# Relationship history for MSHA mine 1516792

Current hierarchy: **Johnson Harvey L → Copperhead Mining Company → Darby No 1 Mine**

- 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:** Charles  Turner → Darby No 1 Mine; 1985-07-01 to 1993-04-04; source msha-controller-operator-history
- **operator_operates_mine:** Tom Coal Company Inc → Darby No 1 Mine; 1989-12-01 to 1992-01-06; source msha-controller-operator-history
- **controller_controls_operator:** Charles  Turner → Tom Coal Company Inc; 1989-12-01 to 1992-01-06; source msha-controller-operator-history
- **operator_operates_mine:** Allied Mining Corp → Darby No 1 Mine; 1992-01-07 to 1993-03-17; source msha-controller-operator-history
- **controller_controls_mine:** Smith Lane → Darby No 1 Mine; 1992-01-07 to 1993-03-17; source msha-controller-operator-history
- **controller_controls_operator:** Smith Lane → Allied Mining Corp; 1992-01-07 to 1993-03-17; source msha-controller-operator-history
- **operator_operates_mine:** Coal Chase Corp → Darby No 1 Mine; 1993-03-18 to 1994-02-15; source msha-controller-operator-history
- **controller_controls_mine:** Sturgill Jerry → Darby No 1 Mine; 1993-03-18 to 1994-02-15; source msha-controller-operator-history
- **controller_controls_operator:** Sturgill Jerry → Coal Chase Corp; 1993-03-18 to 1994-02-15; source msha-controller-operator-history
- **operator_operates_mine:** Black Thunder Ltd → Darby No 1 Mine; 1994-02-16 to 1995-08-09; source msha-controller-operator-history
- **controller_controls_mine:** Montgomery Guy → Darby No 1 Mine; 1994-02-16 to 1995-08-09; source msha-controller-operator-history
- **controller_controls_operator:** Montgomery Guy → Black Thunder Ltd; 1994-02-16 to 1995-08-09; source msha-controller-operator-history
- **controller_controls_mine:** Duffield William → Darby No 1 Mine; 1995-01-05 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Crystal Energy Inc → Darby No 1 Mine; 1995-08-10 to 1996-02-26; source msha-controller-operator-history
- **controller_controls_operator:** Duffield William → Crystal Energy Inc; 1995-08-10 to 1996-02-26; source msha-controller-operator-history
- **operator_operates_mine:** Appalachian Fuels Inc → Darby No 1 Mine; 1996-02-27 to 1997-10-22; source msha-controller-operator-history
- **controller_controls_mine:** Gregory Robb → Darby No 1 Mine; 1996-02-27 to 1997-10-22; source msha-controller-operator-history
- **controller_controls_operator:** Gregory Robb → Appalachian Fuels Inc; 1996-02-27 to 1997-10-22; source msha-controller-operator-history
- **operator_operates_mine:** Copperhead Mining Company → Darby No 1 Mine; 1997-10-23 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Johnson Harvey L → Darby No 1 Mine; 1997-10-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Johnson Harvey L → Copperhead Mining Company; 1997-10-23 to current/open; source msha-controller-operator-history