As I have blogged about previously, 90% of Mount Rushmore was carved with dynamite. Twice a day, at noon and at 4:00 p.m. the crew would come down from the mountain and the dynamite would be ignited. Tons of granite ended up at the bottom of the mountain.
This a photo I took of Mount Rushmore looking up from the bottom of the rubble pile.
A fact not in the book: Originally, Gutzon had planned to remove all the debris but in the end Lincoln had run out of money so the rubble pile stayed. Now, it is hard to imagine the Presidents without it.