The making of Mount Rushmore was not an easy task and so is the maintenance of the same. A lot of effort is required to maintain this place the way it was made in first place. The color and shape of the monument is needed to be in tact. Maintenance staff is appointed to take care of the monument as well as the part where tourists walk. As this monument is made out of a granite Rock, there is a possibility that it will starts to crack and rupture on its own with time. Prevent it from damaging, National park service and the Mount Rushmore society started doing research in order to study the structural integrity of the monument so that they can come across the weak points of the same.
While doing the research, they found out the cracks which were intentionally created by Borglum. They were made up of linseed oil, white lead and granite dust. Researchers realized that these cracks were made to keep the structures safe from moisture and water which will lead in in safety of the monument.