State lists of endangered, threatened, or rare species: An exploration of the literature

In 1990 we compiled an annotated bibliography of official state lists of endangered, threatened, and rare species. In gathering information for that bibliography, which appeared in Reference Services Review in Spring 1991, we found numerous unofficial sources of state lists, such as those developed by universities, institutes, and Natural Heritage Programs, which also provide valuable information on statuses of endangered, threatened, and rare species. A comprehensive search for unofficial lists results in this second bibliography.