COLUMBIA, Tenn. -— In early April, the mules rule this city 40 miles south of Nashville. Long ears twitch in trailers that bump through the streets, braying rings out in Maury County Park, and residents greet strangers with “Have a good Mule Day.”

Mule Day marks the arrival of spring and brings together family and friends for reminiscence and cookouts, mule sales and shows, even a liar’s contest. For many, the highlight is a parade of mule-drawn wagons, pixieish beauty queens and waving politicians.

But for longtime residents, the event is also a window into the area’s rural heritage, and an homage to the humble beasts that turned the soil, gave a leg up to farmers and cemented the county’s reputation in the South for well-bred mules.