Share this story Growing up in California, I first fell in love with mushing through a picture book about Balto, the famous Siberian husky. The true story—which I turned to again and again—began in January 1925. Children in the village of Nome were dying of diphtheria, and with every attempt to deliver supplies of antitoxin in the thick of an Alaskan winter—by plane, by train—ending in failure, an epidemic seemed imminent. With the community growing increasingly desperate, the local trappers proposed a far-fetched solution: a sled dog relay to mush the medicine from camp to camp. And though many dogs—and...