This is an amazing museum in the middle of the very rural Willamette Valley south of Portland, OR.
I stopped for most of a day and a night staying in my truck/camper in their parking lot.
The "featured" plane is Howard Hughes' giant "Spruce Goose" that was never completed and only did one test flight up to about 10m (30ft). It was moved from southern California by barges.
This place is well worth the visit.