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Saving Mount Rushmore

Mount Rushmore in South Dakota is a monument to four United States Presidents. Four very large heads carved in stone rise above the rocky land below. The Presidents are George Washington, Thomas Jefferson, Abraham Lincoln, and Theodore Roosevelt. The heads are 60 feet tall. That's nearly as long as 100 unsharpened pencils laid end-to-end.

The heads on Mount Rushmore are carved out of granite (GRAN iht). Granite is a kind of rock. Rain and wind are slowly wearing away the granite. The granite has cracks that may get bigger because of the rain and wind.

Geologists Try to Help

Geologists (jee AHL uh jihsts) are trying to keep Mount Rushmore from cracking and breaking. Geologists are scientists who study the Earth's soil and rocks. The geologists put cable wires and sensors on the monument. The cables help hold the rock together. The sensors are small machines that record the rock's movement and temperature.

The sensors are in places that are in the most danger. They are on the side of George Washington's head, the top of Theodore Roosevelt's head, and on Abraham Lincoln's face. The sensors send information to computers that make graphs for the scientists to study.

Safe for Now

Mount Rushmore has many cracks, but it is not going to break up soon. In some places, the geologists fill the crack with a liquid. The liquid also helps keep the cracks from getting bigger. Most geologists agree that all mountains move, shift, crack, and wear away. So Mount Rushmore is acting just like a normal mountain. We just worry about it more!