The IRON HILL Challenge is a part of the Mid-Atlantic Super Series. Offering cross-country and endurance classes on a classic East Coast MTB course
Register for the Iron Hill Challenge on Bike Reg ( details here ...)
details here ...) Check out the series details. Info from their website....the M.A.S.S. has all the traditional types of races you would expect from a premier series such as cross-country races, 4 to 6 hour endurance races and 50 mile marathons the M.A.S.S. also has things you would not expect in a series such as a team relay competition, a 12 hour race and a night race.