Toughest Race on Earth: Iditarod

The 2008 Iditarod begins, and returning champion Lance Mackey already has a hitch in his plan.

The mushers cross the treacherous Alaska Range, facing obstacles, injuries and their fears.

With the Alaska Range behind them, mushers turn their attention to rest, a strategy all its own.

Mackey makes up for lost time, King devises a new plan, and Eskimo Nelson debates withdrawing.

Mackey continues to break trail for rival King but is catching on to King's game.

With Nome, Alaska, less than 100 miles away, Mackey, King, and Buser battle for the finish line.