Marching On Together

Any of our American posters heard of this event, there's a film about it called "Just one mile" basically a route consisting of 1.1 mile in central Pennsylvania, goes on till only one runner is left, Chad Wright is holder with after running for 38 hours and covering 122.1 miles with 37,740 feet of elevation.
Some feat of endurance that.
Wonder what distance mountain runs !!