Interstate 80 cuts through California's Sierra Nevada, and winter turns it into one of the most dangerous stretches of highway in the country. Blizzards can bury the road in minutes, so the film follows the people whose job is to keep it passable: roadside worker Joey, out on call at all hours, and firefighters from Station 97, including Jameson and Nathan, who cover 1,600 square kilometers of mountain terrain and answer emergencies ranging from jackknifed trucks to stranded drivers. Pete Labrance of the California Department of Transportation makes the calls on when to shut the interstate down entirely, weighing safety against the economic cost of closing a major freight corridor. On the opposite end of the risk spectrum are storm chasers Tod and his son Michael, who drive straight toward the same blizzards everyone else is fleeing, hoping to film the whiteout conditions up close. Real dashcam and on-scene footage carries much of the film, backed by interviews with the workers who treat the mountain pass as routine and the hobbyists who treat it as spectacle.