Well I joined Eastern Washington Genealogical Society in 1991 and that is the largest genealogical society in the area. I am also a member of another close by genealogical society, the Whitman County Genealogical Society. The last Washington genealogical society close by is the Northeast Washington Genealogical Society. Actually closer to me than either of these Washington societies is the Kootenai County Genealogical Society, in Hayden, Idaho. I could not find a website for them, and they are kind of odd for our area as they are snowbirds and close in the winter and meet all summer. EWGS is just the opposite, closed in the summer and meets all winter. All of these have excellent education classes, but I seldom get to any but those that EWGS does.
I also belong to a couple of other genealogical societies, the Great River Genealogical Society in Quincy, Illinois, and the Grundy County Genealogical Society in Trenton, Missouri. Both of these are from areas where I still have some research to do.