Even I know about the King Ranch, and i live in the middle of nowhere!
I remember reading about it in the early 80's as a kid. I recall it being one of the most managed and studied white-tailed deer herds in North America at the time.
I even think it was used as a study site to determine optimal buck to doe ratios for whitetails, which back then was pretty novel study stuff.
I'm guessing it is still wild and unfenced deer, but with little exposure to humans and in an area with optimal mature buck to doe ratios that is what rattling will produce.