The famous nocturnal Hex hatch of the Midwest (and a few other lucky locations) stirs to the surface mythically large brown trout that only touch streamers for the rest of the year.
This is the first of it's family I've seen, collected from a tiny, fishless stream in the Cascades. The three species of this genus all live in the Northwest and are predators that primarily eat stonefly nymphs Merritt R.W., Cummins, K.W., and Berg, M.B. (2019).
Sorry, Dave. I'm not good at Zygoptera. Unless someone is familiar enough with this genus/species that they can recognize it at a glance, it might require being able to see the labium and the lateral aspect of the gills (the things that fly fishers call "tails" on damselfly naiads).