The inventory of historic  properties should include all properties that are listed on or eligible for the  National Register of Historic Places to ensure that the military services  have visibility over all historical properties. In addition, a complete  inventory would ensure that the services are properly recording real  property transactions, ensure the accuracy of reporting on real property  required to be included in annual financial statements, and provide an  improved basis for long-term planning of facility maintenance and repair. At the same time, composite data on the costs of maintaining historic  structures is not readily available.
What GAO Found

Available information indicates that the Defense Department lacks an accurate inventory of historic properties. The inventory of historic military properties should include all properties that are listed on or eligible for the National Register of Historic Places. A complete inventory would ensure that the services are properly recording real property transactions, ensure the accuracy of reporting on real property required to be included in annual financial statements, and provide an improved basis for long-term planning for facility maintenance and repair. At the same time, composite data on the costs of maintaining historic structures are not readily available.