The Barkley Marathons is an ultramarathon trail race held in Tennessee in late March or early April of each year. The full course is five x 20 mile loops though woods and hills which often has thick undergrowth and few trails. There is one map at the start line for runners to copy, and no GPS technology or course markings are available for runners.
If runners complete 60 miles, this is known as a "fun run." The full course is about 100 miles and attracts about 40 participants every year. The full race is limited to a 60-hour cut-off while the “Fun Run” is three laps within 40 hours.
The total elevation gain for the five loops is in the region of 60,000 feet (~11kms) which is the equivalent of climbing Mount Everest twice.
Only 15 individuals have finished the full 5 loop course in under 60 hours.
Barkley Finishers: Mark Williams (1995), David Horton (2001), Blake Wood (2001), Ted Kaiser (2003), Mike Tilden (2004), Jim Nelson (2004), Brian Robinson (2008), Andrew Thompson (2009), Jonathan Basham (2010), Brett Maune (2011, 2012), John Fegyveresi (2012), Jared Campbell (2012, 2014, 2016), Nick Hollon (2013), Travis Wildeboer (2013), John Kelly (2017)
As the list shows, no-one has completed the course since 2017!
This video gives a taste of what must be one of the worlds toughest races.