The annual event has been cancelled due to the growing fire danger in a forest decimated by pine beetles.
Pine beetles have killed most of the trees in the Black Elk Wilderness, which butts up against Mount Rushmore National Memorial. The memorial contains about 1,200 acres of forest.
Foresters say dead and dying trees pose a much greater risk of wildfire.
The condition of the forest is such that, unlike any other year before, there is a greater risk of a wildfire growing into a catastrophic fire, because there's more dead forest close to the park than any other previous year.