# Relationship history for MSHA mine 1516441

Current hierarchy: **Hatfield Gregory & Larry Grace → G L K Coal Company Inc → No 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:** Preece Processing Inc → No 1; 1988-08-01 to 1990-01-03; source msha-controller-operator-history
- **controller_controls_mine:** Preece Homer & George → No 1; 1988-08-01 to 1990-01-03; source msha-controller-operator-history
- **controller_controls_operator:** Preece Homer & George → Preece Processing Inc; 1988-08-01 to 1990-01-03; source msha-controller-operator-history
- **controller_controls_mine:** Canterbury Percy → No 1; 1988-08-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** P B & G Mining Inc → No 1; 1990-01-04 to 1990-07-01; source msha-controller-operator-history
- **controller_controls_operator:** Canterbury Percy → P B & G Mining Inc; 1990-01-04 to 1990-07-01; source msha-controller-operator-history
- **operator_operates_mine:** Santee Coal Company Inc → No 1; 1990-07-02 to 1992-08-09; source msha-controller-operator-history
- **controller_controls_mine:** Bobby L  Fields → No 1; 1990-07-02 to 1992-08-09; source msha-controller-operator-history
- **controller_controls_operator:** Bobby L  Fields → Santee Coal Company Inc; 1990-07-02 to 1992-08-09; source msha-controller-operator-history
- **operator_operates_mine:** G L K Coal Company Inc → No 1; 1992-08-10 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hatfield Gregory & Larry Grace → No 1; 1992-08-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hatfield Gregory & Larry Grace → G L K Coal Company Inc; 1992-08-10 to current/open; source msha-controller-operator-history