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).
A trout, and steelhead guide for many years in the Seattle, WA area. I've taught fly fishing schools for 30 yrs., and was the fly fishing technical advisor, and worked many days on the set for the very popular tv show, Northern Exposure.