I know there is the Barter-Faire up in Tanasket, Wa. It is usually in October, annually. I believe you can google it, there is a site for it! I am actually hoping to go next year, I've wanted to for many years....don't forget your tie-dye!
June Faire, which is put on by the S.C.A, which is renissance renacting, is the very first weekend in June up in Port Gamble Washington, Kitsap county. From the Seattle area take HWY 16 (or the ferry) to bremerton, get on Hwy 3 (hwy 16 becomes hwy 3 in gorst) and follow north. It will become a 2 lane hwy just past poulsbo, then a 2 lane road as it enters port gamble. You cant miss the faire, one side of the road is all encampments and mideviel tents, the other side is merchants, renactments, armoured combat, and so much more. My group, the Myrmidons (the guys are in red Chitons and lether armour with a red medusa/gorgon head on the shield) fight heavy combat there every year. Check out our baronies website for a list of upcoming events that are open to the public: http://www.dragonslaire.org/