U.S. Department of the Interior
The Department of the Interior (DOI) manages public lands and minerals, national parks, and wildlife refuges and upholds Federal trust responsibilities to Indian tribes and Native Alaskans. Additionally, Interior is responsible for endangered species conservation and other environmental conservation efforts.
Contact details
Main address
1849 C St., NW Washington, DC 20240
Use this address block when you need the main headquarters mailing address or the official contact page for U.S. Department of the Interior.
Largest component agencies in Interior
This table shows the biggest component agencies or major organizational units reported under U.S. Department of the Interior in the latest OPM workforce summary.
| Agency | Employees | Total salary expense | Average pay | Share of department |
|---|---|---|---|---|
| National Park Service | 17,980 | $1,521,485,580 | $84,621 | 28.2% |
| Bureau of Land Management | 9,853 | $864,876,634 | $87,778 | 15.5% |
| U.s. Fish and Wildlife Service | 8,724 | $864,225,612 | $99,063 | 13.7% |
| Geological Survey | 8,305 | $855,689,065 | $103,033 | 13.0% |
| Bureau of Reclamation | 5,771 | $604,004,402 | $104,662 | 9.1% |
| Indian Affairs | 3,859 | $349,760,465 | $90,635 | 6.1% |
| Bureau of Indian Education | 3,071 | $214,368,084 | $69,804 | 4.8% |
| Office of the Secretary of the Interior | 3,034 | $407,684,648 | $134,372 | 4.8% |
| Bureau of Safety and Environmental Enforcement | 876 | $116,125,188 | $132,563 | 1.4% |
| Bureau of Ocean Energy Management | 623 | $88,039,245 | $141,315 | 1.0% |
| Office of the Solicitor | 541 | $85,007,330 | $157,130 | 0.8% |
| "Office of Surface Mining, Reclamation and Enforcement" | 416 | $50,385,504 | $121,119 | 0.7% |
| Bureau of Trust Funds Administration | 404 | $43,444,140 | $107,535 | 0.6% |
| Office of the Inspector General | 295 | $45,130,280 | $152,984 | 0.5% |
Component agency counts use the latest OPM summary release for March 2025. A few very small units may be rounded or grouped in the source file.
Contact details and office links come from the USA.gov agency directory. Workforce counts and average pay come from the latest OPM FedScope Employment Summary Data (March 2025).