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 molted from this dun, or possibly one other dun I had in the same container that looked just like it.
This mayfly was collected from Mystery Creek #199 in Washington on July 28th, 2019 and added to Troutnut.com by Troutnut on July 30th, 2019.