# Relationship history for MSHA mine 1512230

Current hierarchy: **Utter Ron J & Biff → T N T Coal Company Inc → Mine No 2-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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Utter Ron J & Biff → Mine No 2-Surface; 1976-08-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** T & R Mining Company → Mine No 2-Surface; 1979-12-01 to 1980-05-20; source msha-controller-operator-history
- **controller_controls_mine:** Pack Richard → Mine No 2-Surface; 1979-12-01 to 1982-04-18; source msha-controller-operator-history
- **controller_controls_operator:** Pack Richard → T & R Mining Company; 1979-12-01 to 1980-05-20; source msha-controller-operator-history
- **operator_operates_mine:** T N T Coal Company Inc → Mine No 2-Surface; 1980-05-21 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Utter Ron J & Biff → T N T Coal Company Inc; 1980-05-21 to current/open; source msha-controller-operator-history