They are the first line of defense on the last frontier, the roughly 400 state troopers who patrol the rugged and unforgiving terrain of Alaska. One of the toughest law enforcement agencies in the nation, these officers often travel hundreds of miles in piercing subzero temperatures, where any person they encounter could be armed. With rare access, National Geographic follows the Alaska State Troopers capturing a mixture of raw nature and criminal activity throughout the Alaskan wilderness and its remote villages.