# Relationship history for MSHA mine 4500647

Current hierarchy: **Mc Closkey Robert F & Robert Lightfoot → Bo-Mac Gravel Company → Bo-Mac Pit And 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Bo-Mac Gravel Company → Bo-Mac Pit And Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Mc Closkey Robert F & Robert Lightfoot → Bo-Mac Pit And Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mc Closkey Robert F & Robert Lightfoot → Bo-Mac Gravel Company; 1950-01-01 to current/open; source msha-controller-operator-history