Second, I might reconsider the route you've choosen... I would work west from Portland by the transit train MAX to Hillsboro and set yourself up some nice lodging in Forest Grove. Get a good night's rest, a hearty breakfast (Maggy's Buns?)
That is an interesting suggestion!
We could cycle west from Union Station to Forest Grove. (I'm leary of trying to take a fully loaded touring bike with tent, sleeping bag and 4 panniers onto rapid transit during rush hour) Then the next morning we could head west to Cape Lookout State Park via hwy #6.
Thanks for all this great advice. All of you fellow cyclists have been very helpful.