Update 2019-05-20: A more likely identification.
Definitely not a rattlesnake. Whatever it is, it chose poorly by showing up right in front of the dogs’ doghouse.
Don’t know which dog dislikes them most, maybe Yellow Dog.
Maybe Brown Dog.
Apparently not a rattlesnake, with no rattles and not the right kind of coloration.
My best guess is it is a Pine Snake (Pituophis melanoleucus).
It chose poorly.