A Site's NREligibility reflects whether it qualifies for the National Register of Historic Places, which drives legal protection and compliance obligations. ELIGIBLE means the site meets the criteria and warrants protection. NOT_ELIGIBLE means it was evaluated and does not qualify. UNDETERMINED means an evaluation has been made but no firm conclusion was reached. NEEDS_DATA means there is not yet enough information — more survey or testing is required before eligibility can be assessed. This determination feeds directly into Section 106 compliance reporting.
Technical section
Data model, API, and internals — visible to developers.