Snake Skin – Identification

Q: I found this snake skin in my garden. It makes me nervous to be working outside. Any ideas what it is?
A: I’m not expert enough to positively identify a snake by its shed skin but because this is so long, I first thought it to be either a black racer or a southern coachwhip.
But Jim Rodgers at Nearly Native Nursery says this is more likely the skin of a rat snake. It’s so long because a snake’s skin is wrinkled and doubled over the individual scales. When a snake wriggles out of its skin, the wrinkles are all straightened out.
All three of these snakes are non-venomous.
See