Columbia, Tennessee bills itself as the "Mule Capital of the World" and has held an official "Mule Day" each April since 1840. Today, celebrations have grown into a week-long fair, featuring parades, concerts, mule shows, flea markets, athletic competitions, and more.
The organizers arranged for a pictorial postmark, and I sent for it. My cachet uses a digitized photograph of two lovely ladies — Ethyl Maxwell and Evelyn Morgan (Abernathy) — posing at the 1939 Mule Day. (For the record, the mules also had names: Betty Grable and Mary Pickford.)
I also was not especially fond of their official logo, so I created my own and positioned it in the lower-left: the face of a happy mule, ears erect, surrounded by a circle and the words "MULE DAY 2016" in a horseshoe-style font.
The stamps are "Greetings from Tennessee" from the Greetings from America issue (Scott 3602) and a booklet single of the 1978 Roses issue (Scott 1737).
Instructions for ordering the Muletown Station postmark (through August 18, 2016): http://collectpostmarks.com/postmarks/muletown-station-columbia-tn-2016-03-01/
Mule Day official home page: http://muleday.org