McDowell Mountain Regional Park, Phoenix, AZ. 12-hour endurance mountain bike competition. One of our most popular events, starting right before sunrise and finishing just after sunset! Take in some awesome views of the Sonoran Desert on this varietal trail while winding through technical turns and dipping into mini canyons. Course is an intermediate 16.5 mi. loop that has a 917 ft. elevation gain and 60% singletrack.