My list was from the DT, Barry. I left off at least half of what my "search" turned up, because the "river" connection was either minor or unclear, but I did include The Jam On Gerry's Rock.

I like your 1st two suggestions. LOL Probably from the Boy Scout (unofficial) songbook, eh?

Speaking of Amazon, GrassStains, there must be some songs about that one too.

Which reminds me, has anyone mentioned: "Song of the Volga Boatmen?"