Heritage Documentation Programs

Heritage Documentation Programs (HDP) is a division of the U.S. National Park Service (NPS). It administers three programs established to document historic places in the United States: Historic American Buildings Survey (HABS), Historic American Engineering Record (HAER), and Historic American Landscapes Survey (HALS). Its records include measured drawings, archival photographs, and written reports, all archived in the Library of Congress' Prints and Photographs Division. Provided by Wikipedia