The above response is inaccurate.
Nickajack is not a reference to a poker game, rather, it is an area of the Appalachian foothills, the woman in the song is likely turning up her nose to that area. Coyote is referencing a human smuggler, generally south of the border.
Three dead in a crash on the number 4 with witnesses below and up high is a reference to a car crash witnessed only by God and the Devil (below and up high), no one else was around. When he asks whose will be done-he is a sinner because he questions that fact that anything besides God's will be done.