# Relationship history for MSHA mine 0500412

Current hierarchy: **Pickens Operating Co & T Boone Pickens Jr → Mesa Operating Limited Partnership → Emperius**

- 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:** Minerals Engineering Company → Emperius; 1950-01-01 to 1986-04-03; source msha-controller-operator-history
- **controller_controls_mine:** Foust Tony → Emperius; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Foust Tony → Minerals Engineering Company; 1950-01-01 to 1986-04-03; source msha-controller-operator-history
- **controller_controls_mine:** Pioneer Corp → Emperius; 1980-02-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Pioneer Nuclear Inc → Emperius; 1986-04-04 to 1987-01-06; source msha-controller-operator-history
- **controller_controls_operator:** Pioneer Corp → Pioneer Nuclear Inc; 1986-04-04 to 1987-01-06; source msha-controller-operator-history
- **operator_operates_mine:** Mesa Operating Limited Partnership → Emperius; 1987-01-07 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Pickens Operating Co & T Boone Pickens Jr → Emperius; 1987-01-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Pickens Operating Co & T Boone Pickens Jr → Mesa Operating Limited Partnership; 1987-01-07 to current/open; source msha-controller-operator-history