Bred for size (big and powerful), height (tall to work in deep snow), big feet with close toes (good on snow and hardy paws), thick coat (able to winter outdoors at -40), fluffy tails (protect their little noses when sleeping at -40).  We met the national park’s sled dogs at their kennel today.  They were pretty lazy since it was a sultry 65F and their ideal temp is -10F but Lucor did get up and sniff my fingers hoping for a treat.  The dogs pull about 3000 miles every winter to deliver materials to back country and to run patrols.  They get the summer off except to show off for visitors.  Visit the kennels if you come to Denali.  The dogs are great and their handlers obviously love what they do.  The dogs seem to love it too.  Even in the heat they clamored to be chosen to pull the practice sled for us.