This loop is fun in either direction. I love climbing Viper, and the tight turns of the trail make it feel longer than it is. Anaconda somehow manages to feel downhill in both directions, and Iron Brigade is a fast start or finish. Feeder line, the short loop near the SE Maple Ridge Dr exit/entry point, is more popular with bikers than hikers and runners due to its steep climbs and bermed turns. Watch out for downed trees after rain or a storm.