Fabric Depot for sure. It's not so much a quilt store as a great place to buy all kinds of fabric.
Definitely stop by Finally Together in Lebanon. It's not far off of I-5, north of Eugene, and it is definitely worth a visit. It's a huge shop full of beautiful sample quilts, lots of beautiful fabrics, and if you buy the last on the bolt you get a great discount. Tell Paula hello for me. (I used to live near there, in Albany, and I go in every time I go back to Oregon for a visit.)
Then there's another great store in Jefferson, just a little further north, Purple Frog.
Are you going to the Sisters Outdoor Quilt Show? It's the second Saturday in July and definitely worth a visit. I'll also be driving up from Lake Elsinore sometime in July. Maybe we'll bump into each other along the way?