The Digital Archaeological Record (tDAR) is an international digital repository for the digital records of archaeological investigations. tDAR’s use, development, and maintenance are governed by Digital Antiquity, an organization dedicated to ensuring the long-term preservation of irreplaceable archaeological data and to broadening the access to these data. The tDAR includes the entire National Archaeological Database (NADB) Reports module. The NADB was created by the National Park Service to identify and catalog the significant number of reports generated by archeological investigations for public projects across the United States. This type of material — often described as "grey literature" — is critical to archaeology but is typically published in small numbers, limited in its distribution, and difficult to discover or locate. Over the initial phase of NADB's development, the database captured and cataloged over 350,000 citations for archaeological reports or related materials.