Out of the dark, frozen vastness in this Arctic valley, a chorus of barks and howls trumpeted the return of Green Dog’s oldest puppies from a dogsledding training run through the polar night on Tuesday afternoon.

Karina Bernlow and her husband, Martin Munck, run the outfit Green Dog, which has nearly 300 dogs in three yards. It’s located half a dozen miles from the main village in Svalbard, a Norwegian archipelago so close to the North Pole that winter is shrouded in uninterrupted darkness.

The working dogs, younger puppies and new litters played in the lashing winds that shifted thigh-high snowdrifts. This mix of husky and Greenland dog — a breed known for taller legs, big paws and thick fur — is especially social and thrives in the cold, Bernlow said. They don’t even fear the rare occasion when a polar bear ambles past the yards.