# Relationship history for MSHA mine 1517708

Current hierarchy: **Jackie  Hembree → Headache Coal Company Inc → No 7**

- 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:** David  Grubb → No 7; 1989-05-10 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Gray Dennis → No 7; 1992-01-22 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Headache Coal Company Inc → No 7; 1995-09-01 to 1996-07-28; source msha-controller-operator-history
- **controller_controls_operator:** Gray Dennis → Headache Coal Company Inc; 1995-09-01 to 1996-07-28; source msha-controller-operator-history
- **operator_operates_mine:** G & P Contractors Inc → No 7; 1996-07-29 to 1997-02-16; source msha-controller-operator-history
- **controller_controls_operator:** David  Grubb → G & P Contractors Inc; 1996-07-29 to 1997-02-16; source msha-controller-operator-history
- **operator_operates_mine:** Headache Coal Company Inc → No 7; 1997-02-17 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Jackie  Hembree → No 7; 1997-02-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Jackie  Hembree → Headache Coal Company Inc; 1997-02-17 to current/open; source msha-controller-operator-history