I'd be surprised if there were many "pure" sub-species left in the central U.S., given that the re-introduction efforts in the 1950's gathered deer from several different areas for re-stocking.
In the Ouachita mountains, most of the stocker deer came from south and central Texas. There was also a small remnant of native whitetails (probably Kansas spp.). Physically, they are noticeably different, with the "kansas" deer having a much longer frame and legs and darker coloration than the "texas" deer of the same age class. The "kansas" bucks, in general have heavier, taller racks, with good mass carried all the way to the end of the tines, the Texas bucks have good width, but not much mass, and here, at least, lack the tine length they are known for in Texas. Of course, both subspecies have been interbreeding, but even after 50 years there are populations that are still quite distinct.
