I've hunted Phelps and Maries counties which are just east of that area and Johnson county which is northwest; 140s are really very common. A quick scan of the archery records by county shows plenty of 160s in that general area.
I'm of the opinion that Missouri is a bit of a sleeper state; partly because there's so much focus the neighboring states of Kansas, Iowa, and Illinois. Folks will drive right through MO to get to one of the other states, but some dang good ones hit the dirt there year after year.
