# Relationship history for MSHA mine 3001525

Current hierarchy: **Markcrow William E → Heathermoor Quarry Inc → Heathermoor Quarry Incorporated**

- 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:** Williams Brothers Slate Company → Heathermoor Quarry Incorporated; 1978-03-09 to 1983-09-29; source msha-controller-operator-history
- **controller_controls_mine:** Williams Fred C & Russell → Heathermoor Quarry Incorporated; 1978-03-09 to 1983-09-29; source msha-controller-operator-history
- **controller_controls_operator:** Williams Fred C & Russell → Williams Brothers Slate Company; 1978-03-09 to 1983-09-29; source msha-controller-operator-history
- **operator_operates_mine:** Heathermoor Quarry Inc → Heathermoor Quarry Incorporated; 1983-09-30 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Markcrow William E → Heathermoor Quarry Incorporated; 1983-09-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Markcrow William E → Heathermoor Quarry Inc; 1983-09-30 to current/open; source msha-controller-operator-history