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 specimen was one of several males fluttering around over the river late in the afternoon near the Twin Falls trailhead on May 14. It's pretty clearly the same species as this one collected on June 22 five years earlier.
I also collected a nymph of presumably the same species in the riffle beneath these dancing males.
This mayfly was collected from the South Fork Snoqualmie River in Washington on May 14th, 2022 and added to Troutnut.com by Troutnut on May 15th, 2022.