The giant Salmonflies of the Western mountains are legendary for their proclivity to elicit consistent dry-fly action and ferocious strikes.
This male was collected from the same cloud of spinners as this female and is probably the same species. I'm tentatively calling them both Cinygmula for now, but I'm really not sure about that ID yet.
This mayfly was collected from Rock Creek in Montana on August 17th, 2018 and added to Troutnut.com by Troutnut on June 13th, 2019.