This story is free to read.

Race that eats its young: Barkley Marathons may be world’s toughest trail run

Staff Photo by Dan Henry / The Chattanooga Times Free Press- 4/3/16. Dale Holdaway, originally from Michigan currently living in Brazil, makes his way up the Chimney Top Trail on his third loop during the 30th running of the Barkley Marathons at Frozen Head State Park in Warburg, Tenn., on April 3, 2016. This was Holdaway's fifth attempt and he missed the 40-hour "Fun Run" (3-lap) cutoff by a few hours upon completing his third lap. The Barkley Marathons is in its 30th year and consists of part orienteering and part ultra marathon where a select few attempt to complete five 20 mile loops within a 60-hour time limit where they search for hidden book caches deep in the woods throughout the park. Staff Photo by Dan Henry / The Chattanooga Times Free Press- 4/3/16. Dale Holdaway, originally from Michigan currently living in Brazil, makes his way up the Chimney Top Trail on his third loop during the 30th running of the Barkley Marathons at Frozen Head State Park in Warburg, Tenn., on April 3, 2016. This was Holdaway's fifth attempt and he missed the 40-hour "Fun Run" (3-lap) cutoff by a few hours upon completing his third lap. The Barkley Marathons is in its 30th year and consists of part orienteering and part ultra marathon where a select few attempt to complete five 20 mile loops within a 60-hour time limit where they search for hidden book caches deep in the woods throughout the park.

By David Cobb April 6, 2016 14 min read

Photo Gallery

The Barkley Marathons: The race that eats its young

Staff Photo by Dan Henry / The Chattanooga Times Free Press- 4/4/16. Gary Robbins descends "Rat Jaw" from the Frozen Head Lookout Tower on his fifth loop where a water drop and braille book awaited during the 30th running of the Barkley Marathons at Frozen Head State Park in Warburg, Tenn., on April 4, 2016. Robbins completed four and a half loops before pulling himself from the race due hallucinations from lack of sleep. The Barkley Marathons is part orienteering, part ultra marathon where a select few attempt to complete up to five 20 mile loops within a 60-hour time limit where they search for hidden book caches deep in the woods throughout the park.

Staff Photo by Dan Henry / The Chattanooga Times Free Press- 4/4/16. Gary Robbins rests in the shade for a moment during his fifth loop and speaks to other racers who dropped out while at the Frozen Head Lookout Tower during the 30th running of the Barkley Marathons at Frozen Head State Park in Warburg, Tenn., on April 4, 2016. Robbins completed four and a half loops before pulling himself from the race due hallucinations from lack of sleep. The Barkley Marathons is part orienteering, part ultra marathon where a select few attempt to complete up to five 20 mile loops within a 60-hour time limit where they search for hidden book caches deep in the woods throughout the park.

Staff Photo by Dan Henry / The Chattanooga Times Free Press- 4/4/16. Gary Robbins picks up a braille page before departing from the Frozen Head Lookout Tower on his fifth loop during the 30th running of the Barkley Marathons at Frozen Head State Park in Warburg, Tenn., on April 4, 2016. Robbins completed four and a half loops before pulling himself from the race due hallucinations from lack of sleep. The Barkley Marathons is part orienteering, part ultra marathon where a select few attempt to complete up to five 20 mile loops within a 60-hour time limit where they search for hidden book caches deep in the woods throughout the park.

Staff Photo by Dan Henry / The Chattanooga Times Free Press- 4/4/16. Gary Robbins rests in the shade for a moment before departing from the Frozen Head Lookout Tower on his fifth loop during the 30th running of the Barkley Marathons at Frozen Head State Park in Warburg, Tenn., on April 4, 2016. Robbins completed four and a half loops before pulling himself from the race due hallucinations from lack of sleep. The Barkley Marathons is part orienteering, part ultra marathon where a select few attempt to complete up to five 20 mile loops within a 60-hour time limit where they search for hidden book caches deep in the woods throughout the park.

Staff Photo by Dan Henry / The Chattanooga Times Free Press- 4/4/16. Gary Robbins makes his way up "Rat Jaw" to the Frozen Head Lookout Tower on his fifth loop where a water drop and braille book await during the 30th running of the Barkley Marathons at Frozen Head State Park in Warburg, Tenn., on April 4, 2016. Robbins completed four and a half loops before pulling himself from the race due hallucinations from lack of sleep. The Barkley Marathons is part orienteering, part ultra marathon where a select few attempt to complete up to five 20 mile loops within a 60-hour time limit where they search for hidden book caches deep in the woods throughout the park.

Staff Photo by Dan Henry / The Chattanooga Times Free Press- 4/4/16. Spectators watch as Gary Robbins makes his way up "Rat Jaw" to the Frozen Head Lookout Tower on his fifth loop where a water drop and braille book await during the 30th running of the Barkley Marathons at Frozen Head State Park in Warburg, Tenn., on April 4, 2016. Robbins completed four and a half loops before pulling himself from the race due hallucinations from lack of sleep. The Barkley Marathons is part orienteering, part ultra marathon where a select few attempt to complete up to five 20 mile loops within a 60-hour time limit where they search for hidden book caches deep in the woods throughout the park.

Staff Photo by Dan Henry / The Chattanooga Times Free Press- 4/4/16. The Brushy Mountain State Penitentiary was one of the book cache locations during the 30th running of the Barkley Marathons at Frozen Head State Park in Warburg, Tenn., on April 2-4, 2016. The Barkley Marathons is part orienteering, part ultra marathon where a select few attempt to complete up to five 20 mile loops within a 60-hour time limit where they search for hidden book caches deep in the woods throughout the park.

Staff Photo by Dan Henry / The Chattanooga Times Free Press- 4/4/16. Gary "Laz" Cantrell stands in the sunlight while waiting for racers to return during the 30th running of the Barkley Marathons at Frozen Head State Park in Warburg, Tenn., on April 4, 2016. The Barkley Marathons is part orienteering, part ultra marathon where a select few attempt to complete up to five 20 mile loops within a 60-hour time limit where they search for hidden book caches deep in the woods throughout the park.

Staff Photo by Dan Henry / The Chattanooga Times Free Press- 4/4/16. Gary "Laz" Cantrell rings a bell as racers head out for their fifth lap during the 30th running of the Barkley Marathons at Frozen Head State Park in Warburg, Tenn., on April 4, 2016. The Barkley Marathons is part orienteering, part ultra marathon where a select few attempt to complete up to five 20 mile loops within a 60-hour time limit where they search for hidden book caches deep in the woods throughout the park.

Staff Photo by Dan Henry / The Chattanooga Times Free Press- 4/4/16. Jared Campbell kisses his wife Mindy Campbell before heading out on his fourth loop during the 30th running of the Barkley Marathons at Frozen Head State Park in Warburg, Tenn., on April 3, 2016. Campbell completed the race earning the designation of the first person to ever finish three times. The Barkley Marathons is part orienteering, part ultra marathon where a select few attempt to complete up to five 20 mile loops within a 60-hour time limit where they search for hidden book caches deep in the woods throughout the park.

Staff Photo by Dan Henry / The Chattanooga Times Free Press- 4/4/16. Jared Campbell's wife Mindy Campbell applies sunscreen to his arms before he heads out on his fifth loop during the 30th running of the Barkley Marathons at Frozen Head State Park in Warburg, Tenn., on April 4, 2016. Campbell completed the race earning the designation of the first person to ever finish three times. The Barkley Marathons is part orienteering, part ultra marathon where a select few attempt to complete up to five 20 mile loops within a 60-hour time limit where they search for hidden book caches deep in the woods throughout the park.

Staff Photo by Dan Henry / The Chattanooga Times Free Press- 4/4/16. Jared Campbell returns to the campsite from his fourth loop during the 30th running of the Barkley Marathons at Frozen Head State Park in Warburg, Tenn., on April 4, 2016. Campbell completed the race earning the designation of the first person to ever finish three times. The Barkley Marathons is part orienteering, part ultra marathon where a select few attempt to complete up to five 20 mile loops within a 60-hour time limit where they search for hidden book caches deep in the woods throughout the park.

Staff Photo by Dan Henry / The Chattanooga Times Free Press- 4/4/16. Jared Campbell returns to the campsite from his third loop during the 30th running of the Barkley Marathons at Frozen Head State Park in Warburg, Tenn., on April 3, 2016. Campbell completed the race earning the designation of the first person to ever finish three times. The Barkley Marathons is part orienteering, part ultra marathon where a select few attempt to complete up to five 20 mile loops within a 60-hour time limit where they search for hidden book caches deep in the woods throughout the park.

Staff Photo by Dan Henry / The Chattanooga Times Free Press- 4/4/16. Jared Campbell, left, and Gary Robbins prepare to head out for their fourth loop during the 30th running of the Barkley Marathons at Frozen Head State Park in Warburg, Tenn., on April 4, 2016. Campbell completed the race earning the designation of the first person to ever finish three times and Robbins completed four and a half loops before pulling himself from the race due hallucinations from lack of sleep. The Barkley Marathons is part orienteering, part ultra marathon where a select few attempt to complete up to five 20 mile loops within a 60-hour time limit where they search for hidden book caches deep in the woods throughout the park.

Staff Photo by Dan Henry / The Chattanooga Times Free Press- 4/4/16. Gary Robbins, left, and Jared Campbell return from their third loop during the 30th running of the Barkley Marathons at Frozen Head State Park in Warburg, Tenn., on April 3, 2016. Campbell completed the race earning the designation of the first person to ever finish three times and Robbins completed four and a half loops before pulling himself from the race due hallucinations from lack of sleep. The Barkley Marathons is part orienteering, part ultra marathon where a select few attempt to complete up to five 20 mile loops within a 60-hour time limit where they search for hidden book caches deep in the woods throughout the park.

Staff Photo by Dan Henry / The Chattanooga Times Free Press- 4/4/16. Gary Robbins receives his race number from Gary ԌazՠCantrell before heading out on his fifth loop during the 30th running of the Barkley Marathons at Frozen Head State Park in Warburg, Tenn., on April 4, 2016. Robbins completed four and a half loops before pulling himself from the race due hallucinations from lack of sleep. The Barkley Marathons is part orienteering, part ultra marathon where a select few attempt to complete up to five 20 mile loops within a 60-hour time limit where they search for hidden book caches deep in the woods throughout the park.

Staff Photo by Dan Henry / The Chattanooga Times Free Press- 4/4/16. Gary Robbins gears up before heading out on his fifth loop during the 30th running of the Barkley Marathons at Frozen Head State Park in Warburg, Tenn., on April 4, 2016. Robbins completed four and a half loops before pulling himself from the race due hallucinations from lack of sleep. The Barkley Marathons is part orienteering, part ultra marathon where a select few attempt to complete up to five 20 mile loops within a 60-hour time limit where they search for hidden book caches deep in the woods throughout the park.

Staff Photo by Dan Henry / The Chattanooga Times Free Press- 4/4/16. Gary Robbins tosses his son Reed in the air before heading out on his fifth loop during the 30th running of the Barkley Marathons at Frozen Head State Park in Warburg, Tenn., on April 4, 2016. Robbins completed four and a half loops before pulling himself from the race due hallucinations from lack of sleep. The Barkley Marathons is part orienteering, part ultra marathon where a select few attempt to complete up to five 20 mile loops within a 60-hour time limit where they search for hidden book caches deep in the woods throughout the park.

Staff Photo by Dan Henry / The Chattanooga Times Free Press- 4/4/16. Gary Robbins tosses his son Reed in the air before heading out on his fourth loop during the 30th running of the Barkley Marathons at Frozen Head State Park in Warburg, Tenn., on April 3, 2016. Robbins completed four and a half loops before pulling himself from the race due hallucinations from lack of sleep. The Barkley Marathons is part orienteering, part ultra marathon where a select few attempt to complete up to five 20 mile loops within a 60-hour time limit where they search for hidden book caches deep in the woods throughout the park.

Staff Photo by Dan Henry / The Chattanooga Times Free Press- 4/3/16. Gary Robbins winces in pain as he swaps out socks before heading out on his fifth loop during the 30th running of the Barkley Marathons at Frozen Head State Park in Warburg, Tenn., on April 3, 2016. Robbins completed four and a half loops before pulling himself from the race due hallucinations from lack of sleep. The Barkley Marathons is part orienteering, part ultra marathon where a select few attempt to complete up to five 20 mile loops within a 60-hour time limit where they search for hidden book caches deep in the woods throughout the park.

Staff Photo by Dan Henry / The Chattanooga Times Free Press- 4/3/16. "Danger" Dave Henn plays taps on the bugle as Iso Yucra pulls himself from the race during the 30th running of the Barkley Marathons at Frozen Head State Park in Warburg, Tenn., on April 2-4, 2016. The Barkley Marathons is part orienteering, part ultra marathon where a select few attempt to complete up to five 20 mile loops within a 60-hour time limit where they search for hidden book caches deep in the woods throughout the park.

Staff Photo by Dan Henry / The Chattanooga Times Free Press- 4/3/16. John Kelly makes his way out of the Frozen Head State Park campground to start his fourth loop during the 30th running of the Barkley Marathons at Frozen Head State Park in Warburg, Tenn., on April 3, 2016. Kelly completed four loops and began a fifth before deciding to quit. The Barkley Marathons is part orienteering, part ultra marathon where a select few attempt to complete up to five 20 mile loops within a 60-hour time limit where they search for hidden book caches deep in the woods throughout the park.

Staff Photo by Dan Henry / The Chattanooga Times Free Press- 4/3/16. John Kelly makes his way into the Frozen Head State Park campground with compass abrasions on his neck upon finishing his third loop during the 30th running of the Barkley Marathons at Frozen Head State Park in Warburg, Tenn., on April 3, 2016. Kelly completed four loops and began a fifth before deciding to quit. The Barkley Marathons is part orienteering, part ultra marathon where a select few attempt to complete up to five 20 mile loops within a 60-hour time limit where they search for hidden book caches deep in the woods throughout the park.

Staff Photo by Dan Henry / The Chattanooga Times Free Press- 4/3/16. John Kelly makes his way into the Frozen Head State Park campground upon finishing his third loop during the 30th running of the Barkley Marathons at Frozen Head State Park in Warburg, Tenn., on April 3, 2016. Kelly completed four loops and began a fifth before deciding to quit. The Barkley Marathons is part orienteering, part ultra marathon where a select few attempt to complete up to five 20 mile loops within a 60-hour time limit where they search for hidden book caches deep in the woods throughout the park.

Staff Photo by Dan Henry / The Chattanooga Times Free Press- 4/3/16. Racers Brad Compton, Kimberly Durst and Starchy Grant enter the Frozen Head State Park campground to finish a single 20-mile loop in 31hours 59minutes setting the record for the most time spent on one loop in race history. The Barkley Marathons is part orienteering, part ultra marathon where a select few attempt to complete up to five 20 mile loops within a 60-hour time limit where they search for hidden book caches deep in the woods throughout the park.

Staff Photo by Dan Henry / The Chattanooga Times Free Press- 4/3/16. Kimberly Durst becomes emotional as she completes a single 20-mile loop in 31hours 59minutes setting the record for the most time spent on one loop in race history. The Barkley Marathons is part orienteering, part ultra marathon where a select few attempt to complete up to five 20 mile loops within a 60-hour time limit where they search for hidden book caches deep in the woods throughout the park.

Staff Photo by Dan Henry / The Chattanooga Times Free Press- 4/3/16. "Frozen" Ed Furtaw speaks to racers during the 30th running of the Barkley Marathons at Frozen Head State Park in Warburg, Tenn., on April 2-4, 2016. The Barkley Marathons is part orienteering, part ultra marathon where a select few attempt to complete up to five 20 mile loops within a 60-hour time limit where they search for hidden book caches deep in the woods throughout the park.

Staff Photo by Dan Henry / The Chattanooga Times Free Press- 4/3/16. Jennilyn Eaton from Salt Lake City makes her way up the Chimney Top Trail on her third loop during the 30th running of the Barkley Marathons at Frozen Head State Park in Warburg, Tenn., on April 3, 2016. Jennilyn was the only female to start a third loop at the 2016 Barkley. The Barkley Marathons is in its 30th year and consists of part orienteering and part ultra marathon where a select few attempt to complete five 20 mile loops within a 60-hour time limit where they search for hidden book caches deep in the woods throughout the park.

Staff Photo by Dan Henry / The Chattanooga Times Free Press- 4/3/16. Jennilyn Eaton from Salt Lake City makes her way down the Chimney Top Trail on her second loop during the 30th running of the Barkley Marathons at Frozen Head State Park in Warburg, Tenn., on April 3, 2016. Jennilyn was the only female to start a third loop at the 2016 Barkley. The Barkley Marathons is in its 30th year and consists of part orienteering and part ultra marathon where a select few attempt to complete five 20 mile loops within a 60-hour time limit where they search for hidden book caches deep in the woods throughout the park.

Staff Photo by Dan Henry / The Chattanooga Times Free Press- 4/3/16. Spectators congregate in at the race staging area to wait for participants to arrive during the 30th running of the Barkley Marathons at Frozen Head State Park in Warburg, Tenn., on April 3, 2016. The Barkley Marathons is part orienteering, part ultra marathon where a select few attempt to complete up to five 20 mile loops within a 60-hour time limit where they search for hidden book caches deep in the woods throughout the park.

Staff Photo by Dan Henry / The Chattanooga Times Free Press- 4/4/16. License plates brought by participants line the race staging area during the 30th running of the Barkley Marathons at Frozen Head State Park in Warburg, Tenn., on April 3, 2016. The Barkley Marathons is part orienteering, part ultra marathon where a select few attempt to complete up to five 20 mile loops within a 60-hour time limit while searching for hidden book caches deep in the woods throughout the park.

Staff Photo by Dan Henry / The Chattanooga Times Free Press- 4/4/16. Spectators congregate at the race staging area to wait for participants to arrive during the 30th running of the Barkley Marathons at Frozen Head State Park in Warburg, Tenn., on April 3, 2016. The Barkley Marathons is part orienteering, part ultra marathon where a select few attempt to complete up to five 20 mile loops within a 60-hour time limit while searching for hidden book caches deep in the woods throughout the park.

Deep in the rugged mountains of rural East Tennessee, a foot race is pushing the limits of human capability.

At close to 130 miles and with 65,000 feet of climbing, some say it’s the world’s toughest trail race. But it measures more than just speed and endurance.

And most have never heard of it.

For decades, the race has lived below the radar of general public awareness, its location and date known only to its inner circle and a group of devoted fans who anxiously await its arrival each spring.

But on a recent Friday morning, dozens of cameramen and spectators descended on a small state park near the old Brushy Mountain State Penitentiary to witness the spectacle that is the Barkley Marathons.