About the same number of people have continuously thru-hiked the Grand Canyon as have walked on the moon.
A few dozen more have hiked it in sections. Two of them — author Kevin Fedarko and photographer/filmmaker Pete McBride — are here to tell their tales of trail-less miles through the heart of the Grand Canyon and the threats to the canyon they discovered along the way.
Join them in Portland on Feb 19: http://www.portland5.com/newmark-theatre/events/national-geographic-live-between-river-and-rim-hiking-grand-canyon