Gary Camp, Bend Oregon
Man that is a though question with only a week. I would take I-5 From Seattle to Kelso and then West to Cathlamet and then take the Puget Island Ferry across the Columbia river to Oregon. Drive down hwy 101 to Depoe Bay for whale watching. Depoe Bay is a very interesting harbor. I would stay on 101 for the rest of the Oregon Coast to Ferndale, try to do the road from Ferndale Ca. to Petrolia and then Garberville with a side trip to Shelter Cove if time allows. Now you are in Redwood country and I haven't been South of Garberville. A word of caution Hwy 101 will be busy, it is mostly two road so allow more time than you think. you might want to skip the Puget Island Ferry and just take I-5 south to Portland and then 99 W through some of Oregons wine country to MacMinnville and then to Lincoln City Or and then South to Depoe. It took my former spouse and I 3 years worth of two week vacations to drive the Oregon Coast from Astoria to Garberville, but then we were also told we not only stopped to smell the roses we planted them first. We did vist almost every Oregon State Park facility on the whole coast (it may have taken 4 years it has been a while).