This season opens as a polar vortex sweeps across the nation and plunges America into a brutal early winter. Tom Oar is behind on his winter preparations because he's spending time with family in Florida and facing a possibly life-changing decision. Will he sacrifice leaving the mountain man lifestyle behind to live closer to his family? In the Ruby Valley, a bloody encounter with a mountain lion leaves Rich Lewis's lead hunting dog Brandy in a life or death situation, and could end her career forever. Marty Meierotto takes advantage of a break in the harsh weather to embark on his annual trip to the Great Alaskan Range, but this year instead of leaving his wife, Dominique and their daughter Noah behind he's taking them with him. And in New Mexico's rugged and relentless High Desert, we meet Kyle Bell who is teaching his son the dying ways of the mountain man lifestyle. Kyle and his son Ben scramble to save a herd of bison from a fast approaching winter storm.

As the worst winter in decades rages across the nation, the Mountain Men must fight to stay on top of the food chain. In the Yaak Valley, the growing wolf population comes knocking on Tom Oar's door, and quickly turns into a blood feud. In Alaska, Marty Meierotto's traps are coming up empty, causing him and his family to regroup and figure out how they're going to survive the season. In the Ruby Valley of southwest Montana, Rich Lewis bags enough meat to survive the winter, but his battle has only begun as hungry predators catch the scent. In North Carolina, Eustace Conway struggles to bring a 100-year-old sawmill back to life to keep his property in the black. And in New Mexico's Cimarron Valley, Kyle Bell puts his 10-year-old son's mountain man skills to the test on his first hunting trip.