On Virginia’s Chincoteague Island, wild ponies reign supreme. These compact, colorful horses with shaggy manes live in small herds of a stallion and several mares, combing the beaches and snacking on marsh grasses. Popular tourist draws, these ponies were made famous by Marguerite Henry’s 1947 novel Misty of Chincoteague. Each July, tens of thousands of people visit to watch hundreds of the horses swim across the channel from nearby Assateague Island, after which the equines are sold at auction to keep the population in check.

Despite their celebrity, the ponies’ origin is shrouded in mystery. Local lore claims the ponies are descended from horses that swam ashore following the sinking of a Spanish galleon off