And he is saying my lands are where my dead lie buried. And he is pointing to the Black Hills. The mountain is made of solid rock. There is always a concern that there will be fault lines in the mountain. So they continually do seismic testing trying to project ahead to see if there is any weak rock and then planning to work around it when they get to it.
People are always worried about the arm and the hole under the arm.
The project is being built with conventional construction equipment. One of the first problems they ran into was the measuring device, which is mounted on the top of Crazy Horse s head. This was used to do all the measuring on the face. But it couldn t be built large enough to do the entire carving so they developed traditional construction layout procedures basically using coordinate geometry. Doing all the calculations on modern computers with modern survey instruments.