This is a book written by one of the Barkley "Sickos" "Frozen" Ed Furtaw on the history of the Barkley Marathons. It describes in great detail the past runnings of the race (he has run most and attended some more).
The Barkley Marathons in case you don't know is arguably the toughest race there is. It is 100 miles long (though most others measures of the course clock it at about 130 miles), it's 5 loops around some trails in the Frozen Head National Park in Tennessee. The climbing involved is around 18000m, or twice Everest or twice UTMB. The trail is often overgrown with briars (I think that is American for thorns) and there is no support in the race apart from water left at two points along a loop and the camp ground at the end of each loop. In about 20 runnings of the event 10 people have finished the 100 mile race, the course record is 55 hours. The cut off is 60 hours. Every year someone finishes the race director Laz alters the course to make it harder since this is not a race of man vs man but of man vs that. 
The accounts of his own attempts (I won't spoil it by saying how he did) along with the tales from Out There are really gripping and actually quite terrifying. Two things struck me about the race from reading the book, moreso than before.
1 - This race is a war. Or rather it's an arms race. You have probably read lots of stories about a man who gets beaten by a race and then vows to come back fitter and stronger in order to beat the race the next time. There are loads of stories like that right? Here it's just the same, except that when the race gets beaten by a man IT then comes back next time harder and stronger in order to defeat those who beat it the last time. It does not stay the same, does not get complacent, it changes and improves to win, and for this race to win it means all runners losing. I have never been part of an event like that before.
2 - Having read 100s of reasons why people drop out the reasons are very different to what I was expecting. There are a few tales of people getting lost, a few getting timed out buy the cut-offs, hardly any of injuries and not too many of complete exhaustion. The main reason people do not finish this race is that they just give up. After each loop you will be at a cosy campsite. You don't have to go back out there. Many chose not to. Then during the whole loop you are always fairly close to the "quitters road", an easy stretch of road going right back to the start. More than any other race I have ever heard of this one really breaks peoples minds.
Really really good read and recommended for anyone wanting to know more about the Barkley. The Barkley gets treated as "not a proper race" by many ultra runners today whereas reading this you may change your mind. You may even think that this is the only race there is, one where the course has a chance of winning too...
