# Relationship history for MSHA mine 1515209

Current hierarchy: **Schweitzer Roy B → Trans-Oceanic Resources Inc → White Oak**

- 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:** Trans-Oceanic Resources Inc → White Oak; 1985-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Schweitzer Roy B → White Oak; 1985-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Schweitzer Roy B → Trans-Oceanic Resources Inc; 1985-05-01 to current/open; source msha-controller-operator-history