As wondrous as the National Park System is, it holds wild and rugged settings that, frankly, can kill you if you're not prepared. That point is clearly driven home in The Kolob Tragedy: The Lost Tale Of A Canyoneering Calamity, which recounts the missteps of a fatal trip through the backcountry of Zion National Park in Utah.

Relying on official reports, court records, interviews, and his own trek down Kolob Creek, Noel de Nevers fashions a nearly first-person account of a July 1993 canyoneering trek that resulted in the deaths of two adults and the rescue five days later of another adult and five teenagers under his charge deep in a slot canyon in the northern end of the park.

The author makes no attempt to sensationalize the events. Indeed, the account he knits together from his investigation is riveting enough to hold your attention and, hopefully, raise the awareness of park visitors who might overestimate their ability to explore the backcountry of Zion, or any other national park, for that matter.

The story is straightforward: A youth group from the Church of Latter-Day Saints in Salt Lake City planned a four-day canyoneering trek through Zion. What quickly becomes evident is that the group's leader, 27-year-old David Fleischer, underestimated the conditions in Kolob Creek as well as his own ability and the abilities of those under his charge.

Kolob Creek offers a steep, narrow, and highly popular multi-day hike through one of Zion's serpentine slot canyons. From the northern end of the park it winds about 14 miles to The Narrows of the Virgin River, with hikers exiting at the Tempe of Sinawava in Zion Canyon not far from the park lodge. There actually are two entry routes to the hike -- the less technical MIA, or Mutual Improvement Association route, named for an LDS summer camp, and the decidedly more rigorous Rappel Route that requires multiple rappels, some of more than 100 feet. 

Fleischer had done the Rappel Route once before, and picked it for his group's adventure. What he didn't realize, but which became immediately evident, was that water running through the canyon was flowing at a much higher, and highly dangerous, flow than when he had first traveled the route with a friend two years earlier. Instead of trickling flows along the creek floor that Fleischer encountered on his first trip, now there were gushing waterfalls with dangerous undertows.

By the end of the second day two of the three adults, Fleischer and Kim Ellis, were dead, having drowned in whirlpooling torrents of water created by upstream releases from an out-of-park reservoir. 

The author, a retired chemical engineering professor from the University of Utah who relished the outdoors and became an avid canyoneering participant and for a while was on the "expert list" submitted for this case's trial, takes an analytical approach to the story. He explains the sport of canyoneering, the required equipment and necessary skills, and pieces together the youth group's story, the National Park Service search-and-rescue mission that resulted, and the run-up to a wrongful death trial that ended with a $2.24 million out-of-court settlement shortly before the trial was to begin in 1996.

Less than 150 pages, this book is a quick, illuminating, and gripping read that also touches on the public policy issues that the Park Service grapples with in letting visitors into backcountry areas that can be dangerous. In the wake of the tragedy, the park received numerous calls from other backcountry travelers.

"Most people are saying, 'Please don't make it so sanitary that there are no risks,'" (Denny) Davies, (spokesman for Zion National Park) said of the calls pouring into Zion. "We want to engage wild America on its own terms. And we don't desire your protection."

The Kolob Tragedy is a must-read for anyone considering a canyoneering trek, whether in Zion National Park or anywhere else.