The Grand Canyon has attracted countless characters to its depths, many as famed as its rapids, since it was first run by the one-armed explorer John Wesley Powell in 1869. Among the most legendary, however, is the late, great whitewater pioneer and fiery conservationist Martin Litton who founded Grand Canyon Dories and played a pivotal role in defeating two proposed dams in 1950s that would have flooded much of the classic run. Sierra Club president David Brower once called Litton–who inspired the club to take aggressive action against the dams–his “conscience.”

Despite winning those battles, the Grand Canyon was still facing a number of threats when Litton passed away in 2014 at the age of 97. A tram has been proposed at the confluence of the Little Colorado and Colorado rivers that would carry up to 10,000 people per day to the canyon floor. On the rim, development interests want to tap aquifers that could dry up some of the canyon’s most iconic springs. And uranium mining continues to threaten the greater Grand Canyon region.

A new film by National Geographic photographer and award-winning filmmaker Pete McBride picks up the story of Martin Litton and the battle to preserve the Grand Canyon by following a new dory built in Litton’s honor on a two-week trip down the canyon. Check out the trailer to Martin’s Boat above and learn more about the project here:

–Martin Litton was the recipient of Canoe & Kayak‘s Lifetime Achievement Award in 2012. Watch his acceptance speech.

C&K Heroes: Martin Litton