Thing is, while the river may be made up, there is a town called Nachedoches in Texas, so he didn't make up the whole thing. I think I've spelled it right, I will check.
I had an aunt who lived there, and when I had to write her as a child, I was always amused by the unusual name.
Blessings,
Barbara, who learned this from Faith, too, and the way you fit in Nachedoches is you drop the word 'River'; i.e. "And down in Nachedoches, there's girls by the score..."