“Bite-Size Bits of Local, National, and Global History”
“Bite-Size Bits of Local, National, and Global History”
Near Keystone in Pennington County, South Dakota — The American Midwest (Upper Plains)

The Power to Carve a Mountain

The Power to Carve a Mountain Marker image. Click for full size.
By Barry Swackhamer, September 6, 2015
1. The Power to Carve a Mountain Marker
Captions: (bottom left) Interior view of the compressor house showing two of the original compressors.; (bottom center) Workman on the mountain operating valve on a compressor line.; (top right) View of the compressor house in the later years of the carving with the Sculptor's Studio in the background. The white tank on the left of the picture is the receiver tank for the compressed air that was piped up the mountains.
Inscription. Over 450,000 tons of rock were removed from Mount Rushmore to bring out the four presidential faces. Although about 90% of the rock was removed with dynamite, the remaining rock was removed by drilling with jackhammers and wedging the rock off the mountain. The final finishing work on the faces was completed using small jackhammers and facing bits. Air compressors located here at the base of the mountain provided the power to operate the jackhammers.
The Ingersoll-Rand Imperial Type 10 Air Compressor displayed here was the largest of three in operation in the compressor house which stood at this location during the carving work. For much of the life of the carving, Keystone Consolidated Mines provided the electrical power to operate these compressors.
An 1,800-foot, 3-inch pipeline followed the stairway up the mountain to carry air for the jackhammers from the compressor below. In cold weather, a liquid gas was injected in a fine mist into the pipeline beyond the compressors to prevent freezing. The pipeline was later enlarged and expanded to provide compressed air to more jackhammers.
In 1936, Julian Spotts, a National Park Service engineer, checked this system for leaks. He discovered the blacksmith had tapped into the line with a nozzle to blow compressed air on himself while he worked! Spotts provided a fan instead.
The Power to Carve a Mountain Marker image. Click for full size.
By Barry Swackhamer, September 6, 2015
2. The Power to Carve a Mountain Marker

Spotts also tried to discover the reason for a large power loss suffered at Rushmore every Monday morning. "Well, I found," said Spotts, "that just about every woman in Keystone washed clothes on Monday, and a lot of them had electric washing machines." Instead of trying to rearrange Keystone's laundry schedule, Spotts asked the Mount Rushmore Commission to buy a gasoline-powered auxiliary compressor. "And after that," according to Spotts, "we had no more power problems." These improvements increased the minimum number of jackhammers that could be operated from 16 to 22.
Black Hills Power and Light completed a power line to Rushmore in 1939. This provided all the electricity needed for the remaining two years of carving work. Today, this compressor and sections of pipe still in place on Mount Rushmore stand as testimony to the power it took to carve a mountain.
Erected by National Park Service, Mount Rushmore Memorial.
Location. 43° 52.73′ N, 103° 27.275′ W. Marker is near Keystone, South Dakota, in Pennington County. Marker can be reached from South Dakota Route 244. Click for map. Marker is at or near this postal address: 13000 South Dakota Highway 244, Keystone SD 57751, United States of America.
Other nearby markers. At least 8 other markers are within 2 miles of this marker, measured as the crow flies. (Mount Rushmore) Chronology (about 400 feet away, measured in a direct line); History of the United States of America (about 400 feet away); Theodore Roosevelt (about 500 feet away); George Washington (about 700 feet away); Abraham Lincoln (approx. 0.2 miles away); Rushmore Workers (approx. 0.2 miles away); The Pigtail Bridges (approx. 1.2 miles away); Gutzon Borglum (approx. 1.6 miles away). Click for a list of all markers in Keystone.
More about this marker. This marker is located below the Sculptor's Studio at Mount Rushmore National Memorial.
Categories. Landmarks
Credits. This page originally submitted on , by Barry Swackhamer of San Jose, California. This page has been viewed 177 times since then and 64 times this year. Photos:   1, 2. submitted on , by Barry Swackhamer of San Jose, California. This page was last revised on June 16, 2016.
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