FOREST GROVE RANCH RIDERS
When we lived in the Portland area (10 years ago), we belonged to the horseback riding club Forest Grove Ranch Riders.  They have been going to the beach the middle of September (with horses) for at least 20 years.  We surprised everyone by showing up, it was great.  I even got to borrow a horse and ride.
Always plenty to eat, kind of pot lucks, everyone brings something and the club supplies much of the eggs and pancakes. Same for the dinners.