# Relationship history for MSHA mine 1800566

Current hierarchy: **FSS Coal Holding Inc → Allegheny Mining Corp → Bloch 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

- **controller_controls_mine:** PBS Coals Inc (Obsolete-see C15843) → Bloch Mine; 1950-01-01 to 1983-05-11; source msha-controller-operator-history
- **operator_operates_mine:** Allegheny Mining Corp → Bloch Mine; 1975-04-01 to 1983-05-11; source msha-controller-operator-history
- **controller_controls_operator:** PBS Coals Inc (Obsolete-see C15843) → Allegheny Mining Corp; 1975-04-01 to 1983-05-11; source msha-controller-operator-history
- **operator_operates_mine:** Allegheny Mining Corp Inc → Bloch Mine; 1983-05-12 to 1985-10-17; source msha-controller-operator-history
- **controller_controls_mine:** NSM PLC → Bloch Mine; 1983-05-12 to 1985-10-17; source msha-controller-operator-history
- **controller_controls_operator:** NSM PLC → Allegheny Mining Corp Inc; 1983-05-12 to 1985-10-17; source msha-controller-operator-history
- **operator_operates_mine:** Allegheny Mining Corp → Bloch Mine; 1985-10-18 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** FSS Coal Holding Inc → Bloch 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 current/open; source msha-controller-operator-history