I suspect that the Fiddlers Companion is in error. References are not always accurate. Our Okiemockbird seems to agree. The "pizen sarpint" ballad is usually known as "Springfield Mountain," although it may have attracted a few other names (like "Rattlesnake") along its varied pathway. Someone familiar with the old "Sourwood Mountain" fiddle tune might well have applied that name to the story at some time, but I doubt that "Sourwood Mountain" was the original location of the snakebite tragedy.

Sandy (a doubting Thomas)