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 average per year, enough to support abundant animal and plant life. Trees and other plants help to control surface runoff. Dikes, seeps, and springs help to dam up water that is flowing downhill, providing watering spots for animals. In addition, stones like sandstone and limestone help to hold groundwater, creating aquifers. A study of the fire scars present in tree ring samples indicates that forest fires occur in the ponderosa forests surrounding Mount Rushmore around every 27 years. Large fires are not common. Most events have been ground fires that serve to clear forest debris. The area is a climax