# Relationship history for MSHA mine 1000973

Current hierarchy: **Eucon Corporation → De Atley Company Inc → Headquarters Pit**

- 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:** Potlatch Corp → Headquarters Pit; 1950-01-01 to 1978-11-29; source msha-controller-operator-history
- **controller_controls_mine:** Potlatch Corp → Headquarters Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Potlatch Corp → Potlatch Corp; 1950-01-01 to 1978-11-29; source msha-controller-operator-history
- **controller_controls_mine:** Eucon Corporation → Headquarters Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** De Atley Company Inc → Headquarters Pit; 1978-11-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Eucon Corporation → De Atley Company Inc; 1978-11-30 to current/open; source msha-controller-operator-history