Quote:
Originally Posted by
Eustace 
I've seen pictures of those trees that you can drive your car through along Avenue of the Giants. Looks incredible.
The trees that you (formerly) could drive through are the Giant Sequoias, which grow in the Sierra Nevada. They're the largest trees on earth (by mass). The Coast Redwood is the
tallest tree, but they're not as big around as a Sequoia. They're still utterly incredible! Really, once you get into Northern California you'll be in Big Tree Country all the way to Seattle, Douglas Firs, Sitka Spruce, Cedars, all grow larger than anything you've ever seen in your life (insert juvenile humor here). One day for Napa to PDX will pretty much require you to take the I-5 route (and it'll still take 10-12 hours). I'd open that up to 2-3 days, which would allow you to take 101 and make some stops along the way. There are lots of great little towns and coves on the Oregon coast as well; I especially like Coos Bay, Florence and Yachats (the Jewel of the Oregon Coast). You can cross over to I-5 at Florence, Lincoln City and Cannon Beach; I'd probably recommend the Lincoln City route as the most scenic, and it takes you through the heart of Willamette Valley wine country (pick up some Pinot Noir to drink at Tilth). In PDX I'd definitely stop at Crepe Suzette, and Genoa if it has reopened by the time you get there. My favorite Seattle picks are Tilth, Earth and Ocean, and Matt's in the Market.