It was either a milksnake, or a kingsnake. Both of them have variations that resemble coral snakes. What area do you live in? I'm curious because coral snakes aren't often seen. If it were close enough to me, I'd be more than happy to go out and round it up and relocate if for you. And if it were a coral snake, at that size, it could have brought you a pretty penny, especially if it were a female.