Mt. Rushmore National Memorial, Black Hills - Sout Dakota

Mt. Rushmore National Memorial is a huge mountain statue of four US Presidents, located near Keystone, in the Black Hills of South Dakota. The Presidents depicted are: George Washington, Thomas Jefferson, Theodore "Teddy" Roosevelt, and Abraham Lincoln. These four Presidents were chosen to represent the founding, growth and preservation of the United States. The work was designed by the sculptor John Gutzon Borglum (March 25, 1871- March 6, 1941).

The Construction of Mt. Rushmore National Memorial: The monument was sculpted by Borglum and about 400 stone workers. Construction began on August 10, 1927 (President Coolidge attended the dedication that day). Funding was provided by private donations and the Federal Government.

The sculpting Mount Rushmore Monument was done by first blasting away tons of rock with dynamite. Workers then sat in hanging "swing seats," and used jackhammers, drills, hammers, and other tools to do the finishing work. Bad weather and a lack of funding slowed work; although it took 14 years to finish the project, work was done for only about 6 of those years.

After Borglum's death, soon before the sculpture was done, the completion of the giant sculpture was overseen by his son, Lincoln Borglum. The Mount Rushmore monument was completed in 1941 (after Borglum's death).

Geology of the Area: The rock of Mount Rushmore consists of outcroppings of fine-grained granite (a hard, light-colored, igneous rock - volcanic rock that has cooled) and some mica schist (a type of crystalline metamorphic rock). The light-colored granite of Mt. Rushmore contrasts with darker layers of mica schist. Mt. Rushmore is the northeastern edge of the Harney Peak Granite Batholith (a batholith is a huge body of igneous rock that solidified under the earth).