For more than 60 years, Sirius has been entrusted with patrolling northeast Greenland's 8,699-mile coast. The 12-man team visits each inch of the cracked and ragged coastline at least once every five years, formally supporting Danish sovereignty under international conventions. Sirius is the world's only military dogsled patrol. The job -- low pay, no holidays -- entails journeying with a partner and a dog team for 26 months and more than 5,000 miles. Injuries are virtually inevitable, as are hunger and exhaustion and frostbite. Team members are stalked by polar bears. There's no chance to visit family or friends, no opportunity to go on a date. They never even get to see a tree.
Images courtesy of Fritz Hoffman and National Geographic. Captions courtesy of National Geographic. Images can be seen in the January 2012 issue of National Geographic magazine, on newsstands now.