Urgent - found in basement - what to do...

[fl4ian]

I found an approximately 24 inch garter in the basement under a shelving unit that I was trying to move. I'm not sure how long he/she has been there.

I'm not sure what to do with him. I will release him outside if it is early enough for him to find someplace to hibernate. I have no experience with snakes, however, so I'm not sure if the temps are o.k. or not? I live near Columbus, OH (zip 43081).

If it's too late to release him, I'm willing to keep him over the winter, but will want to release him in the spring. Is this a viable option?

I don't want to keep him pent up and outside of nature, as he's a wild and not captive bred snake.

Any advice would be greatly appreciated, the sooner, the better. He's just sitting downstairs, and I don't want to lose track of him...

I've attached two pics of him/her (one is just a crop of the other).