Question: Headin' Down Into the Mystery Below, is an album by American musician John Hartford, released in 1978, John Cowan Hartford (December 30, 1937 – June 4, 2001) was an American folk, country and bluegrass composer and musician known for his mastery of the fiddle and banjo, as well as for his witty lyrics, unique vocal style, and extensive knowledge of which location's lore?
Answer: Mississippi River