Quote Originally Posted by AnnainOK View Post
In November, we rescued a garter snake (I'm not certain of the subspecies). She's done well over the winter, eating fish and shedding a couple times. Last Saturday we left on vacation, and upon coming home today, we found she had given birth to around ten babies.

It seems like a long time, but the only possible explanation was that she retained the sperm for several months; right?
Yes, certain species/subspecies tend to do that. I've had northwestern garter snakes (T. ordinoides) mate with multiple males during a single breeding season (spring or fall mating) and give birth to litters up to a year since their last mating. They can also produce more than one litter per mating.

Where did you find your snake? (what state)