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 spinner came from one of those huge swarms that make one just stop fishing and admire the spectacle. Not bad for a little-known species.
In the same swarm I collected a female and another male.
This mayfly was collected from Mystery Creek #249 in Washington on July 4th, 2020 and added to Troutnut.com by Troutnut on July 12th, 2020.