The Roaring Fork Valley is full of highly competitive, endurance athletes and they have long enjoyed the Power of Four races in the winter. Earlier this month there was a Power of Four mountain run, and on August 1, the Audi Power of Four race series moves to mountain biking, with the Power of 4 Mountain Bike Race. The race is a 33-mile point to point event combining single and double-track trails across the diverse terrain of all four ski mountains and nearly 9,000 vertical feet gain/loss. This year, a shorter 17-mile course, the Power of 2, will be offered to participants as well, utilizing trails across Snowmass and Buttermilk. Details at www.aspensnowmass.com.