I'm pretty sure that the state record BT's are south of Olympia and from the Olympic penninsula. That said, I've seen some monsters in the Skamania area. There might be a little cross breading going on, but some big Blacktails for sure. I've hunted BT from near the north border to the southern reaches. From my younger days I remember an area east of Quinault that had some monsters. Access sucked and the place stood on end. South of Randle also had some big bodied deer.
-Steve