Conservation
When was the site digitally recorded?
Mount Rushmore
The ongoing conservation of the site is overseen by the US National Park Service. Physical efforts to conserve the monument have included replacement of the sealant applied originally by Gutzon Borglum, which had proved ineffective at providing water resistance (components include linseed oil, granite dust and white lead). A modern silicone replacement was used, disguised with granite dust. In 1998, electronic monitoring devices were installed to track movement in the topology of the sculpture to an accuracy of 3 mm. The site has been subsequently digitally recorded using a terrestrial laser scanning methodology in 2009 as part of the international Scottish Ten project, providing a record of unprecedented resolution and accuracy to inform the conservation of the site. This data was made accessible online to be freely used by the wider community to aid further interpretation and public access.