This must have happened before the blizzard that paralyzed that part of South Dakota over the last few days. Right now no one can even get to Mount Rushmore.
As I understand it the cones were put up before 10/1, state officials asked they be taken down which they were but were then put back. 3 days later the blizzard + snow plows came along and took control, for the time being. Winter can’t get here soon enough.