Are you looking for a challenge this Fall? How do you feel about running 6 marathons in 3 states over 6 days? No big deal, just your regular routine, right? In all seriousness, Mainly Marathons has an exciting race series called the Northwest Marathon Series that will give you a chance to do something epic. Or if you’d just rather do just one of the races in the series or pick and choose, that’s an option…