Mount Rushmore National Memorial, located in the Black Hills of South Dakota, is known worldwide for its massive sculpture of four of the United States’ most respected presidents.
The monument is spread over an area of 517-ha landscape covered by dense pine forest. Construction of the Mount Rushmore monument commenced on 4 October 1927 and completed in 1941. Each of the four faces of US presidents that appear on Mount Rushmore is 60 ft tall.
Workers used a process known as honeycombing to remove the layer of rock from the mountain to crave the sculpture. This process entailed drilling a series of shallow holes and then wedging off the rock between them. The monument is currently under the jurisdiction of the National Park Service and attracts more than three million visitors annually.
Every summer at sundown, visitors gather in the hills of South Dakota at Mount Rushmore and rise to sing the national anthem. Darkness falls on the great stone faces as the sun sets and then a flashlight illuminates the mountain; the monument devoted to the great American presidents stands illuminated in a glowing light.
The ceremony at Mount Rushmore combines drama and patriotism. Invited by the South Dakota state historian Doane Robinson, the sculptor Gutzon Borglum could imagine the amalgamation of drama and patriotism being carved out on the mountain. He thought that sculpting a rock formation would definitely attract tourists.
Borglum was one of the world’s only artists with large-scale stone carving experience. He accepted Robinson’s invitation and traveled to South Dakota to investigate the area. Borglum began sketching his ideas for the sculpture. He wanted to honor presidents who had played important roles in US history.
He chose four presidents of the USA. First one was George Washington for his skills as a leader in the American Revolutionary War (1775‐1783) and for his work as the nation’s first president. The second one was, Thomas Jefferson, for his contribution in the declaration of independence and helping double the size of the nation. The third one was, Abraham Lincoln, for preserving the union and ending slavery during the American Civil War (1861‐1865). The fourth one was, Theodore Roosevelt, for his leadership that led to the building of the Panama Canal.
1. Design of the Monument
After the site selection, Borglum started to prepare for the work. Carving a mountain was a monumental task and without a design plan, the work could not begin. He started the design work at his studio in San Antonio, Texas.
The first step was to study the faces of the presidents he planned to carve. Borglum inspected the paintings and photographs of the presidents, looked at their life masks, and read the descriptions of how the presidents looked. Soon he was ready to begin making a model. The completed plaster prototype of Mount Rushmore was five feet tall. Borglum had made the model to a 1:12 scale. One inch on the model was equal to one foot on the mountain.
2. Site Preparation
Making a model was only the beginning. Next, he had to prepare the site. The first challenge was transportation. Without good roads, Borglum could not get supplies or workers to the site easily. He asked South Dakota’s governor for help. In July 1927, the state sent engineers to build new roads.
The next challenge was making a path up the mountain. Engineers designed a staircase for the workers which had 760 steps and several ramps. To transport tools and supplies, engineers built a tramway. It used pulleys and metal cables to carry a large bucket up and down the mountain hill.
Workers set up a camp on top of the mountain that had a repair shop for tools, sheds to store supplies, and shelter for the workers.
In addition to that, there was a powder house that held dynamite and a small studio that housed models. The top of the mountain also had several large winches. They were used to raise and lower the workers along the face of the mountain.
3. Use of the Pointing Machine
The workers needed measurements before they could start carving. Borglum made a pointing machine for this job. He would select a specific point on the model and then give his workers the same point to drill on the mountain.
Borglum used two pointing machines. One was on the model and the other one was on the mountain. Each pointing machine had a flat disk with the degrees of a circle marked on it. A shaft stood in the center of the disk with a long beam attached to it. The beam could rotate around the disk, similar to a propeller.
A cable ran out from the disk and hung off the beam. It could be lined up with the disk’s degree markings, and it had its own markings for feet and inches. A plumb bob hung down from the steel cable, holding it tightly in place. This kept the measurements accurate.
Measurements were taken in two ways using the pointing machine. Firstly, the measurements were taken in degrees by felling a plumb bob from a central point on the Presidents’ forehead. Secondly, the measurements were taken in distance units by measuring how far a point was above the plumb bob by using the markings on the cable itself. Borglum had stretched himself in new ways to create a system for carving the mountain.
4. Use of Winches
Winches played an essential role in the construction of Mount Rushmore. A winch is a simple machine for lifting heavy objects. It is made of a large drum with a crank attached to it. One end of a cable is attached to the drum. The other end of the cable is attached to a heavy object.
As the winch’s crank is turned, the cable winds around the drum. This shortens the cable, lifting the object at the other end. The top of the Mount Rushmore had six large, hand-cranked winches. Winch operators raised and lowered the men who carved the mountain.
5. Carving of the Monument
Despite all his planning, Borglum faced many problems. Geologists had warned him about the granite rock of the mountain. Granite has many fissures and is likely to deteriorate with time. They also believed the granite had blocks of schist mineral in it. This soft mineral breaks easily and could not be carved.
The only way for Borglum to know the rock’s condition was to start carving it. He sent crews to the top of the mountain. They buckled themselves into chairs that looked like children’s swings. Heavy cables connected each chair to a winch at the top of the mountain. A winch operator then lowered the worker down the side of the mountain. The first job was for the powder men.
These workers set off the dynamite to clear away the surface stone. This would expose the granite that Borglum planned to carve. The powder men placed the dynamite in drilled holes in the rock. Winch operators would then pull them back up to safety before crews detonated the dynamite.
With the surface rock gone, Borglum saw white streaks running through the underlying stone. The streaks were of pegmatite. It was a coarse-grained granite and could be carved easily. Borglum was satisfied and the project moved forward.
5.1 Roughing of the Presidents Face
The first blasts formed the rough outline of George Washington’s head. The next step was to locate the centerline of Washington’s head on the mountain.
Borglum watched the moonlight for several days to determine the best spot. With the center settled, the preliminary shape of the face could be carved.
Borglum used the pointing machine on his model to give workers their directions. Borglum measured each feature on the model and gave the measurements to the men called pointers. They located the point on the mountain that matched the point on the model. Then they painted directions on the mountain for the powder men.
The powder men shaped the rock to the rough dimensions of the face. They used a jackhammer to drill holes in the mountain. Then they cut sticks of dynamite to particular lengths based on the pointer directions.
The skilled crews could blast away very specific amounts of stone. Twice a day, the powder men placed dynamite in the holes and detonated it. The monument began to take shape.
5.2 Work on the Detailing
With the blasting on George Washington’s head complete, the crews were ready to add details. Drillers began working from the top of the face. This way they always had a ledge to place a scaffold. The workers stood on the scaffold while drilling. The drillers removed the stone to 6 inches of the finished measurements.
Drillers made closely spaced holes in the granite. This weakened the rock and made it easy to be removed by hand. After this, the scaffold was removed. The next crew worked in wooden cages attached to the winches. They used bumpers on the surface of the face. These power tools vibrated against the stone gently. This removed the stone a fraction of an inch at a time.
As the carvers finished their work, Borglum planned a dedication. On July 4th, 1930, more than 2,500 visitors traveled to Mount Rushmore for the ceremony. A massive American flag covered president Washington’s face. At a signal from the ground, winch operators on the mountain rolled up the flag and revealed the finished stone portrait of President Washington.
5.3 Problems Encountered During the Carving of Monument
Borglum next turned his attention to the face of president Thomas Jefferson. In Borglum’s model, president Jefferson sat just right to president Washington. Starting in 1931, the crew followed the same steps they had used in carving the president Washington face. They began by blasting away the surface stone and then they roughed the hair, forehead, eyes, and nose.
Problems soon arose while carving the face of president Jefferson. The rock was not suitable to carve and, also, Borglum did not like how the two faces looked next to each other on the mountain. Regardless of the reason, all the work on president Jefferson face was blasted away.
The crew started all over. This time they placed president Jefferson just left to president Washington.
This was not the last design change made to Borglum’s model. As the powder men blasted surface rock away, more problems became evident. The areas where Borglum had planned to carve had fissures. He adjusted his model nine times.
Each time, he had to check that the rock was good to carve. He also had to make sure the placement of the faces was pleasing to look at.
5.4 Finishing the Carving of the Monument
Work on Mount Rushmore was stopped several times due to lack of funds. Cold winter weather also stalled the work. As more money came in and the weather warmed up, Borglum would rehire his crew and start the work again. Slowly, they made progress.
As blasting and carving continued, Borglum’s design began to emerge from the mountainside. By July 1939, all four faces of the president had been dedicated. Detail work was still needed to be done, but the monument was nearly finished.
The project received bad news in early 1941. On March 6th, Borglum died following complications from surgery. His son, Lincoln, took over the project until it was completed that October. It had taken 14 years, but Borglum’s mountain monument had finally become a reality.
6. Maintenance Work at the Mount Rushmore
The US national park service (NPS) is responsible for the maintenance work at the Mount Rushmore Monument. Every year, Mount Rushmore is exposed to wind, snow, rain, and heat. Over time, these elements can cause damage. Park rangers are especially worried about how the weather affects the stone. If water settles in cracks and freezes, it expands. This can widen cracks and weaken the rock.
In 1989, the NPS began to study the cracks. Rangers mapped their locations. To do this, they divided a map of the monument into blocks. They identified four blocks that needed special attention. These blocks had significant cracks. If the cracks in these blocks grew, they could shift other blocks in the mountain.
This would change how the monument looks. The NPS study helped scientists understand the mountain’s structure. Rangers also examined the original sealant in the monument’s 144 cracks. Borglum had used sealant made of linseed oil, white lead, and granite dust. Over time, it had dried out. It no longer protected the cracks from water. Rangers removed the old sealant and replaced it with silicon caulk. This modern sealant can withstand the elements better.
In 1998, the NPS began to use a new system to take care of the monument. It installed electronic motion sensors on the mountain. The system takes measurements four times a day. It is very sensitive and can register movements as small as 0.0001 inches. Park rangers regularly monitor the movements and the readings show that the carvings are stable and in no danger.
Doane Robinson, a great historian from South Dakota, proposed the idea of craving a sculpture at Mount Rushmore.
Gutzon Borglum was the designer of Mount Rushmore.
George Washington, Thomas Jefferson, Abraham Lincoln, and Theodore Roosevelt.
The monument is located in the black hills of South Dakota, USA.
The construction for craving the sculpture at Mount Rushmore started in 1927 and the work was completed in 1941.
Borglum created the Mount Rushmore Monument to celebrate the 150 years of the USA as a free country.
The four presidents were chosen because of their important roles in the US history.
George Washington for his skills as a leader in the American Revolutionary War and for his work as the nation's first president.
Thomas Jefferson for his contribution to the declaration of independence of USA.
Abraham Lincoln for preserving the union and ending slavery during the American civil war.
Theodore Roosevelt for his leadership that lead to the building of the Panama Canal.