You could go to Portland and back in a day trip but only under duress and with twins it would be awful. I am not in a position to offer hospitality at this time since I just have a teensy studio, but perhaps someone else can. Will you have a car? You really should see Mt. St. Helen's. The kids will love it. Otherwise, there is the Seattle Zoo, Seattle Center, Portland Zoo, ??? Grand Coolee is a separate trip. If y ou woud like a smaller but still powerful dam with great fish stuff, Bonneville is not far from Portland. if time is limited I would forgo Grand Coolee unless it is really important to you. mg