A Walk in the Park by Kevin Fedarko is an excellent work of nonfiction subtitled The True Story of a Spectacular Misadventure in the Grand Canyon. It's fascinating reading about a beautiful area, one that Fedarko was introduced to when he at eleven years old was given by his father a book The Man Who Walked Through Time by Colin Fletcher about his 1963 Grand Canyon hike.
In 2015, Fedarko and his friend and colleague Pete McBride set out on an end-to-end traverse of the Grand Canyon. There's not a trail for the trip and at the time, only ten people had done a thru-hike of the canyon, and only another roughly dozen had done the complete hike in pieces, what Fedarko and McBride intended. The trip begins at Lee's Ferry and ends at the Grand Wash Cliffs to the west and Fedarko and McBride started in the company of high-qualified Rich Rudow and three other accomplished hikers. Rudow and his three fellow travelers had a planned 57-day itinerary, spanning some 700 miles, with a route was often well above the river, and below the top of the canyon, traveling among the various rock strata or layers in the canyon. The idea was that Fedarko and McBride would complete a section over twelve days, the others would continue on, and then the two would return later to do additional sections.
Fedarko and McBride didn't know what they were doing and set out with packs twenty pounds heavier than the experienced hikers, with weight a critically important variable in backpacking. The group had to tunnel through hedges and hop across boulder fields. McBride at one point was beset by a dangerous heat-related imbalance of sodium in his bloodstream, one that caused him to suffer a series of muscle cramps, making his abdomen look as if something moving through it. The two cut their trip short, quitting the section roughly halfway through. Their plans then rebooted after Rich reached out to friends and asked if they would help the pair compete their hike, properly prepared this time. It was interesting reading of how Fedarko, McBride, and their new companions (joined by Rich) would hike with the Colorado River far below, containing rafters guiding through the canyon, floating with the occasional stop to hike a short trail.
Also in the book is the history of the tribes in the canyon, and development efforts, such as an intended cable-driven tramway from the top of the canyon to the river, effectively ruining the tribes ancestral lands, and helicopter alley towards the end of the canyon. It's a great travelogue story and an interesting read.