# Relationship history for MSHA mine 4606113

Current hierarchy: **Peabody Holding Company Inc → Peabody Coal Company → Rock Quarry**

- 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

- **controller_controls_mine:** Armco Inc → Rock Quarry; 1950-01-01 to 1989-09-30; source msha-controller-operator-history
- **operator_operates_mine:** Armco Inc → Rock Quarry; 1980-02-01 to 1984-02-26; source msha-controller-operator-history
- **controller_controls_operator:** Armco Inc → Armco Inc; 1980-02-01 to 1984-02-26; source msha-controller-operator-history
- **operator_operates_mine:** Peabody Coal Company → Rock Quarry; 1984-02-27 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Peabody Holding Company Inc → Rock Quarry; 1984-02-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Peabody Holding Company Inc → Peabody Coal Company; 1984-02-27 to current/open; source msha-controller-operator-history