The locality is in terms mostly of specific countys. Sanderson, which is in Terrell County, TX is more likely to have blairs phase (from my experience), and a little more to the East in Val Verde county, you are more likely to find Alterna phase. But, it's not a 100% thing. There are both phases in all area's that are inhabited by the Grey bands. Marathon, Sanderson, Alpine, Lajitas, or Val Verde....if you are lucky enough to find a grey band it could be either phase. Locality really just accounts for the majority found.

And again, grey bands are reluctant to eat other snakes so if you HAD to house them together, im sure similar sized specimens would do fine if they are well fed. Roy Engeldorf (owner of the Outback Oasis motel in Sanderson) has kept them together on many occasions. As well as spoken to me about their lack of interest in cannibalism. Considering he deals with them on a pretty much daily basis, im sure it's not much of an issue.