# Relationship history for MSHA mine 3002577

Current hierarchy: **Horsehead Industries Inc → Zca Mines Inc → PIERREPONT PROPERTY**

- 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:** Fluor Corp → PIERREPONT PROPERTY; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** St Joe Resources Company → PIERREPONT PROPERTY; 1981-06-01 to 1987-09-16; source msha-controller-operator-history
- **controller_controls_operator:** Fluor Corp → St Joe Resources Company; 1981-06-01 to 1987-09-16; source msha-controller-operator-history
- **operator_operates_mine:** Zca Mines Inc → PIERREPONT PROPERTY; 1987-09-17 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Horsehead Industries Inc → PIERREPONT PROPERTY; 1987-09-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Horsehead Industries Inc → Zca Mines Inc; 1987-09-17 to current/open; source msha-controller-operator-history