Yes, it is a type of ratsnake found in Texas, and Louisiana, actually a type of corn snake. It has been proposed to be a new species, Pantherophis (Elaphe) slowinskii, Slowinski's corn, but many have not accepted the new designation and, like myself, call it, P. guttata slowinskii. It is a subspecies of corn snake and I doubt if any GA wildlife official would be able to tell the difference. I would check with them to see if the official taxonomy makes a difference to them, otherwise they'll just see it as a corn snake.
I would suspect it would be easier to establish the Great Plains ratsnake as a different species of ratsnake than the corn. They are easier to distinguish, imo, and would offer you a great variety of possibilities to work with. I work with the southern form, P. guttata meahllmorum, and the western form, P. g. intermontana. They are both quite distinguishable from the corn. The Northern Plains ratsnake, P. g. emoryi, could also be used.
Many think Emory's ratsnake is a separate species from the corn snake. You could use, P. emoryi, for the current taxonomy, if you wanted to. There are many variations, mutations, morphs, etc, also. Hybrids bt. emoryi x guttata wouldn't necessarily be a corn snake either. If I were you I'd test the laws to see what's allowed..a good project. I think it would be pretty easy to prove your Great Plains ratsnake was not a corn snake and I sure would try. GA can only list guttata. They can't list a snake that doesn't exist in their state and they have no jurisdiction over. You could win that one in court 
TC
Here's a few examples of meahllmorum...

Head shape...

Ventrals are often plain colored in "meahllmorum"...

The photo below shows a light colored hybrid bt. a corn and a "meahlmorum". The other two are Brazos Island ratsnakes...
