Not everything is on the Internet! Many useful primary sources can be found in repositories (that is, archives, museums, historical societies, etc.) in hard copy. Everything you need to know about visiting a repository is on this page.
The Seattle area is home to these repositories:
Before you go, browse the repository's web page and look for these things to make the most of your research time:
Things not to do during your visit:
Things you should do during your visit: