Hi, Tim - You may well be right. But the earliest known version, collected by Vance Randolph in 1942, says "Natchez" - this is the singer's recollection of a song she heard many years before. I think we can all agree that "Natchez" is not correct; but so far, we haven't found an earlier version.
I think I'd probably sing it as "Neches," because that's the most credible answer we've had so far - but would the writer have put both "Neches" and "Nueces" in the same song? I put "Natchez" in the Rise Again Songbook, because that's what's in the only version I could document from an authentic source. Finding a source earlier than 1942, would be a wonderful discovery.
-Joe-