Ya they are very variable, but the vast majority of garters in one area will probably look similar. The ornage one was the only real abberant one out of about the 20 or so I've seen there, so it's not like every snake looks totally different. Would be pretty sweet if they were all different though. I hear maritimes are especially variable. I saw a picture of 5 of them from the same island that all had a different pattern.

And about the spot, I really got lucky finding it. Its an area that was once dug up for a missle silo or something, and now its just all rocky and vernal pools formed. So there are thousands of frogs and tadpoles there, plenty of deep rock piles to hide and hibernate under, and there are no tall trees so lots of sun gets in. Racers, milks, nothern waters, ribbons, and garters all live there.