Between Bullsnakes,an occasional pale milksnake, and plains garters, it would be useless. But in Ozzy's case, if he has an intergrade or a visitor from where ever, keying it down would help. Be glad you are not in Arizona at the four corners, sand snakes, leaf nosed, patch noses, and a host of others, so similar in coloration, and yet distinct species, keying was your only hope!! 3 species of sand snakes (shovel nosed), 2 species of leaf nosed, and 2 species of patch nosed. Sometimes their patterns didn't help much.