If you can get into Seattle on weekends, there are definitely groups. Many of them cluster around Clarion grads.
I recommend joining Codex, and meeting some of the CW people who are in the Seattle area. You could also try hanging around the clarion west boards at
http://www.clarionwest.org, and see if there are Seattleites who might invite you into a group, or allow you to submit your work so that they can consider inviting you into a group. There may even be people around who have arranged groups in satelite cities like Kirkland.
I also recommend going to events at the SF museum, when they take place on weekends. The Clarion West parties that take place on Friday nights during the summer are free to all, and a good place to meet people who may be able to help you sustain a writing community.
Of course, I also recommend applying to Clarion West.