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.
This one took an embarrassingly long time to identify, because the key I was following sent me on a wild goose chase when I interpreted the longitudinal dorsal stripe on the abdomen of this specimen as a "longitudinal pigment band." I've updated the key text on this site so that mistake isn't so easy for others to make.
This stonefly was collected from the Yakima River in Washington on April 24th, 2022 and added to Troutnut.com by Troutnut on April 27th, 2022.