Natural Resources and Environment covers the federal agencies that manage public lands, regulate environmental quality, and run conservation programs — about $69 billion in FY2024. Major recipients include the EPA (Clean Air and Water Act enforcement, Superfund cleanups, pesticide regulation), the Army Corps of Engineers civil works program (locks, dams, harbors, flood control), the US Forest Service (national forests + wildfire suppression), NOAA (National Weather Service, climate research, fisheries), and the National Park Service (63 National Parks + monuments).
Smaller but significant: the Bureau of Land Management (245M+ acres of public land), the US Fish & Wildlife Service (endangered species, hunting/fishing rules), USGS (earth-science research), and the Bureau of Reclamation (western water infrastructure). Conservation grants to states and tribal governments also flow through this function.