The giant Salmonflies of the Western mountains are legendary for their proclivity to elicit consistent dry-fly action and ferocious strikes.
This is a very rare mayfly in western Montana. The shape of the last gill is a key to its identification. I have collected this species in only one location.
This mayfly was collected from the Upper Stillwater River in Montana on May 5th, 2007 and added to Troutnut.com by Bnewell on June 26th, 2011.