# Relationship history for MSHA mine 4606004

Current hierarchy: **Arthur Lloyd → E & M Mining Company Inc → Number 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

- **operator_operates_mine:** Black Pearl Mining Company → Number 1 Mine; 1979-05-01 to 1981-02-24; source msha-controller-operator-history
- **controller_controls_mine:** Mason Martin E → Number 1 Mine; 1979-05-01 to 1981-02-24; source msha-controller-operator-history
- **controller_controls_operator:** Mason Martin E → Black Pearl Mining Company; 1979-05-01 to 1981-02-24; source msha-controller-operator-history
- **operator_operates_mine:** E & M Mining Company Inc → Number 1 Mine; 1981-02-25 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Arthur Lloyd → Number 1 Mine; 1981-02-25 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Arthur Lloyd → E & M Mining Company Inc; 1981-02-25 to current/open; source msha-controller-operator-history