Green’s Dictionary of Slang

(Can./US) a mule or horse-driver.

1913		Omaha Dly Bee (NE) 14 Sept. 13/3: The true skinner abhors the horse. Give him stubborn teams of big mules.
1923		N. Anderson Hobo 93: A ‘skinner’ is a man who drives horses or mules.
1925		Odum & Johnson Negro and His Songs (1964) 253: Skinner, skinner, you know yo’ rule, / Den go to de stable an’ curry yo’ mule.
1936		R.F. Adams Cowboy Lingo 199: The word ‘skinner’ further meant a teamster or freighter if he used mules or horses.
1947		Time 1 Sept. 17/3: But at least there will be no language difficulty, for these mules will have U.S. skinners [DA].
1953		T. Runyon In For Life 18: Wasn’t I a full-fledged skinner, able to crack a long line like a blacksnake whip?
1962		Ragen & Finston World’s Toughest Prison 818: skinner – A mule driver or teamster.
1991		(con. 1920s) O.D. Brooks Legs 207: They’re going to need a lot of mule skinners.