Assateague Island's "wild" horses are actually feral, meaning they descended from domesticated horses. Every July young horses on the Virginia side of the island are rounded up for auction to raise money for the volunteer fire department on Chincoteague Island. Their journey includes a quick swim across a channel made famous by the children's book Misty of Chincoteague.
(Photograph shot on assignment for, but not published in, the National Geographic book The Wild Ponies of Assateague Island, 1975)