I always questioned this Identification because this was one large yellow jacket that didn't match up with the sizes given for Polistes dominula in the descriptions I was finding on line. Or the pictures I was getting of P. dominula. I think that the small "bee" flying to the lower left in this picture might be a Philanthus gibbosus, a bee wolf. I make that stab at identification from the stripes on the abdomen so it is really just a guess on my part. And if so, the bee wolf's size is given at ~11mm or smaller. Does adventitious in the literature mean that P. aurifer is introduced? And if so then did it come down from BC Canada? In any case thank's for updating the identification.

Polistes aurifer is definitely native and well established in WA. The small wasp is also a vespid, but in a different subfamily (Eumeninae). It looks like a species of Ancistrocerus, but it is a bit difficult to tell from this picture.