The mission of the Yellowstone Research Library is to collect published and unpublished materials related to Yellowstone and to make these materials available to park staff, researchers, and the general public. The library collection encompasses over 20,000 books, periodicals, theses and dissertations, unpublished manuscripts, microforms of historical newspapers and scrapbooks, brochures, technical reports, and audio visual material. The Map Room collection includes a large number of published maps from 1865 to the present. In the Rare Book Room are the personal papers and books of notable figures from Yellowstone history, including Major Hiram Chittenden and several early superintendents. Donations from the Yellowstone Association, the Yellowstone Park Foundation, and private donors, as well funding provided by the National Park Service, have made possible an impressive, possibly unsurpassed, example of Yellowstone National Park resources.