# Relationship history for MSHA mine 2901147

Current hierarchy: **Mississippi Chemical Corp → Mississippi Potash Inc → Mississippi Potash 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** National Potash Company → Mississippi Potash Incorporated; 1950-01-01 to 1983-01-03; source msha-controller-operator-history
- **controller_controls_mine:** Freeport Minerals Company → Mississippi Potash Incorporated; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Freeport Minerals Company → National Potash Company; 1950-01-01 to 1983-01-03; source msha-controller-operator-history
- **controller_controls_mine:** Kerr-McGee Corp → Mississippi Potash Incorporated; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Mississippi Chemical Corp → Mississippi Potash Incorporated; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Kerr-Mc Gee Chemical Corp → Mississippi Potash Incorporated; 1983-01-04 to 1984-10-16; source msha-controller-operator-history
- **controller_controls_operator:** Kerr-McGee Corp → Kerr-Mc Gee Chemical Corp; 1983-01-04 to 1984-10-16; source msha-controller-operator-history
- **operator_operates_mine:** National Potash Company → Mississippi Potash Incorporated; 1984-10-17 to 1985-06-20; source msha-controller-operator-history
- **controller_controls_operator:** Freeport Minerals Company → National Potash Company; 1984-10-17 to 1985-06-20; source msha-controller-operator-history
- **operator_operates_mine:** Mississippi Potash Inc → Mississippi Potash Incorporated; 1985-06-21 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mississippi Chemical Corp → Mississippi Potash Inc; 1985-06-21 to current/open; source msha-controller-operator-history