Where our information comes from and how we evaluate it.
We distinguish between three tiers of sources. This matters because the type of source directly affects the confidence grade we assign to a facility claim. Not all evidence carries the same weight.
Direct evidence from official government channels. These carry the highest evidentiary weight.
Highest confidence weight
Professional analysis and reporting on primary materials. Valuable corroboration when multiple sources agree.
Medium confidence weight
Unverified accounts and anecdotal evidence. These are documented but always labeled Unverified.
Cannot confirm alone
These are the primary databases and portals we use to research underground facilities. All are freely accessible to the public.
Official federal FOIA portal. Submit requests, track status, and access released records.
Federal spending data including contracts, grants, and financial assistance awards.
System for Award Management. Federal procurement opportunities and contract data.
Declassified documents, historical records, and government archives.
Nonpartisan research reports on policy issues prepared for Congressional members.
Government Accountability Office. Audits, evaluations, and investigative reports.
FOIA returns can look intimidating, but once you understand the common markings and patterns, they're readable. Here's what to look for.
Black bars (█) indicate removed text. When agencies redact information, they're required to indicate which exemption applies. Look for:
Most agencies use a cover letter or "Vaughn index" to explain their redactions. Key indicators:
Government contracts reveal construction and service activities. Key fields to examine:
Defense and military budgets use specific terminology. Look for:
Photographs, satellite imagery, and web content require their own verification methods. Here's how we evaluate digital evidence.
Web content can disappear or change. We archive sources to preserve evidence:
All web sources cited on this site include archived copies.
For submitted materials, we document the chain of custody: