A sled dog is a working dog trained to pull a sled, a sliding land vehicle typically used for commuting in the Arctic region. Also called a sleigh or sledge (British usage) dog, they have been trained and used for this purpose for over 8,000 years. Until the snowmobile and semitruck came along, sleds pulled by these dogs were the only mode of land transportation in these areas. They were vital in transporting supplies and medicines to places otherwise inaccessible to humans.
Even today, sled dogs are widely used in Greenland and rural areas in Alaska, Canada, and Russia. They are trained from a young age to work with their pack and their trainer or musher. There are various recreational events and competitions where sled dogs participate with their musher.