# Relationship history for MSHA mine 3002574

Current hierarchy: **Pine Hill Concrete Mix Corp → Buffalo Perlite → Buffalo Perlite Plant**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Buffalo Perlite → Buffalo Perlite Plant; 1980-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Pine Hill Concrete Mix Corp → Buffalo Perlite Plant; 1980-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Pine Hill Concrete Mix Corp → Buffalo Perlite; 1980-12-01 to current/open; source msha-controller-operator-history