Department of the Interior — Public Lands, Natural Resources & Tribal Relations

The Department of the Interior is the federal government's land manager, natural resource steward, and primary trustee for American Indian and Alaska Native tribes — a combination of responsibilities that makes it simultaneously one of the most economically consequential and most politically contested agencies in Washington. Interior manages approximately 480 million surface acres of federal land (roughly 1 in 5 U.S. acres), 700 million acres of federal subsurface mineral rights, and the outer continental shelf's vast oil, gas, and renewable energy resources. It is also the federal government's primary partner to the 574 federally recognized tribal nations, discharging a trust responsibility rooted in treaty obligations that are among the oldest legal commitments the United States has made. Established in 1849, Interior's enabling authority derives from 43 U.S.C. § 1451 et seq.; it has approximately 70,000 employees and a budget of roughly $18 billion, though the economic value of what it manages — in energy royalties, water rights, and ecosystem services — is orders of magnitude larger.

Legal Authority

• 43 U.S.C. § 1451 et seq. — Department of the Interior Organic Act of 1849: establishes the Department of the Interior and the Secretary of the Interior; general authority for Interior's management of federal public lands and natural resources
• 16 U.S.C. § 1 et seq. — National Park Service Organic Act of 1916: establishes the National Park Service and mandates management of NPS units to conserve unimpaired natural and cultural resources for present and future generations
• 25 U.S.C. § 2 et seq. — Indian affairs statutes: vests authority in the Secretary of the Interior for management of Indian affairs, trust responsibility to tribal nations, and administration of Indian trust lands and funds
• 16 U.S.C. § 1531 et seq. — Endangered Species Act of 1973: authorizes the Fish and Wildlife Service (FWS) to list threatened and endangered species, designate critical habitat, and enforce take prohibitions; shared authority with NOAA (Commerce) for marine species
• 43 U.S.C. § 1331 et seq. — Outer Continental Shelf Lands Act: authorizes BOEM (Bureau of Ocean Energy Management) to lease the outer continental shelf for offshore oil, gas, and renewable energy development

Key Mechanics

Interior manages federal public lands through multiple overlapping bureaus: the Bureau of Land Management (BLM) manages 245 million acres of surface lands primarily in the West under a multiple-use mandate (grazing, mining, energy, recreation); the National Park Service manages 85 million acres in 430+ units under a conservation-first mandate; the Fish and Wildlife Service manages 150 million acres of wildlife refuges. Energy extraction from federal lands — onshore oil and gas leases (BLM), offshore leases (BOEM), and coal leases — generates royalties collected by the Office of Natural Resources Revenue (ONRR); federal royalties on oil and gas are shared with producing states, making Interior's leasing decisions directly affect state budgets.

Organization & Structure

Interior is organized around eight primary bureaus plus the U.S. Geological Survey and the Office of Natural Resources Revenue (ONRR). The Secretary exercises policy direction through Assistant Secretaries for Land and Minerals Management, Water and Science, Fish and Wildlife and Parks, and Indian Affairs. The Bureau of Indian Affairs and Bureau of Indian Education operate under the Assistant Secretary for Indian Affairs, a position that carries both regulatory and trust-fiduciary responsibilities unique in the federal government.

Key Functions & Authorities

Bureau of Land Management (BLM) — the BLM manages 245 million acres of federal surface land — the largest single land management portfolio in the federal government — concentrated overwhelmingly in the eleven western states plus Alaska. BLM land is managed under the Federal Land Policy and Management Act of 1976 (FLPMA, 43 U.S.C. § 1701) under a "multiple use, sustained yield" mandate: the same lands can be open to grazing, mining, oil and gas drilling, recreation, and conservation simultaneously. BLM also administers 700 million acres of subsurface federal mineral rights, including issuing oil and gas leases on federal land under the Mineral Leasing Act of 1920. The 2021 Biden "30×30" initiative set a goal of conserving 30% of U.S. lands and waters by 2030, substantially affecting BLM planning. The Trump administration's 2019 relocation of BLM headquarters from Washington to Grand Junction, Colorado — and subsequent re-relocation under Biden — disrupted agency leadership and highlighted the political stakes of where federal land managers are physically located relative to the lands and the political branches they serve.

National Park Service (NPS) — NPS manages 423 units of the National Park System encompassing approximately 85 million acres across all 50 states and territories, including 63 designated national parks, 88 national monuments, 87 national historic sites, and a variety of other unit designations (seashores, recreation areas, parkways, battlefields). The Organic Act of 1916 (16 U.S.C. § 1) establishes NPS's dual mandate: to conserve natural and cultural resources "unimpaired for the enjoyment of future generations" — a tension between preservation and access that shapes every NPS management decision. NPS units attract approximately 330 million visits per year; the agency has a multi-billion dollar deferred maintenance backlog (estimated $22+ billion) representing decades of under-investment relative to visitation growth.

U.S. Fish and Wildlife Service (FWS) — FWS administers the Endangered Species Act (ESA, 16 U.S.C. § 1531) jointly with NOAA (for marine species), manages 150 million acres of National Wildlife Refuges (the largest wildlife-specific land system in the world), and enforces the Migratory Bird Treaty Act and other wildlife protection statutes. ESA listing decisions — which species receive "threatened" or "endangered" status and what critical habitat is designated — are among the most economically and politically contentious regulatory decisions Interior makes, with implications for development, agriculture, water use, and energy extraction across millions of acres. Sage-grouse listing decisions have been particularly contested, affecting oil and gas development across the Intermountain West. FWS also administers federal duck stamps, regulates international wildlife trade under CITES, and oversees migratory waterfowl management.

Bureau of Indian Affairs (BIA) — the BIA is the federal government's primary point of contact with the 574 federally recognized tribes, discharging a trust responsibility that derives from treaties, statutes, and court decisions dating to the earliest years of the republic. BIA functions include: managing approximately 56 million acres of tribal trust lands (the BIA holds title as trustee; the tribe holds beneficial interest); providing direct services (law enforcement, social services, roads) to tribes that have not contracted these functions; processing fee-to-trust land acquisitions (the mechanism by which tribes add to their trust land base); and administering the tribal recognition process (through the Office of Federal Acknowledgment) for groups seeking formal government-to-government status. The Indian Self-Determination and Education Assistance Act of 1975 (ISDEAA, 25 U.S.C. § 5321) enables tribes to contract and compact with BIA and IHS to administer programs themselves — a fundamental shift from direct federal service delivery to tribal self-governance that most larger tribes have exercised.

Bureau of Ocean Energy Management (BOEM) and Bureau of Safety and Environmental Enforcement (BSEE) — the 2010 Deepwater Horizon disaster resulted in the breakup of the former Minerals Management Service (MMS) into two successor agencies: BOEM (leasing and environmental review for offshore energy development) and BSEE (safety and environmental enforcement during operations). BOEM manages the leasing of the outer continental shelf (OCS) — covering approximately 1.7 billion acres — for oil, gas, and, increasingly, offshore wind. The 2022 Inflation Reduction Act required BOEM to offer oil and gas lease sales as a condition for offshore wind lease sales, creating statutory linkage between fossil fuel and clean energy leasing. Offshore wind lease auctions have generated billions in federal revenue and represent the fastest-growing component of BOEM's portfolio.

Bureau of Reclamation — Reclamation manages 337 dams and 185 reservoirs across 17 western states, storing and delivering approximately 10 trillion gallons of water per year for agricultural, municipal, and industrial use — the foundational infrastructure of the modern American West. Reclamation's projects include Hoover Dam (Lake Mead), Glen Canyon Dam (Lake Powell), and Grand Coulee Dam. The Colorado River system — the water source for 40 million people in seven states and Mexico — is managed through a complex interstate compact (Colorado River Compact, 1922) and a series of supplemental agreements; severe Lake Mead and Lake Powell drawdowns in 2021-2023 forced emergency water use reductions under the Bureau's Drought Contingency Plan authority for the first time in history.

U.S. Geological Survey (USGS) — USGS is Interior's scientific arm, conducting research and providing data across earth sciences, natural hazards (earthquakes, volcanoes, landslides), water resources, and biological sciences. USGS operates the National Earthquake Hazards Reduction Program, the Volcano Hazards Program (monitoring Kilauea, Rainier, and other active systems), the National Streamflow Information Program (real-time river gauges), and the National Land Imaging Program (Landsat satellite data). USGS data is foundational for infrastructure siting, natural hazard response, and federal land management decisions.

How It Affects You

If you are a citizen or voter: One in five acres in the United States is federal land managed by Interior — if you hike, camp, hunt, fish, or recreate outdoors in the West, you are almost certainly using BLM or Forest Service land. National parks are Interior's most visible public face; 330 million visits annually make the NPS one of the most-used government services in the country. If you live in the West, Reclamation's water delivery infrastructure likely supplies your municipal water or the agriculture in your region.

If you are a business or regulated entity: Energy companies operating on federal land (oil, gas, coal, geothermal, wind, solar) must obtain leases, permits, and approvals from BLM, BOEM, or BSEE depending on onshore vs. offshore location. Livestock operators hold approximately 18,000 BLM grazing permits covering 155 million acres. ESA critical habitat designations can restrict land use across vast areas; any project requiring a federal permit must undergo ESA Section 7 consultation with FWS or NOAA. Tribal gaming, land acquisitions, and federal contract opportunities flow through BIA processes that can take years.

If you work at a federal agency: Interior coordinates extensively with the Forest Service (USDA) on adjacent land management; with EPA on NEPA review, water quality, and hazardous waste on federal lands; with the Army Corps of Engineers on Section 404 wetlands permits that often overlap BLM and tribal lands; with FERC on hydropower licensing; and with DOE on energy development on federal land. The Indian trust responsibility creates legally unique obligations that affect how Interior must coordinate with tribes as sovereign governments rather than simply regulated parties.

If you are a journalist, researcher, or policy analyst: BLM publishes land use plans and leasing records on its eplanning portal; BOEM posts all offshore lease sale documents and bid results publicly. USGS's National Water Information System (waterdata.usgs.gov) provides real-time and historical streamflow data. The ONRR's Natural Resources Revenue Data portal (revenuedata.doi.gov) tracks all royalties, rents, and bonuses from federal energy production — a key source for natural resource revenue journalism. FWS's ESA database tracks all listed species and designated critical habitat.

Recent Developments

• 2025 — The Trump administration issued executive orders accelerating energy leasing on federal lands and waters, directing BLM and BOEM to expand oil, gas, and coal lease offerings and to revoke Biden-era conservation designations; Bears Ears and Grand Staircase-Escalante monument boundary reductions were again proposed, triggering tribal and environmental litigation.
• 2024 — The Supreme Court's Loper Bright Enterprises v. Raimondo (2024) decision overruling Chevron deference has significant implications for Interior rulemaking under FLPMA, ESA, and offshore energy statutes, requiring courts to independently interpret statutory ambiguities that Interior had previously filled through deference-backed regulation.
• 2023 — Bureau of Reclamation reached a historic 7-state Colorado River agreement on emergency water cuts to stabilize Lake Mead, averting the first-ever Tier 3 shortage declaration; drought conditions continued to reshape water allocation priorities across the Colorado River basin.
• 2022 — The Inflation Reduction Act required mandatory oil and gas lease sales as a precondition for offshore wind leasing, altered royalty rates for federal energy production, and provided $4 billion for western drought relief through the BOR; BOEM accelerated offshore wind leasing with record-setting Atlantic lease auctions.
• 2021 — The Biden administration's "America the Beautiful" initiative set a 30×30 conservation goal, directed Interior to pause new oil and gas leasing pending review, and reversed the 2019 BLM relocation; a federal court later ruled the oil and gas leasing pause exceeded Interior's statutory authority.