Pacific Northwest (and beyond)
Archives West - Archives West provides descriptions of archival collections in Alaska, Idaho, Montana, Oregon, Utah and Washington. Online and offline collections are included.
Seattle and Washington
History Link - "The Free Encyclopedia of Washington State History" is a great starting point for any questions about history in Washington.
MOHAI - The Museum of History and Industry has excellent online photo galleries of Seattle and Washington.
Washington State Digital Collections - Links to digital collections held at institutions throughout Washington.
University of Washington Special Collections
Washington State University Manuscripts, Archives and Special Collections
Gonzaga University Archives and Special Collections
SPU Digital Commons - Photos and publications from the history of SPU.
Oregon
Oregon Historical Society - Collections on the history of Portland and Oregon.
Oregon Digital Library - Links to digital collections held at institutions throughout Oregon.
University of Oregon Special Collections & University Archives