Alaska's famous furry citizens, the dogs of the Iditarod Sled Dog Race, are the most athletic canines in the world. From puppyhood to first days in the harness, from championship runs across a thousand miles of snow to years of pampered retirement, these spectacular dogs are indeed man's (and woman's) best friends. Did you know that …      • Alaska huskies are an ever-changing cross-breed of the smartest, furriest, and fastest dogs?      • Early US postal deliveries in Alaska were carried by sled-dog teams?      • Iditarod competitors race across more than 1,000 miles in just over a week?      • Heroic sled dogs have saved their mushers from icy rivers and gale-force blizzards?