# Relationship history for MSHA mine 4604469

Current hierarchy: **Ahern James → Black Diamond Construction Inc → Montcoal Surface**

- 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:** Eagle Coal & Dock Company Inc → Montcoal Surface; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Armco Inc → Montcoal Surface; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hanson PLC → Montcoal Surface; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Eagle Coal & Dock Company Inc → Montcoal Surface; 1974-12-16 to 1980-01-09; source msha-controller-operator-history
- **controller_controls_operator:** Eagle Coal & Dock Company Inc → Eagle Coal & Dock Company Inc; 1974-12-16 to 1980-01-09; source msha-controller-operator-history
- **operator_operates_mine:** Armco Inc → Montcoal Surface; 1980-01-10 to 1984-02-26; source msha-controller-operator-history
- **controller_controls_operator:** Armco Inc → Armco Inc; 1980-01-10 to 1984-02-26; source msha-controller-operator-history
- **operator_operates_mine:** Peabody Coal Company → Montcoal Surface; 1984-02-27 to 1992-03-05; source msha-controller-operator-history
- **controller_controls_operator:** Hanson PLC → Peabody Coal Company; 1984-02-27 to 1992-03-05; source msha-controller-operator-history
- **controller_controls_mine:** John K  Skidmore → Montcoal Surface; 1986-12-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Johnstown Coal Company → Montcoal Surface; 1992-03-06 to 1994-04-28; source msha-controller-operator-history
- **controller_controls_operator:** John K  Skidmore → Johnstown Coal Company; 1992-03-06 to 1994-04-28; source msha-controller-operator-history
- **operator_operates_mine:** Black Diamond Construction Inc → Montcoal Surface; 1994-04-29 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Ahern James → Montcoal Surface; 1994-04-29 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ahern James → Black Diamond Construction Inc; 1994-04-29 to current/open; source msha-controller-operator-history