In 2016 filmmaker/photographer Pete McBride and writer Kevin Fedarko set out on a 750-mile journey on foot through the entire length of the Grand Canyon. More people have stood on the moon than have accomplished this task. Their quest was more than just an endurance test — it was also a way to draw attention to the unprecedented threats facing one of our most revered landscapes. Throughout their passage, McBride and Fedarko encountered an astonishingly diverse and powerful landscape, rich in history, which is now facing perhaps the gravest crisis in the 100-year history of the Grand Canyon National Park. This film tells the story of extreme physical hardship that stretches the bonds of friendship and meditates on the timeless beauty of this sacred place.