Dome

View from the south, looking north at the profile of Washington protruding from natural cliffs; Between October 4, 1927, and October 31, 1941, Gutzon Borglum and 400 workers sculpted the colossal 60 foot (18 m) high carvings of U.S. presidents George Washington, Thomas Jefferson, Theodore Roosevelt, and Abraham Lincoln to represent the first 130 years of American history. These presidents were selected by Borglum because of their role in preserving the Republic and expanding its territory. The carving of Mount Rushmore involved the use of dynamite, followed by the process of "honeycombing". In total, about 450,000 short tons (408,233 t) of rock were blasted off the mountainside. In 1933, the National Park Service took Mount Rushmore under its jurisdiction. Ten years of redevelopment work culminated with the completion of extensive visitor facilities and sidewalks in 1998. It is visited by nearly 3 million people a year. Source: Wikipedia; http://en.wikipedia.org/wiki/Main_Page (accessed 3/15/2015)