# Relationship history for MSHA mine 0404592

Current hierarchy: **Phelps Dodge Corp → Phelps Dodge Zeolites → Mud Hills Mine**

- 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:** Occidental Minerals Corp → Mud Hills Mine; 1950-01-01 to 1983-02-15; source msha-controller-operator-history
- **controller_controls_mine:** Occidental Petroleum Corp → Mud Hills Mine; 1950-01-01 to 1983-02-15; source msha-controller-operator-history
- **controller_controls_operator:** Occidental Petroleum Corp → Occidental Minerals Corp; 1950-01-01 to 1983-02-15; source msha-controller-operator-history
- **operator_operates_mine:** Phelps Dodge Zeolites → Mud Hills Mine; 1983-02-16 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Phelps Dodge Corp → Mud Hills Mine; 1983-02-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Phelps Dodge Corp → Phelps Dodge Zeolites; 1983-02-16 to current/open; source msha-controller-operator-history