Musher Al Hardman of Ludington, Michigan, arrives in Elim, Alaska last year during the Iditarod Trail Sled Dog Race. Elim is about 123 miles from the finish line. (Andy Klevorn/AP Wide World)

Running the more than 1,000-mile Iditarod course is grueling for both mushers and dogs. It's exhausting, challenging, and unpredictable. The mushers' goal is to keep their dog teams moving through the starkly beautiful Alaskan landscape, and to stay ready for anything.

Q: How many hours do you actually race? What do you do during race breaks?
Martin Buser: During the breaks, we tend to the dogs. We make sure they are comfortable, feed them, rub them down, and check their feet. Then we feed ourselves and try to get some sleep. I sleep an average of two hours out of every 24 hours. That is one of the biggest challenges of the race.

Q: When you were in the Iditarod, did you ever reach a point where you felt like you might not finish?
Paulsen: I never thought I would finish. I didn't see how it was possible for me to finish because I was a rookie. The Iditarod really changes you. It was a life-altering experience. That was 15 years ago. I realized that the things I thought were important in life were not. Looking at the horizon and living life to its full capacity is important—not wasting your time.

Q: What would you say is the most challenging or scary part of the Iditarod?
Martin Buser: Terrain-wise, the first 200 miles are the most difficult. Endurance-wise, it's the last 200 miles because we get so tired. We try not to think about how tired we are. We take catnaps here and there, but we know the finish line is near and we hang in there. My greatest fear on the trail is what we call "overflow." Sometimes the pressure of a lot of snow on a frozen lake or river causes water to rise up around the sides, and then there is open water on the trail. Water and below-zero temperatures are a very dangerous combination for people and dogs. The dogs learn to go around it if they can, or go through it if it is not too deep. But it is very unpredictable.

Gary Paulsen: The fear when you cross open water is the scariest part of the Iditarod. You go over lakes, rivers, and 75 miles of open Bering Sea. Saltwater ice has a strange feel and it is hard to judge its stability. And this is scary because you know how terrible it will be if you fall through the ice.

Q: What kinds of animals have you seen on the trail?
Martin Buser: I have seen lots of animals or signs of animals. Once I saw in the snow the traces of a wolf pack but never saw them in the flesh. I have seen a wolf on a rare instance. We see moose, sometimes too close up as they compete for the packed-down trail in deep-snow years. Foxes and coyotes are sometimes seen off in the distance. Once my team chased a herd of buffalo in the snowless Farewell Burn area—although I didn't see much more than a cloud of dust. That was a wild ride! I've never seen a bear on the trail. In fact, most animals maintain a distance from dog teams.

Q: How did you feel the times you won the Iditarod?
Martin Buser: Of course, you feel like a proud dad! I guess every time is different, but it always feels very gratifying. It's a very proud moment. It is also very humbling because we realize we could never do it without the dogs. They are the true heroes of the trail. I know the dogs understand the victory. They are proud of their owners, and they look twice their normal size. They know exactly what they have accomplished. When I won the Iditarod the first time in 1992, it was just a great reward and a big relief that after so many years of training, we managed to do it. It was a great feeling after working so long for something. Persistence pays off.