Definitely worth a trip through the fields and vineyards of Yamhill County. This may be the best-stocked store I've ever seen, from yarn to notions to serious equipment for spinners and weavers. Make a day out of it and visit the wine tasting room in Carlton!
Fiber Nooks & Crannys manages to pack a lot of yarn into a small space. The emphasis is on natural fiber yarns in the mid price ranges; she also has a decent stock of needles, accessories, books and patterns. The owner, Michelle, is extremely helpful and relies on customer feedback to guide her stock selections. The store offers knit and crochet nights, classes and other events, as well as charity knit-alongs.
Great store for sock knitters; they stock both Socks that Rock and Mountain Colors Bearfoot yarns in many colors, among other brands, and have a good selection of small-gauge DPNs in various materials.
Lovely people, lovely yarn, lovely little store. I especially like that they manage to stock full color ranges of a given yarn, and if you buy hanked yarn, they offer to wind it for you.
Besides a large selection of dyed yarns, Woodland Woolworks offers undyed yarn in many different weights and fibers by the cone, and allow you to wind off as much as you need. Yes, the service can be a little laissez faire, but if you know what you want, it's the serious fiber artist's heaven.
That should, of course, have said "The Weaving Works." I do wish this system allowed one to edit or delete one's own comments...