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 was surprisingly straightforward to identify. The lack of a sclerite at the base of the lateral hump narrows the field quite a bit, and the other options followed fairly obvious characteristics to Clostoeca, which only has one species, Clostoeca disjuncta.
Described by Stark, B.P. (1995) A new species of Neoperla (Insecta: Pleocoptera [Plecoptera]: Perlidae) from Mississippi. Proceedings of the Biological Society of Washington 108, 45–49.