# Relationship history for MSHA mine 3603561

Current hierarchy: **Prushnok Coal Company Inc → P & N Coal Company Inc → McClure Strip**

- 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:** P & N Coal Company Inc → McClure Strip; 1950-01-01 to 1987-06-30; source msha-controller-operator-history
- **controller_controls_mine:** Ralph W  Neal → McClure Strip; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ralph W  Neal → P & N Coal Company Inc; 1950-01-01 to 1987-06-30; source msha-controller-operator-history
- **operator_operates_mine:** P & N Coal Company Inc → McClure Strip; 1987-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Prushnok Coal Company Inc → McClure Strip; 1987-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Prushnok Coal Company Inc → P & N Coal Company Inc; 1987-07-01 to current/open; source msha-controller-operator-history