NW EAA Fly-In

We will be flying from Calgary to KAWO for the EAA fly-in for the fifth year
and would like to see some interesting sites around Washington, Oregon and
Montana. We've been to McMinville and the Spruce Goose Museum as well as
the blimp hangar and Museum at Tillemook.
The Boeing plant will likely be on our tour this year. Any suggestions as to
other interesting places or events to visit preferably near airfields
(aviation related or not!) appreciated. Our window is July 4th to July 13th.
Thanks!
Roland