Quote Originally Posted by CarlD View Post
King snakes aren't venomous, and eat other snakes ( including venomous ones), as well as rats and other vermin.
I was also thinking a King snake. I'm more familiar with the local species here in VA. I can tell you that one is non-venomous. All venomous species in the US have triangular heads except for the coral snake, which looks very different from that one. Also, I don't think coral snakes are native to CA.

Edit: took a quick look online, not a King snake. Looks like a racer as mentioned in the earlier post or a juvenile rat snake.