Kayak Point Campground in Snohomish County has a Yurt Village
Snohomish County, WA - Official Website
We've stayed there before many years ago & had a blast with friends renting the whole village out. Definitely would be good to check them out - they have electricity, but no running water etc.... You could stop by & chat with the rangers at the park - I assume its very different to live full time vs temporary dwellings of a campground.
Our yurt is temporary/off grid in Chelan Co. so its a different matter.