if you're visiting Aspen this weekend and you're an enthusiastic endurance runner, Saturday is the day for you! The Power of Four trail run will offer athletes of various levels an opportunity to do their thing, and supporters can come to cheer them on and marvel at their devotion to the sport. According to the Aspen Times, competitors can choose from three distances: a 50K (31 miles) race that starts at the base of Aspen Mountain; a 25K (15.5 miles) beginning at the base of the Tiehack lift on Buttermilk; or a 10K (6.2 miles) that starts at the top of the Elk Camp gondola in Snowmass. All of the race routes will end at the base of Fanny Hill near the Snowmass Base Village. And, for those of us who find all the options exhausting, it will be fun to celebrate with the participants at the base of Fanny Hill.