflies are perhaps the most commonly encountered and imitated by anglers on all American trout streams due to their great abundance, widespread distribution, and trout-friendly emergence habits.
Dave Ruiter identified this specimen from pictures as Hydropsyche occidentalis.
This caddisfly was collected from the Madison River in Montana on June 30th, 2019 and added to Troutnut.com by Troutnut on July 17th, 2019.