Denali rarely has enough snow to run dogs with a sled until early November, but training must begin much sooner. The mushers hook six to ten dogs to an all-terrain vehicle or a four-wheeler and drive three to four miles around loops in a park campground. Though not nearly as peaceful as sled runners gliding smoothly over the surface of snow, these training runs are crucial in providing the exercise necessary to rebuild the dogs’ muscle and endurance, which have diminished during the summer months. It’s also good preparation for the heavy sleds they will pull later in the winter.

As soon as there’s enough snow, the sleds are brought out and the real winter excitement begins. During November and December, temperatures drop to the minus-20s, -30s, and sometimes -40s, and daylight lasts only four hours. Late February and the month of March are the height of the winter season for trips into the park, both for visitors and park personnel working on research and other projects. At this time of year, dog teams spend solid weeks on patrol. At least one team, and often more, are based at the Wonder Lake Ranger Station deep inside the park.

By early April, the temperature rises, the river ice diminishes, and the snow turns slushy. Now the teams return to kennels at park headquarters. It is time to give the dogs a break, put away the harnesses and other winter gear, and prepare for another summer season in Denali National Park.

During the summer, when it's too hot for serious exercise, the dogs spend their days running the demonstration loop for kennel visitors. In the long summer evenings, volunteers take the dogs for “walks,” during which the powerful huskies drag their companions down the edge of the park road. This popular volunteer program not only provides the dogs with exercise and a chance to get away from the kennels, but also forges special bonds between the dogs and their walkers, bonds that sometimes last for years.