Supervises all operations and activities of the Department of the Interior and its constituent units, including the U.S. Fish and Wildlife Service, National Park Service, U.S. Geological Survey, Office of Surface Mining Reclamation and Enforcement, Bureau of Indian Affairs, Minerals Management Service, Bureau of Land Management, and Bureau of Reclamation; and, through the Office for Territorial and International Affairs, exercises departmental jurisdiction over U.S. dependencies. Supervised the U.S. Bureau of Mines and its predecessor, the Bureau of Mines, 1910-25 and 1934-96. Supervised the National Biological Service (NBS) and its predecessor, the National Biological Survey.