Mount Rushmore (search) is getting a steam bath.

This month, America's four famous faces will be spotless, thanks to the hard work and daredevil maneuvers of rock-climbing crews from the national parks service and a private German company.

Karcher Corp., which is based in Stuttgart, donated workers and equipment to the United States to ensure the national monument stays intact. The monument in the Black Hills of South Dakota (search) presents the faces of past presidents George Washington, Thomas Jefferson, Theodore Roosevelt and Abraham Lincoln in stone.

“The main problem is the lichen. The plant has roots that drill themselves into the stone, even into granite,” said Thorsten Mowes, a project manager with Karcher.

Park rangers are spraying off lichen, which has been growing for years. If left on the monument, it causes the stone underneath to crumble. It is the first time in Mount Rushmore's 65-year history that it is getting such a cleaning.

“This is more than just a cleaning. This is a preservation stabilization activity. So we’re safeguarding this resource for our future generations,” said Duane Bubec, Mount Rushmore facilities manager.

Click in the box near the top of the story to watch a report by FOX News' Carol McKinley.