[GarterGuy]

Hmmmmm, I'll take a guess and say maybe a T.ordinoides? Definitely could use some better pics for scale counts and such, but if you've already kind of got between 16 and 18 (they can be a real buggar to count, especially on a squirmy snake) that ony makes me think more it's an ordinoides. Colour and pattern really remind me of them as well.
Roy