[Zephyr]

Yes, it would be, but I don't recommend it with Thamnophis. The creamsicle corn snake is an example of inter-subspecies hybridization. The snake is quite attractive, but it is kept strictly in the hobby and is carefully preserved in bloodlines in the corn and rat snake branch of the hobby. With garters, creating intergrades would have to be done under careful observation, and if the offspring display any health defects at all or are not desirable in coloration then they should not allowed breed. All in all, if some one with a very controlled environment created an intergrade, Thamnophis hobbyists everywhere would have to be alerted, in the strain would have to be specifically monitored and cared for, so that no further integrations in the gene pool could happen.

It has crossed my mind a few times, but I'd prefer to breed for coloration within a subspecies. :P