The original plan of Borglum's was to carve into the Needles range of the mountain but upon further inspection they found that area couldn't handle sculpting.
It was either find a new place or forget about doing the project. This is when they looked at sculpting Mount Rushmore.
When Borglum say Mount Rushmore he knew it was a perfect spot as it got sun most the day, it was the highest peak around and is made of granite that erodes only one inch every 10,000 years.
Next they had to decide on who to carve and choose the four presidents Washington, Jefferson, Roosevelt and Lincoln.
Above is an example of this type of rock which Mount Rushmore is carved out of?
| Granite | Marble | Basalt |