Presenting approximately 500 libraries and information sources through the National Natural Resources Library and Information System (NNRLIS), this directory identifies and locates the libraries within the jurisdiction of the Department of the Interior. The following departments are included: Office of the Secretary, Office of the Solicitor, Geological Survey, Bureau of Indian Affairs, Bureau of Land Management, Bureau of Mines, National Park Service, Heritage Conservation and Recreation Service, Bureau of Reclamation, and the Fish and Wildlife Service. The names and addresses of each library and information center are presented in summary form including the library telephone number(s), librarian, staff size, subject emphasis, collection size, special collections, services, and hours of operation. A geographical index, personnel index, and a subject index provide further information within the Department of Interior. Bureau of Indian Affairs schools and National Park Service sites are listed separately by state. (RTS)