I need help IDing this Garter Snake

[Venti]

Yesterday I found this little guy where I found Theif. He is not a Red-sided Garter Snake, so what is he?

Based on the snakes in my state, he could be:

Checkered Garter Snake - Thamnophis marcianus
Western Ribbon Snake - Thamnophis proximus
Plains Garter Snake - Thamnophis radix
And this is what I don't think he is:
Common Garter Snake - Thamnophis sirtalis

Pictures coming soon, but for now a description since my camera is recharging:

About 4 inches long, orange on the sides does not appear as on Thamnophis sirtalis, no yellow or white dots on head. Irregular black ticking near belly in a stripe that follows the cream colored stripe on it's back.

[Starling96]

Not sure
Pics help

[Venti]

I am uploading them to Photobucket right now, I think I am leaning towards Plains Garter Snake, but Steve would know for sure I think.

[guidofatherof5]

I'll do my best.

[Venti]

Here are the photos. He is really beautiful, and I would hate to have to let him go if he is a checkered garter snake, but I suppose it would be for the best. He is a bit nippy, he acts like he's three feet long opposed to a few inches!

You can click on any of the images to make them bigger if needed.

[aSnakeLovinBabe]

Eastern Garter snake... thamnophis sirtalis sirtalis.... a variation of the common garter snake, which includes the red sideds (the one in the common garter snake website picture), the easterns, and many other types of garters. Not all eastern garters have the orange on the sides of their necks, or spots on their heads, or even a lateral stripe! They vary infinitely but that's a pretty classing looking sirtalis.

[guidofatherof5]

My first impression is T.sirtalis not T.radix.
Would love to do a scale count(good side body close up) and a good side face close up. Any chance of that?

[guidofatherof5]

Where are you located? State?

Let's see what ranges in your area.

[aSnakeLovinBabe]

it's also entirely possible that he is a thamnophis sirtalis parietalis (red sided) that is totally lacking red.... they do exist! but he's one of those two... red sided, or eastern. I'm going to stick with eastern.

[RedSidedSPR]

He looks like a eastern, but yeah, redsided is possible, I've seen some with NO red. They look just like that...