Plants of the Pacific Northwest by Pojar and McKinon is one of my favorites. Michael Moore's Plants of the Pacific Northwest is good as well.
Blessings
Linda

Indian Herbalogy of North America by Alma Hutchens

MicMac Medicines, Remedies, and Recollections by Laurie Lacey

Medicinal and Other Uses of North American Plants: A Historical Survey with Special Reference to the Eastern Indian Tribes by Charlotte Erichsen-Brown

Earth Medicine-Earth Food (The classic guide to the herbal remedies and wild plants of the North American Indians) by Michael A Weiner

And this last one, which an elder recommended to me and it's come in pretty handy, I might add!

Health from God's Garden: Herbal Remedies for Glowing Health and Well-Being by Maria Treben

Local is best .... When you are participating with your bioregional plant life forces, the medicine or power can have more benefits for you, as you are part of the same bioregion; but as always you must maintain and foster a positive relationship with the plant people in your area.

You can contact a local wise man and herbalist -Michael Pilarsky A.K.A Skeeter
He has published a few books and they are available on his websiter Friends of The Trees Society.
The one I have which is really thorough focusing on local and sustainable wildcrafting is : Growing & Wildcrafting Medicinal Plants in the Pacific Northwest.

I also highly recomend the books that are listed above. It is good to have multiple perspectives and books when you are learning to identify plants for their medicinal uses. Have fun!

Also Ryan, herbalist Carol Mcgrath is in your area and she is quite inspiring. I am not sure how to contact her. For several years I connected with her at the Pacific Northwest Womens Gathering (no longer in existence) and really enjoyed what she had to share. Perhaps you can track her down.
Blessings
Linda