The giant Salmonflies of the Western mountains are legendary for their proclivity to elicit consistent dry-fly action and ferocious strikes.
This spinner appeared inside our car after a rest stop overlooking the Snake, so that's most likely where it came from. Two different keys place it firmly in Epeorus albertae.
This mayfly was collected from the Snake River in Idaho on August 23rd, 2020 and added to Troutnut.com by Troutnut on September 18th, 2020.