Well I did look at the Nymph pitcure and it looks Exactly like the
critter that is often referred to over here as a Hellgrammite.

Also some of the fishermen I know over here are more sophisticated
than to use generic lables like Dragonfly Nmyphs as Hellgrammites.
The link I referred you to is a knowledgable guy who knows what a
stonefly and dragonfly looks like.
Yup, We got Hellgrammites here. been here for 20 years or so that
I know of. Maybe imported with some of those fruit trees or other
Agricultural imports that have brought some "unwanted critters" to E. Wash.
in addition to Hellgrammites.