If you define "near" as less than 10 miles, there are no CGs that close. Lake Pleasant is on a direct bus route with a stop right outside the main gate and is about 14 miles out. The ride into downtown takes about 35 minutes. I think that's an all-day route, not just a commuter run.
Since we lived in Bothell for many years and have adult children living in the area, we haven't stayed there. We moved to Anacortes almost 15 years ago, so our information on the Seattle area is a bit out of date.