U.S. Department of the Interior

As part of its responsibilities, DOI oversees and fosters the use of more than 480 million acres of public lands, 700 million acres of subsurface minerals, and 1.7 billion acres of the outer continental shelf. Each year, Congress deliberates legislation that could affect DOI's management of this vast federal estate. As a result, understanding the roles and responsibilities of DOI's various components and offices is valuable when crafting legislation that affects the department's operations and ability to fulfill its mission. DOI primarily implements its responsibilities and mission through nine technical bureaus that make up more than 80% of the agency's workforce. These technical bureaus are the Bureau of Indian Affairs (BIA), Bureau of Land Management (BLM), Bureau of Ocean Energy Management (BOEM), Bureau of Reclamation (Reclamation), Bureau of Safety and Environmental Enforcement (BSEE), National Park Service (NPS), Office of Surface Mining Reclamation and Enforcement (OSMRE), U. S. Fish and Wildlife Service (FWS), and U. S. Geological Survey (USGS). Each of these bureaus has a unique mission and set of responsibilities, as well as a distinct organizational structure that serves to meet its functional duties. In addition to these technical bureaus, DOI has multiple departmental offices, which provide leadership, coordination, and services to DOI's various bureaus and programs. As of June 2018, DOI employed a staff of 69,563 nationwide across its bureaus and offices. However, total DOI employment figures fluctuate throughout the year, as some bureaus rely on seasonal and part-time staff, increasing staff totals during the summer months. The Office of Personnel Management (OPM) reports the average total DOI employment as 65,350 for the four reporting periods from September 2017 to June 2018. The largest bureau within DOI based on number of staff is NPS, which averaged close to 20,000 staff over the same time period-more than twice the size of the second-largest bureau, BLM. The smallest technical bureau by employment is OSMRE, which averaged just over 400 employees. Approximately 10% of all DOI staff are within the District of Columbia core-based statistical area (CBSA), which includes the District of Columbia and selected counties in Maryland, Virginia, and West Virginia.