NW3S has a Swap Meet every year at my place. In WA. This year we had about 30 cars signup and the owners and some family. It is a chance to exchange parts, buy, sell, etc. We have door prizes and BBQ or Pizza. In past years we've had over 50 people show up and have lots of folks drive from BC and as far as MT to attend. Next years will likely be around July/August.
Other meets in your area (NW) are dependant upon who wants to get involved to organize or help put together. The location is dependant upon the location of the majority of participants. In past years we have had cruises to Mt. St. Helens, Mt. Rainier, and so forth. There are also some mini-meets on occassion but those are small and sometimes prone to failure due to no shows.