Darrell Black has worked horses since he was 12 years old. He has used the gentle giants to haul logs and pull hay wagons, mowing machines and other horse-powered equipment, and to plow and cultivate gardens for more than fifty years.

No more! Black has turned to mule power.

Black, now 66 and retired, came by his first mule four years ago — Ace, the result of a romantic encounter between a Mammoth Jack and…