The Lincoln Memorial, one of Americas most significant monuments, contains over 8,000 pieces of cut limestone and marble. EYP was retained by the National Park Service to conduct a study of the memorial and make recommendations for its preservation. The project scope included a physical and statistical survey of every stone, recorded on forms that included a proportionately accurate sketch of each stone, which resulted in a database of existing conditions that will help to direct future maintenance and preservation efforts. From this information, recommendations were made as to where intervention is needed, where it may be needed, and what type of intervention is appropriate. The Jules Guerin murals, inside the monument, were analyzed to determine the cause and extent of their damage and to provide recommendations for their conservation. A lighting study was undertaken mitigate the insect damage to the memorial. Preservation work so far includes removing marble staining by providing permanent hookups for water washing to the main roof, installing metal drip edges at the column capital blocks, replacing the system of copper lightning rods and cables at the penthouse with a non-staining metal, and repairing and replacing all copper roof elements.