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 picked up 2 balsa wood boxes with 36 flies each today. They both are made by Fuji. They are both size 12. Look like they are from the late 50's. Has anyone heard of this brand? Thanks guys!!!