In the Yaak Valley of northwest Montana, the worst fire season in living memory threatens the home of Tom Oar. In Alaska, Marty Meierotto flies into the heart of a vicious storm on his annual journey to his remote winter trapline. Turtle Island, Eustace Conway's refuge in the Blue Ridge Mountains, comes under threat from developers. And a new mountain man, lion hunter Rich Lewis, leads his dog team through Montana's Ruby Valley in pursuit of a deadly puma.

Marty Meierotto arrives at his Alaska trapline, but the unseasonably warm weather is impeding his plans. In North Carolina, Eustace Conway discovers two headless chickens in his henhouse, and begins a hunt for the predator responsible. In northwest Montana, Tom Oar discovers a grizzly bear has been prowling his property, while in the southern corner of the state, Rich Lewis frantically searches for his missing hound, Turbo.

Desperate for food after a grizzly bear ravaged his garden, Tom Oar embarks on a last-ditch deer hunt. Marty Meierotto begins to establish his winter trapline, breaking fresh trail in the uncharted wild. In the Ruby Valley of Montana, Rich Lewis pursues a marauding wolf pack that has slaughtered a neighbor's cattle. And in the Blue Ridge Mountains of North Carolina, Eustace Conway must deal with Scout, a careless intern with "a dose of city boy in him.

After a successful deer hunt, Tom rushes to prepare the meat before it attracts hungry grizzly bears. In North Carolina, Eustace takes on a grueling job that he needs to complete in order to make his first loan payment. Marty's mechanical problems return and leave him stranded in the cold Alaskan night. In Montana's Ruby Valley, Rich postpones an elk hunt when he discovers evidence of a lion poacher. Rookie mountain man Charlie Tucker begins his trapping season in Maine's Great North Woods.

Rich and his hounds track Rich's nemesis, the killer mountain lion Three-Toes, across the length of Montana's Ruby Valley. In Alaska, a young prot g brings Marty the new snowmobile engine he's been waiting for. Eustace races the winter frost to seed his field in North Carolina and in Northwest Montana, Tom receives a commission from a neighbor to build a primitive bow, with a deadline that puts his endurance to the test.

Logger turned Mountain Man, Charlie Tucker's luck takes a turn for the worse in the sub-zero North Maine Woods as a rookie mistake nearly costs him everything. In Alaska, Marty and Andy split up to cover more ground with the plan to rendezvous at dusk. But as night falls, Marty is missing in action. In North Carolina, Eustace puts his life on the line to help a neighbor in need, and in Montana's Ruby Valley, Rich Lewis sets off after a bobcat which has been eating his livestock, and the cat draws first blood, injuring two of his dogs before Rich vows revenge.

Marty rushes to make the most of an extra pair of hands. Tom's grandson comes for a visit but soon learns that there's no such thing as vacation in the Yaak. Charlie heads out on a hunt for shed moose antlers. And in Montana's Ruby Valley, Rich Lewis' dogs are hot on the scent of a mountain lion when their hunt takes a dangerous turn.

Rich's cougar hunt takes a dark turn in Montana. Marty competes with a wolf pack for food. Tom and Will race an oncoming storm that puts them in jeopardy. And in Maine, Charlie suspects sabotage.

Charlie spends the night injured and alone in Maine. In Montana Tom investigates signs of a predator lurking too close to home. Eustace rushes to raise money to make his loan payment. And in Idaho, new mountain man George Michaud tries to make a living running his dog sled through the peaks of the mighty Tetons.

Tom struggles to keep a deadly wolf pack off his land despite an injury. Rich tracks a large buck over tough terrain on his mid-winter hunting trip. Eustace makes some much-needed repairs and George is forced to make his way across the Tetons on foot across before bad weather hits.

In Alaska, Marty tries to capitalize on his recent string of good luck by building a second cabin at the far end of his trap line. Andy flies in to help but with temperatures dropping below zero, the backbreaking labor takes a toll. Tom is still recovering from a knee injury, but he needs a beaver tail to finish his latest commission. Tim and Nancy volunteer to head to the river and check Tom's traps for him, but it proves to be more challenging than they expected. In the Ruby Valley... with his prized stud horse, Rusty, threatening to escape and join a wild herd, Rich works on fixing up his corral along with his friend, Brad. But things quickly start going south. In Idaho, George Michaud has a run in with a thieving predator and in North Carolina, Eustace, Preston and Scout continue to work on the damaged tool shed roof, giving Eustace a chance to test Scout's evolving skills.

Tom heads down to Idaho to help his brother break a pair of wild colts. Charlie Tucker returns to action after his shoulder injury, and puts his recovery at risk on Maine's frozen Rowe Lake. Rich sets off on a cougar hunt but ends up having an unexpected run-in with a bear instead, and George continues his frustrating search for food by the Snake River.

In the Yaak Valley, Tom Oar teams up with his brother Jack to help return Jack's prized hunting falcon back to the wild. In southern Montana, Rich Lewis and his wife Diane need to move their cattle herd, but will the predators get to them first? Marty starts wrapping up a successful season, but the elements won't let him leave Alaska without a fight. Eustace and Preston realize they have to contend with coyotes who are putting their wild game at risk. And in Maine, rookie Charlie Tucker struggles to re-start his season after an injury left him with one working arm.

In Alaska, after spending the night under the stars in subzero conditions Marty struggles to get his snow machine out of a stubborn overflow. In the Ruby Valley, Rich takes his oldest dog, Brandy and youngest dog, Hatchet, out on a special training mission. Eustace and Preston set off on a crucial deer hunt, but are interrupted by loud intruders. In the Yaak Valley, Tom is called by his friend, Tim to help with a beaver problem and takes the opportunity to teach an important lesson; and in Maine, Charlie and Jim head to the frozen river to carve out 100 pound ice chunks for Charlie's root cellar.

The end of Montana's long winter is finally in sight. Tom and Nancy Oar are scrambling to get through the last of their winter works when a surprise call comes in from their family that will force them to make a difficult decision. In the Ruby Valley, Rich passes on some of his lion hunting knowledge to a greenhorn. Eustace takes an opportunity to pay down his loan by building a primitive canoe, but the work is well outside his comfort zone. Charlie continues to struggle with his injury, while racing the change in seasons to secure some final furs, and after a highly successful season, Marty bear proofs his cabin and prepares to head home to Two Rivers.

Winter has finally come to a close, spelling big changes for Tom, who bids farewell to an old friend and packs his bags for Florida. In the Ruby Valley, Rich grooms his youngest hound to take over the pack, but an influx of cougars finds the pup in over his head. In North Carolina, Eustace takes a dangerous trip down a rapid river to deliver the canoe he built to pay off his loan. In Maine, Charlie takes his furs to market and hopes to break even on his rookie season, while in Alaska, Marty enjoys a reunion with his family, then makes big plans for the future.

In the Season 4 premiere, unpredictable extreme conditions lead to the survivalists finding new ways to adapt.

Tom defends his home against the threat of a bear; Morgan makes a fatal miscalculation on thin ice.

Morgan gets stuck in the grips of an ice desert with no shelter in sight; Marty's return to Alaska's Revelation Mountains takes an unexpected turn.

Winter's uneven arrival creates mayhem in the mountains, placing Rich on the front lines of a new war against predators and pushing Tom to the brink.

Morgan climbs into the dangerous Alaska Range; Rich goes to war with the wolves.

Morgan walks into a death trap in the Alaska Range when a whiteout hits in an avalanche zone.

Marty finds an unexpected advantage; Rich starts a search for a lost friend.

Morgan stakes out his next meal to battle starvation; Marty finds an unexpected jackpot.

Tom's run of bad luck escalates, but he refuses to give up; Morgan closes in on his goal; Marty prepares for his family's arrival on the line.