# Relationship history for MSHA mine 3603461

Current hierarchy: **A Ross  Myers → Independance Construction Materials → MORGANTOWN PLANT**

- 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:** General Crushed Stone Company → MORGANTOWN PLANT; 1950-01-01 to 1985-06-13; source msha-controller-operator-history
- **controller_controls_mine:** Koppers Company Inc → MORGANTOWN PLANT; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Koppers Company Inc → General Crushed Stone Company; 1950-01-01 to 1985-06-13; source msha-controller-operator-history
- **operator_operates_mine:** Sheridan Corp → MORGANTOWN PLANT; 1985-06-14 to 1998-11-11; source msha-controller-operator-history
- **controller_controls_mine:** Roy J  McMindes → MORGANTOWN PLANT; 1985-06-14 to 1998-11-11; source msha-controller-operator-history
- **controller_controls_operator:** Roy J  McMindes → Sheridan Corp; 1985-06-14 to 1998-11-11; source msha-controller-operator-history
- **controller_controls_mine:** A Ross  Myers → MORGANTOWN PLANT; 1988-11-17 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Independance Construction Materials → MORGANTOWN PLANT; 1998-11-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** A Ross  Myers → Independance Construction Materials; 1998-11-12 to current/open; source msha-controller-operator-history