Deep in the heart of the Alaskan wilderness lies the Iditarod trail, home to the last great race. In this competition, 96 teams will attempt to traverse more than a thousand miles with 16 finely tuned dogs as an engine. For some the goal is to win; for others surviving would be a feat all its own. BONUS FEATURE: EXPEDITION ALASKA: Alaska, America's last frontier, is a land of breathtaking diversity - mountains, ice fields, arctic tundra, mighty rivers and some of the world's most amazing wildlife. A team of some of the world's top scientists and wildlife filmmakers explores this remote and rugged landscape to document what impact global warming is having on the landscape and wildlife of this beautiful state.