Only in the Yukon: Yukon Quest

And they're off! One of the dog teams starts the 1000 mile race to Fairbanks.

From the Yukon Quest information page.

At the Top of the World, in the Yukon-Alaskan Interior, an epic event takes place every year that few people from "down south" have experienced. Covering 1000 miles between Whitehorse, Yukon Territory and Fairbanks, Alaska during the depths of the Arctic winter, the Yukon Quest is the "Toughest Sled Dog Race in the World."

The Yukon Quest Trail follows historic Gold Rush and Mail Delivery routes from the turn of the 20th Century. Once a travel highway of the Northern frontier, the trail comes alive each February with the breath of hundreds of sled dogs. Teams of one human 'musher' and 14 canine athletes, travel for two weeks, racing through some of the last pristine wilderness remaining in North America.

Look at the smiles. Those dogs are just happy to be running.