I would suggest starting around Olympia, WA and follow US 101 along the Hood Canal around the north end of Olympic Pennisula. You may want to stop in Port Angeles and take the Black Ball ferry on a day or over night trip to Victoria, BC (passport required).
Anotherr side trip is to Neah Bay and Tatoosh head which is farthest west location in continental US.
There is several rain forest on the peninsula. We like the Hoh Rain Forest.
Kalaloch Natl. Park Campground is a good place to stay.
After crossing into Oregon, Ft. Stevens State park is an interesting visit. It was shelled during WW II.
Take your time and enjoy the trip. It may get a little damp. Fires should not be an issue on the west side of the Cascades.
What route are you taking to come west?
Bud
USAF Retired
Pace Arrow
2003 Chev Ice Road Tracker