Welcome to Oregon.
I don't know if you're willing to make the drive to the Portland area every weekend, but every Friday and Saturday night a lot of us on Stangnet meet at the Fred Meyer shopping center off highway 217 and Beaverton-Hillsdale Hwy.(Highway 10). Sometimes at the Sonic burger off Cornelius Pass south of highway 26 headed to the coast. And every Friday as well, the Dairy Queen in Aloha (Kinnaman and Farmington Rd. - further west down highway 10) has a cruise-in in the early evening.
If you're looking for other events down your way, check out driveonline.com and mustang-club.com. There might be some stuff posted in the event sticky here in the NW forums on stangnet.
So, what kind of car(s) do you have?