I just spoke to Don Soderberg recently on this very subject. He had an idea abou this, and I tend to think it is correct. Don suggested that the Kisatchies ARE a natural occurring intergrade, and that the biggest reason for his suspicion is the number and size of the eggs his females produce.
Emoryii snakes have much fewer and larger eggs than E.g.guttatas. In his experience, Don said that he had never had a Kisatchie produce more than fifteen eggs (I think he said his highest ever was thirteen, but I can't recall firmly). Of course, we all know that this is in line with creamsicle production numbers, but a corn will have 15, 20, 25 or more eggs on a regular basis.
Given that information, I am inclined to accept Kisatchies as a natural intergrade. However, I still think that the E.g.emoryii are just locale specific corns. So, in my opinion, it doesn't much matter.
Just my $.02 worth -- Darin