filled with all these secrets that very few people go to or set eyes on," Fedarko says. "It's a secret in plain sight."

McBride, filming the adventure, caught Fedarko referring to the experience as an ongoing river of pain, a stern epithet for a canyon that so obsessed him that it compelled him to quit his job as an editor at Outside Magazine and leave Santa Fe to work as an apprentice raft guide, rowing a boat carrying human refuse through some of the Colorado River's fiercest rapids. The experience informed his book, The Emerald Mile: The Epic Story of the Fastest Ride in History Through the Grand Canyon.

Fedarko, it seems, likes to suffer for a good story. He's writing up this latest trek for a book as well,while McBride works on a feature-length film. Both are striving to tell the story of the Grand Canyon in a way that makes the case for protecting it; despite benefitting from some of the country's strongest conservation laws, preserving the Grand Canyon makes for a daily fight. Fedarko takes that campaign to the KiMo Theater (7 pm Thursday Sept. 21. Free. 423 Central Ave. NW, Albuquerque, 505-768-3522), a teaser to a 2018 National Geographic lecture tour.

The Grand Canyon, Fedarko says, "is a place that's viewed by many if not most people to be kind of sacrosanct and permanently protected, and yet is beset by a whole range of development threats from literally every cardinal point."

On the east, a developer has proposed a tramway to the confluence of the