# Relationship history for MSHA mine 1517142

Current hierarchy: **Metcalf Brutus D → North Star Energy Inc → #1**

- 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:** M C Coal Company Inc → #1; 1991-10-01 to 1992-10-26; source msha-controller-operator-history
- **controller_controls_mine:** Helton Walter M → #1; 1991-10-01 to 1992-10-26; source msha-controller-operator-history
- **controller_controls_operator:** Helton Walter M → M C Coal Company Inc; 1991-10-01 to 1992-10-26; source msha-controller-operator-history
- **operator_operates_mine:** M C Coal Company Inc → #1; 1992-10-27 to 1993-06-27; source msha-controller-operator-history
- **controller_controls_mine:** Shackleford Crystal → #1; 1992-10-27 to 1993-06-27; source msha-controller-operator-history
- **controller_controls_operator:** Shackleford Crystal → M C Coal Company Inc; 1992-10-27 to 1993-06-27; source msha-controller-operator-history
- **operator_operates_mine:** North Star Energy Inc → #1; 1993-06-28 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Metcalf Brutus D → #1; 1993-06-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Metcalf Brutus D → North Star Energy Inc; 1993-06-28 to current/open; source msha-controller-operator-history