First time poster. I just found this site today.
My wife and I will be making a similar trip, (SFO to SEA) for 10 days this coming September as well. We will travel the coast for the majority of the time, with a diversion to Crater Lake via US 199 and State Route 62. We will head back to the coast via State Routes 138 and 42 to Bandon.
As part of what Donna above referenced as "and so much more........."
I was informed that Jedediah Smith Redwoods State Park is worth seeing, especially the Stout Redwood Grove, a part of Jedediah Smith State Park. It is right off US 199 a few miles east of Crescent City and US 101.
Here's a description from the Stout Grove link above:
Stout Grove is the world's most scenic stand of redwoods. It's not all that large, and it doesn't have the biggest trees, but for sheer photogenic beauty nothing beats this extraordinary grove on a sunny afternoon....
The grove has a remarkably hushed and serene environment. Sounds are damped out by the thick, spongy layer of needles on the ground. What's more, the grove is hidden away off the normal tourist routes and busy Highway 101 is miles away.
Once back at Bandon, we will continue north along 101 till we reach Lincoln City. Heading inland to Portland with a destination of Mt. Rainier and then finally on to Seattle. I want to visit the Evergreen Aviation Museumin McMinnville, OR. There is a very famous large wooden airplane housed there........
I found that Thrifty had the best rates of any of the major rental companies for a one way from San Francisco to Seattle, unlimited mileage. I joined their Blue Chip program to avoid the lines at check-in.
Note to roxycat: Where ever you are along the coast at sunset, stop to enjoy the view! I traveled from Eureka to Portland several years ago. I spent the night in Bandon, and will spend the night there again so that my wife can enjoy the view.