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
Virginia State Route 263 Virginia State Route 263 State Route 263 (SR 263) is a primary state highway in the U.S. state of Virginia. Known as Orkney Grade, the state highway runs from SR 659 in Orkney Springs east to U.S. Route 11 (US 11) in Mount Jackson. SR 263 connects Mount Jackson with a resort area in the mountains of southwestern Shenandoah County. SR 263 is a Virginia Byway. SR 263 begins at the eastern end of Shrine Mont Circle, a loop that is designated SR 659 and serves Shrine Mont, an Episcopal Diocese of Virginia retreat that hosts the annual Shenandoah Valley