# Relationship history for MSHA mine 0102828

Current hierarchy: **Superfos America Inc → Couch Construction L P → PLANT 333**

- 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:** Superfos America Inc → PLANT 333; 1980-02-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Harper Henry J → PLANT 333; 1984-01-31 to 1997-02-23; source msha-controller-operator-history
- **operator_operates_mine:** Wiregrass Construction Company Inc → PLANT 333; 1989-10-01 to 1997-02-23; source msha-controller-operator-history
- **controller_controls_operator:** Harper Henry J → Wiregrass Construction Company Inc; 1989-10-01 to 1997-02-23; source msha-controller-operator-history
- **operator_operates_mine:** Couch Construction L P → PLANT 333; 1997-02-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Superfos America Inc → Couch Construction L P; 1997-02-24 to current/open; source msha-controller-operator-history