# Relationship history for MSHA mine 0800388

Current hierarchy: **Mosaic Company → Mosaic Phosphates Company → PIERCE**

- 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

- **operator_operates_mine:** Agrico Mining Company → PIERCE; 1978-03-09 to 1987-07-31; source msha-controller-operator-history
- **controller_controls_mine:** Williams Companies → PIERCE; 1978-03-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Williams Companies → Agrico Mining Company; 1978-03-09 to 1987-07-31; source msha-controller-operator-history
- **operator_operates_mine:** Agrico Chemical Company → PIERCE; 1987-08-01 to 1993-06-30; source msha-controller-operator-history
- **controller_controls_mine:** Phosphate Resource Partners Lp → PIERCE; 1987-08-01 to 1993-06-30; source msha-controller-operator-history
- **controller_controls_operator:** Phosphate Resource Partners Lp → Agrico Chemical Company; 1987-08-01 to 1993-06-30; source msha-controller-operator-history
- **operator_operates_mine:** Imc-Agrico → PIERCE; 1993-07-01 to 2004-10-22; source msha-controller-operator-history
- **controller_controls_mine:** Mosaic Company → PIERCE; 1993-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mosaic Company → Imc-Agrico; 1993-07-01 to 2004-10-22; source msha-controller-operator-history
- **operator_operates_mine:** Mosaic Phosphates Company → PIERCE; 2004-10-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mosaic Company → Mosaic Phosphates Company; 2004-10-23 to current/open; source msha-controller-operator-history