I note that you're in Anacortes. There's a large number of RVs at Arlington and Paine, but you could try posting to http://groups.yahoo.com/group/WashingtonRVAV8RS/. We don't have one particular builders group, but there are several Seattle area EAA Chapters aside from Puyallup, Boeing Field, Harvey, and Redmond come to mind.
Chapter 326 at Pierce County Thun Field in Puyallup has over 60 RVs either under construction or flying. Very active build chapter and a good group of people.