The North Face Endurance Challenge series offers a range of race distance for all levels of runners: 10K, half marathon, marathon, 50K and 50 miles. Events were held in five locations across the U.S. in 2013, including the culminating event in the Marin Headlands north of San Francisco on Dec. 7-8. The 50-mile championship race offers the biggest prize purse in trail running, with $10,000 checks going to the male and female winner. Since it’s inception in 2006, the race attracted some of the world’s best trail runners and this year was no exception. Rob Krar from Flagstaff, Ariz., and Michele Yates of Littleton, Colo., each turned in dominant performances to claim this year’s championship titles. This photo gallery shows the race in pictures and some of the stunning scenery that the 600-plus runners experienced. In all, the five races drew about 2,500 runners. For results, go to this link.