Call it a makeover of monumental proportions.
A crew began a project last week to wash the granite faces of Mount Rushmore to remove decades of dirt, grime and lichens that can damage the complexion of the four presidents.
The job could take five weeks.
Thorsten Mowes, a technician with the German company leading the project, started Thursday by spraying the left side of Thomas Jefferson's forehead with a stream of pressurized water.
It is the first time in Mount Rushmore's 65-year history that the famous South Dakota monument is getting such a cleaning.
The washings are compliments of a German manufacturer of cleaning machines that has donated 80 such projects around the world, said Frank Schad, spokesman for Alfred Karcher GmbH & Co.
"As a federal agency, we don't have a lot of money in our budget to be pressure-washing faces," said Judy Olson, Mount Rushmore's chief of interpretation. "When they said they would do it for free, that's when we started considering having this done."
Gutzon Borglum carved Mount Rushmore in blocks of granite that contained cracks. His maintenance plan called for filling them with white lead, linseed oil and granite dust. In 1991, the monument switched to a silicone sealant, and National Park Service workers dangle from harnesses each year to fill the cracks. But lichens still develop in crevices, producing an acid that can damage the faces.
Six Park Service rangers from Mount Rushmore and a volunteer from the nearby Crazy Horse Memorial are working with the company on the project.