# Relationship history for MSHA mine 1503087

Current hierarchy: **Bartley Arthur Doug → Bartco Mining Company Inc → No 2 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:** R & S Coal Company → No 2 Mine; 1950-01-01 to 1987-02-12; source msha-controller-operator-history
- **controller_controls_mine:** Owens Paul B → No 2 Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Owens Paul B → R & S Coal Company; 1950-01-01 to 1987-02-12; source msha-controller-operator-history
- **controller_controls_mine:** Bartley Arthur Doug → No 2 Mine; 1986-10-20 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Bartco Mining Company Inc → No 2 Mine; 1987-02-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bartley Arthur Doug → Bartco Mining Company Inc; 1987-02-13 to current/open; source msha-controller-operator-history