Helicopters leave the eight explorers on a snow-capped summit. The men split into three groups and approach a 300-foot cliff, descend a ravine and traverse eight miles of the Triumvirate Glacier.
The eight explorers are on the fourth leg of their expedition and are struggling to stay afloat on the Talachulitna River. With currents rushing at dangerous speeds, it's no easy feat to navigate the frigid waters.
The explorers brave the dangers of Alaska's "Bear Highway" only to find themselves stranded and fighting to survive Mother Nature's fury on the shores of Katmai Bay.
The men arrive at Nunivak Island in central Alaska. Mountain man Marty Raney and his son Matt search for fish but after three days and no luck the team is going hungry. With Marty seriously ill, it's up to his son to turn their luck around.
The survivalists are confronted with one of their biggest obstacles yet: the Nizina River. River crossing opportunities are hard to come by, and the rushing, unforgiving glacial waters could sweep even the toughest explorer off his feet.
With only a few days left in the expedition, the survivalists travel to Admiralty Island, home to one of the densest brown bear populations in North America. The men arrive at prime feeding time.
On the final leg of their journey, the explorers summit a massive mountain of rock and ice in the Juneau Icefield. As a final farewell gift, Alaska throws a punishing winter storm their way.
The Endurance team has a leg up as the squads race 30 miles across a menacing glacier, plunge down a 2,000-foot gully and battle 15 miles of whitewater rapids to the extraction point in Berners Bay.
And the teams are off to Chichagof Island, home to more brown bears per square mile than any other place on earth, but while the Endurance team heads for higher ground, the Moutaineers head right for trouble when their boat capsizes in rough waters.
Mission: Bushwhack through 45mi. of dense forest at Tongass National Forest, plunge down 70' waterfalls and battle the violent waters at Steven's Passage. Eager to lead, the Endurance team takes a shortcut, quickly learning that it comes at a cost.