The Mount Rushmore National Memorial is a sculpture carved into the granite face of Mount Rushmore near Keystone, South Dakota, in the United States. Sculpted by Danish-American Gutzon Borglum and his son, Lincoln Borglum, Mount Rushmore features 60-foot (18 m) sculptures of the heads of former United States presidents (in order from left to right) George Washington, Thomas Jefferson, Theodore Roosevelt and Abraham Lincoln. The entire memorial covers 1,278.45 acres (5.17 km2) and is 5,725 feet (1,745 m) above sea level. The tallest mountain in the region is Harney Peak (7,242 feet or 2,207 metres).
South Dakota historian Doane Robinson is credited with conceiving the idea of carving the likenesses of famous people into the Black Hills region of South Dakota in order to promote tourism in the region. Robinson's initial idea was to sculpt The Needles; however, Gutzon Borglum rejected the Needles site due to the poor quality of the granite and strong opposition from environmentalists and Native American groups. They settled on the Mount Rushmore location, which also has the advantage of facing southeast for maximum sun exposure. Robinson wanted it to feature western heroes like Lewis and Clark, Red Cloud and Buffalo Bill Cody but Borglum decided the sculpture should have a more national focus, and chose the four presidents whose likenesses would be carved into the mountain.
After securing federal funding, construction on the memorial began in 1927, and the presidents' faces were completed between 1934 and 1939. Upon Gutzon Borglum's death in March 1941, his son Lincoln Borglum took over construction. Although the initial concept called for each president to be depicted from head to waist, lack of funding forced construction to end in late October 1941. The U.S. National Park Service took control of the memorial in 1933, while it was still under construction, and manages the memorial to the present day. It attracts nearly three million people annually.
The flora and fauna of Mount Rushmore are similar to those of the rest of the Black Hills region of South Dakota. Birds including the Turkey vulture, bald eagle, hawk, and meadowlark fly around Mount Rushmore, occasionally making nesting spots in the ledges of the mountain. Smaller birds, including songbirds, nuthatches, and woodpeckers, inhabit the surrounding pine forests.
Terrestrial mammals include the mouse, chipmunk, squirrel, skunk, porcupine, raccoon, beaver, badger, coyote, bighorn sheep, and bobcat. In addition, several species of frogs and snakes inhabit the region. The two streams in the memorial, the Grizzly Bear and Starling Basin brooks, support fish such as the longnose dace and the brook trout. Mountain goats are not indigenous to the area but can also be found here. They are descended from goats which were a gift from Canada to Custer State Park in 1924 but later escaped.
Mount Rushmore is largely composed of granite. The memorial is carved on the northwest margin of the Harney 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 Precambrian period about 1.6 billion years ago. Very coarse grained pegmatite is associated with the granite of Harney Peak. The light-colored streaks in the presidents' foreheads are due to these dikes.
Tourism is South Dakota's second-largest industry, and Mount Rushmore is its top tourist attraction. The memorial hosts nearly three million visitors a year. The site attracts many visitors over the week of the Sturgis Motorcycle Rally.
May 8 - August 13, 2011- 8:00 a.m. to 10:00 p.m., August 14 - September 30, 2011- 8:00 a.m. to 9:00 p.m., October 1, 2011 - May 7, 2012- 8:00 a.m. to 5:00 p.m.