In Anchorage, Alaska, on Saturday, the "Last Great Race on Earth" begins.
Sixty-seven sled dog teams will start the 998-mile Iditarod race across the barren, frigid and unforgiving land. In this year's competition, there are a handful of first-time racers — but those aren't the only rookies.
One is veterinarian Greg Reppas, whose job is to ensure the dogs are healthy throughout the race.
Days before the race, Reppas squats in a snowdrift in Wasilla and checks out Leo, one of the 16 dogs on this team that will start the Iditarod.