The giant Salmonflies of the Western mountains are legendary for their proclivity to elicit consistent dry-fly action and ferocious strikes.
Based on the pale longitudinal forewing veins (excepting the costals), dark middle terga, and genitalia (Burks '53), this specimen is P. adoptiva.
This mayfly was collected from Factory Brook in New York on May 9th, 2007 and added to Troutnut.com by Troutnut on May 18th, 2007.