i can't speak to pnw plants specifically, but in the u.p of michigan i have eaten abundant ostrich fern & bracken fern. i Love ostrich fern's latin name: Matteuccia struthiopteris. & bracken fern is Pteridium aquilinum. i read a lot of blog posts & articles about safety/danger of bracken & chose to eat it so long as it was blanched & properly cooked. have taken some wonderful pictures of these delicious wild foods. i've turned them into vinegar pickles & canned them in soup mixes successfully.
here's a post i wrote about harvesting ostrich fern
& a daily harvest that included bracken fern