Mount Rushmore climbers to monitor and seal cracks annually. Due to budget constraints, the memorial is not regularly cleaned to remove lichens. However, on July 8, 2005, Alfred Kärcher GmbH, a German manufacturer of pressure washing and steam cleaning machines, conducted a free cleanup operation which lasted several weeks, using pressurized water at over . The flora and fauna of Mount Rushmore are similar to those of the rest of the Black Hills region of South Dakota. Birds including the turkey vulture, bald eagle, hawk, and meadowlark fly around Mount Rushmore, occasionally making nesting spots in the ledges of the mountain. Smaller
Mount Rushmore in popular culture years and thus be one of the longest-lasting human artifacts. Because of this enduring structure, it has appeared in some science fiction set in the distant future: In addition to in "Pilotwings 64", Mount Rushmore also appears: American composer Michael Daugherty's 2010 piece for chorus and orchestra, "Mount Rushmore," depicts each of the four presidents in separate movements. The piece sets texts by George Washington, William Billings, Thomas Jefferson, Maria Cosway, Theodore Roosevelt, and Abraham Lincoln. Alice Cooper references Mount Rushmore in his album DaDa on the song "I love America" with the words, "I love that mountain with those