RRB Seattle chapter 'Pike's & Bikes' inaugural cruise in sounds like a good start.
...but what do I know, I live in Toronto.
I've enjoyed visiting your towns and outskirts plenty when I was still a Vancouver (B.C.) resident.
Good Luck with getting together guys.
Last year we did the Dead Baby Downhill. From Capital hill to Georgetown. It was roughly 1000 people bombing thru the streets with scooters blocking traffic. My girl took it easy and shared a flask of hooch once we cleared Chinatown with a guy on a tall bike. I will go again this year, would love to do it with a group of people. Here is there FB page. https://www.facebook.com/groups/167597283338402/
It takes place the 1st Friday in August, $25.00 to enter. Gets you a t shirt and a water bottle. The water bottle you can fill as many times as you would like with beer in Georgetown. This is how my son and I rolled.