There is a lot of debate over this issue, whether Coastal Plains Milks Lamprolpeltis triangulum "temporalis" are a natural intergrade of Triangulum X Elapsoides or a true ssp. A lot of people in the hobby, myself included, believe that they are a relict ssp., and deserve recognition as such. There are a few people that work with locale and morphs of "Temporalis". Brad McKowen (StretchX), Tony Dongarra (TonyD.), and Ted Thompson of Susquehanna Ectotherms. As far as captive hybrids of Triangulum X Elapsoides, I know it has been done, but I have not personally seen the offspring. Tony has an article on Kingsnake.com that touches on the subject. I'll add a link below.
Here's a pic of my adult male St. Marys Co. Maryland
Coastal

And one of his '07 offspring.

I hope that helps answer your question.
-Phil
Link
-----
Work is the curse
of the drinking class!