Mount Rushmore the headquarters for their film "". "" also depicts this location as a secret cover for a fictional gold city. The memorial was also famously used as the location of the climactic chase scene in Alfred Hitchcock's 1959 movie "North by Northwest". Deep Purple's breakthrough album, 1970's "In Rock", parodies the sculpture. On August 11, 1952, the U.S. Post Office issued the Mount Rushmore Memorial commemorative stamp on the 25th anniversary of the dedication of the Mt. Rushmore National Memorial in the Black Hills of South Dakota. On January 2, 1974, a depicting the monument was also issued. Notes Further
Mount Rushmore of Mount Rushmore", posing for photographs with thousands of tourists. He became one of the most photographed people in the world. The ongoing conservation of the site is overseen by the 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. The components of Borglum's sealant included linseed oil, granite dust, and white lead, but a modern silicone replacement is now used, disguised with granite dust. In 1998, electronic monitoring devices were installed to track movement in the topology of the sculpture