Video: Thru Hiking the Grand Canyon - Thirst and Threats in the Godscape (Part 3)

Today we have the third – and final – video in the National Geographic series that follows photographer Pete McBride and journalist Kevin Fedarko on 650 mile (1046 km) thru-hike of the Grand Canyon, as they explore the threats that that place now faces. They've discovered that amongst those threats are environmental issues, climate change, encroaching commercial interests, and more. As their journey nears and end, the two men face a challenge of their own – potentially running out of water in a remote corner of the national park. Find out how their expedition wraps up in this installment of the series.