Marty sizes up the Alatna River to see if the current is too cold and strong.
(02:59)One group of explorers comes downhill only to find their journey just got tougher.
(01:14)These guys do it tough in the remote wilderness of Alaska.
Dangerous ice, snow and freezing conditions test these guys survival limits.
Smart, factual entertainment featuring popular science, technology, natural history, archaeology, natural mysteries.
A unique insight into the natural world, the environment and the amazing creatures that inhabit it.
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