Just about anywhere in Western WA has coyotes, the big trick is seeing them before the know you are there. I cannot think of anywhere I've hunted grouse, ducks or deer I haven't seen coyote sign, or paved roads that I haven't seen one dead on. Just find public land and scout out some good stands, come back and sneak in and start calling.
Remember you cannot fool a coyotes nose or eyes so make sure that the aproach a coyote will take does not put him down wind of you, cover your hands and face and keep movement to a minimum. Have fun and slay a few.
AWS