Mount Rushmore community. Recent pine beetle infestations have threatened the forest. Mount Rushmore is largely composed of granite. The memorial is carved on the northwest margin of the Black Elk Peak granite batholith in the Black Hills of South Dakota, so the geologic formations of the heart of the Black Hills region are also evident at Mount Rushmore. The batholith magma intruded into the pre-existing mica schist rocks during the Proterozoic, 1.6 billion years ago. Coarse grained pegmatite dikes are associated with the granite intrusion of Black Elk Peak and are visibly lighter in color, thus explaining the light-colored streaks on the
Mount Rushmore in popular culture secret base inside Mount Rushmore. In "", it is the secret base of operations for the protagonists. In the film, the base, along with the sculptures on the surface, are severely damaged in a suicide bombing by Michael Moore. In the universe of the "Ben 10" franchise, Mount Rushmore is the location of the main Plumbers (a sort of intergalactic police force) complex, and plays a key role in multiple episodes of the series, including "Secrets," "Truth", the "Ben 10,000" episodes, and "Ben 10 vs. The Negative 10." The monument is inadvertently destroyed by Upchuck in the latter episode, during