Help me identify this guy please

[eskimoroll]

Hi everyone,

I came across this small snake recently and am having trouble indentifying it, I was hoping someone from this group could help out. He was found near Sorel, Quebec bathing on a rock near a lake. He is very high strung and nervous. From the pictures I studied, it seems to be a mellanistic eastern garter snake...but the diamond patterns around his head are the only characteristic which I haven't matched on any image found on the web.

Any help would be appreciated, I just want to make sure he is not venemous, or an endangered species.