Garter Snakes of California
Ok I'm not a snakey person. I have trouble telling the different Garter snakes apart. Here are the ones I have photos of and what I think are their names.
All the garters are harmless to us, deadly to a wide variety of vertebrate prey including rodents, frogs, lizards and birds.
Thamnophis sirtalis fitchi - Valley Gartersnake
Probably a Thamnophis sirtalis fitchi - Valley Gartersnake, after eating a vole or gopher.