It is indeed played during S-1 E-11 "Jewel's Boots Were Made For Walking," the end trailing credits of "Deadwood."(2004)

Snake Baked A Hoe Cake
(uncredited)
Performed by Mike Seeger (1933-2007)
(Younger half-brother of Pete Seeger and older brother of Peggy Seeger, Brother-in-law of Ewan MacColl, created "The New Lost City Ramblers" in 1958).
(source IMDB)

I am watching "Deadwood" for the first time.

Sincerely,
Gargoyle

My attention span for movies is about 20 minutes...but with perseverance I am getting through two episodes a week.