A cowgirl leads the daily "jingle" -- or roundup of horses -- at the A Bar A guest ranch near Riverside, Wyoming.
One explanation for the term connects it to the clinking of spurs worn by the cowhands, the din of which, at full gallop, helps encourage the horses to get a move on. Original image from Carol M. Highsmith’s America, Library of Congress collection. Digitally enhanced by rawpixel.