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 went to great comical lengths to swipe this spinner from the air with a little aquarium net I carry with me while I'm fishing. Siphloplecton basale spinners fly fast and high over the riffles, and there are never very many of them, so they're difficult to catch.
This one's stunned or freshly dead in the pictures, because the water in my photographing tank was a bit too warm for him after being under the bright light for a while.