Methodology & source manifest
Everything on the Department of the Interior monitor derives from public records — the Interior FY2027 Budget in Brief (Appendix A, the A-18 reconciliation, and Appendix D receipts), the OMB Historical Tables, the USAspending API, and reachable DOI Agency Financial Reports / DOI OIG / GAO oversight documents. This page is the audit trail: method, sources, validation, and every flag.
Method
Net discretionary vs. the receipts frame
Interior is a net revenue generator: it collects more than $19.7B in FY2027 in energy and mineral leasing receipts — rents, bonuses, and royalties on Federal land and the Outer Continental Shelf, gathered through the Office of Natural Resources Revenue (ONRR) — which is more than its entire net-discretionary appropriation. Those receipts are revenue distributed to states, reclamation, and the Treasury; they are reported as their own frame and never netted into the discretionary headline. Folding them in would misstate what Congress actually appropriates. The headline is Net Discretionary — the appropriation after the published A-18 current-mandatory and offsetting-receipt adjustments — and the receipts sit beside it, not inside it.
Permanent / mandatory kept apart
Interior also carries permanent (mandatory) authority — the wildland-fire reserve, Indian and insular permanent payments, mineral-leasing payments to states, the excise-tax wildlife and sport-fish funds, and the NPS Capital Stewardship legislative proposal. This is a separate Net Permanent Authority frame, reported on its own and never inside the discretionary headline. Reading a permanent-authority swing as if it were an ordinary appropriation change is the cardinal error in the Interior budget — the same way the Wildfire Suppression Operations Reserve Fund cap-adjustment line is handled explicitly in the A-18 reconciliation rather than absorbed into the base.
Source documents & validation ledger
The history layer is shown in nominal dollars only — OMB Historical Table 5.2 publishes no constant-dollar basis, and no deflator is synthesized. It is agency-wide budget authority, which includes the one-time ARRA / IIJA / American Relief Act infrastructure surges; those are not conflated with the annual discretionary base. The energy/mineral receipts Interior collects and its permanent (mandatory) authority are kept strictly separate from the net-discretionary headline.