# Relationship history for MSHA mine 1800271

Current hierarchy: **John R  Kortas → New Allegheny Inc → Harvey 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Grafton Coal Company → Harvey Mine; 1950-01-01 to 1979-06-12; source msha-controller-operator-history
- **controller_controls_mine:** Grafton Coal Company → Harvey Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Grafton Coal Company → Grafton Coal Company; 1950-01-01 to 1979-06-12; source msha-controller-operator-history
- **operator_operates_mine:** Oakland Coal Company → Harvey Mine; 1979-06-13 to 1983-05-11; source msha-controller-operator-history
- **controller_controls_mine:** PBS Coals Inc (Obsolete-see C15843) → Harvey Mine; 1979-06-13 to 1983-05-11; source msha-controller-operator-history
- **controller_controls_operator:** PBS Coals Inc (Obsolete-see C15843) → Oakland Coal Company; 1979-06-13 to 1983-05-11; source msha-controller-operator-history
- **operator_operates_mine:** Oakland Coal Company Inc → Harvey Mine; 1983-05-12 to 1985-10-17; source msha-controller-operator-history
- **controller_controls_mine:** NSM PLC → Harvey Mine; 1983-05-12 to 1985-10-17; source msha-controller-operator-history
- **controller_controls_operator:** NSM PLC → Oakland Coal Company Inc; 1983-05-12 to 1985-10-17; source msha-controller-operator-history
- **operator_operates_mine:** Allegheny Mining Corp → Harvey Mine; 1985-10-18 to 1990-07-25; source msha-controller-operator-history
- **controller_controls_mine:** FSS Coal Holding Inc → Harvey Mine; 1985-10-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** FSS Coal Holding Inc → Allegheny Mining Corp; 1985-10-18 to 1990-07-25; source msha-controller-operator-history
- **operator_operates_mine:** New Allegheny Inc → Harvey Mine; 1990-07-26 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** John R  Kortas → Harvey Mine; 1990-07-26 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John R  Kortas → New Allegheny Inc; 1990-07-26 to current/open; source msha-controller-operator-history