The race from Kalkaska to Traverse City kicks off every year and continues to deliver the best experience one can find in the states (in my opinion, which is based on . . . well . . . nothing)
My explanation of Iceman is the largest mountain bike race in North America, where your time will be held against (or for) you during the entire next year.
2013 Battle at the Burg Mountain Bike Race at Cannonsburg Ski Area.