# Relationship history for MSHA mine 0400553

Current hierarchy: **Joseph  Baird → Lightweight Processing Company → Rocklite Pit & Mill**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Lightweight Processing Company → Rocklite Pit & Mill; 1950-01-01 to 1983-10-05; source msha-controller-operator-history
- **controller_controls_mine:** Vernon  Benfer → Rocklite Pit & Mill; 1950-01-01 to 1983-10-05; source msha-controller-operator-history
- **controller_controls_operator:** Vernon  Benfer → Lightweight Processing Company; 1950-01-01 to 1983-10-05; source msha-controller-operator-history
- **operator_operates_mine:** Lightweight Processing Company → Rocklite Pit & Mill; 1983-10-06 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Joseph  Baird → Rocklite Pit & Mill; 1983-10-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Joseph  Baird → Lightweight Processing Company; 1983-10-06 to current/open; source msha-controller-operator-history