# Relationship history for MSHA mine 1502500

Current hierarchy: **J Mark  Campbell → Clintwood Elkhorn Mining Company Inc → Clintwood Elkhorn #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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Kentland-Elkhorn Coal Corp → Clintwood Elkhorn #1; 1950-01-01 to 1995-08-28; source msha-controller-operator-history
- **controller_controls_mine:** Pittston Company → Clintwood Elkhorn #1; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Pittston Company → Kentland-Elkhorn Coal Corp; 1950-01-01 to 1995-08-28; source msha-controller-operator-history
- **controller_controls_mine:** TECO Energy Inc → Clintwood Elkhorn #1; 1988-04-26 to 2015-09-20; source msha-controller-operator-history
- **operator_operates_mine:** Blackwell Coal Inc → Clintwood Elkhorn #1; 1995-08-29 to 1997-06-05; source msha-controller-operator-history
- **controller_controls_mine:** Berwind Corporation → Clintwood Elkhorn #1; 1995-08-29 to 1997-06-05; source msha-controller-operator-history
- **controller_controls_operator:** Berwind Corporation → Blackwell Coal Inc; 1995-08-29 to 1997-06-05; source msha-controller-operator-history
- **operator_operates_mine:** Clintwood Elkhorn Mining Company Inc → Clintwood Elkhorn #1; 1997-06-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** TECO Energy Inc → Clintwood Elkhorn Mining Company Inc; 1997-06-06 to 2015-09-20; source msha-controller-operator-history
- **controller_controls_mine:** James H  Booth et al → Clintwood Elkhorn #1; 2015-09-21 to 2019-06-15; source msha-controller-operator-history
- **controller_controls_operator:** James H  Booth et al → Clintwood Elkhorn Mining Company Inc; 2015-09-21 to 2019-06-15; source msha-controller-operator-history
- **controller_controls_mine:** J Mark  Campbell → Clintwood Elkhorn #1; 2019-06-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** J Mark  Campbell → Clintwood Elkhorn Mining Company Inc; 2019-06-16 to current/open; source msha-controller-operator-history