Frosty, you may also want to contact your local 4H or FFA advisors, not sure of their availability in WA, but they can be a great help as tree id is a big part of the forestry competitions.
Also, my brother-in-law just got a book titled "Trees of North America", great info and photos in there. Pics of mature trees, foliage, bark patterns, and maps for most common areas.
Hope this is of some use.