The men are divided into two groups, building competing rafts. Mountain man Marty Raney is taking charge, building a colossal raft weighing nearly 2 tons which he hopes will be sturdy enough in the rapids. After spending five hours on construction, the five-man crew get on their way, but hunger starts to take its toll. Dallas Seavey, his brother Tyrell and survival expert Austin Manelick are meticulously engineering a smaller raft that’s speedy and maneuverable to tackle the turbulent Yukon.