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 pretty clearly keys to Kogotus, but it also looks fairly different from specimens I caught in the same creek about a month later in the year. With only one species of the genus known in Washington, I'm not sure about the answer to this ID.
I left Chitina around 8pm after 12 hours dipnetting and 2 hours cleaning fish, then drove north toward home for 4 hours before stopping to "car camp" at the same Gulkana River access I photographed on my trip down. First, I took a few minutes to work on my nighttime river photography under the full moon.