It won't do us any good to guess, but the acid test for the ultra mutation requires breeding to some form of amel corn. Even if this has hybrid origins (ie: gray rat snake), red-eyed stock or hets thereof must be in the equation.
I don't recall what gender you said you had, but if it's a male, breed it to a hypo A alao to see if it's a recessive mutation. The odds of capturing an ultra that was hatched from wild corns has to be something in the order of one in a million. If no-one is finding any others like your's in that area, capturing an ultramel has to be something far greater in odds against. Perhaps one in 10 million ; since it could only be produced from an albino being out there staying alive in the wild. It's more likely that a het albino would be part of a wild equation to produce ultramels in the wild, BUT that's still highly unlikely.
Not trying to diminish the amazement of your discovery, but if this does turn out to be an ultramel, it's far more likely that it escaped from someone. Even if it's mother was an ultramel that escaped from someone, it would have to join up with an albino or ultra or het albnio out there in the woods to produce ultramels. Pretty slim odds, unless it was bred to an albino in captivity and then escapted gravid. If you catch others like that in the same area, it would be interesting data, but still points to escaped origins. If you wanted to test for this potentiality, you must also capture novel corns in the area to breed to albinos, to see if hets for albino actually haunt that area.
Good luck and keep us posted,
Don
www.cornsnake.NET
South Mountain Reptiles