# Relationship history for MSHA mine 2400781

Current hierarchy: **Dean  Studer → Midland O'Leary Inc → Billings 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:** Barry O'Leary Inc → Billings Pit; 1950-01-01 to 1987-07-05; source msha-controller-operator-history
- **controller_controls_mine:** O'Leary Agnes → Billings Pit; 1950-01-01 to 1987-07-05; source msha-controller-operator-history
- **controller_controls_operator:** O'Leary Agnes → Barry O'Leary Inc; 1950-01-01 to 1987-07-05; source msha-controller-operator-history
- **controller_controls_mine:** Dean  Studer → Billings Pit; 1987-07-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Midland O'Leary Inc → Billings Pit; 1987-07-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dean  Studer → Midland O'Leary Inc; 1987-07-06 to current/open; source msha-controller-operator-history