The mushers and their dog teams will spend about the next eight days traveling across a thousand miles of Alaska wilderness in a sled, all trying to be the first musher to reach the old Gold Rush town of Nome.
There are six former champions in the race, including last year's winner, 49-year-old John Baker of Kotzebue.
Prior to the start of the race Iditarod officials added one mile back to the length of the course.
Last month, they decided to remove the Happy River Steps, a dangerous set of switchbacks between the Finger Lake and Rainy Pass checkpoints.
However, officials recently said the alternate route was no longer a better option because of snow, and they went back to the Happy River Steps route.