# Relationship history for MSHA mine 3604691

Current hierarchy: **Oberlechner Steve Jr & Sr → O Coal Company → O 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:** Hibbs & Myers Coal Co → O Strip; 1950-01-01 to 1974-05-21; source msha-controller-operator-history
- **controller_controls_mine:** Myers William H → O Strip; 1950-01-01 to 1974-05-21; source msha-controller-operator-history
- **controller_controls_operator:** Myers William H → Hibbs & Myers Coal Co; 1950-01-01 to 1974-05-21; source msha-controller-operator-history
- **operator_operates_mine:** O Coal Company → O Strip; 1974-05-22 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Oberlechner Steve Jr & Sr → O Strip; 1974-05-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Oberlechner Steve Jr & Sr → O Coal Company; 1974-05-22 to current/open; source msha-controller-operator-history