They are the first line of defense on the last frontier, the roughly 400 state troopers who patrol the rugged and unforgiving terrain of America’s largest state — Alaska. One of the toughest law enforcement agencies in the nation, these officers often travel hundreds of miles in piercing subzero temperatures to uphold the law. Responding by land, air and sea — with backup sometimes days away — they face danger to protect the people and wildlife of Alaska.