The Run Amuck Challenge is filled with steep hills, obstacle courses and deep mud pits — but none of that stopped a blind man from participating. Charlie Plaskon, 69, of Long Island, N.Y. , completed the course held Saturday at Marine Corps Base Quantico, Va. He did so with the aid of a Marine, Master Sgt. Donald Ogden. Plaskon, a marathon-running grandfather, was one of more than 2,500 participants who trekked through three and a half miles of muddy trails and pits. Ogden’s office at Marine Corps Recruiting Command received a request from public affairs to lead a blind runner through…