# Relationship history for MSHA mine 1512907

Current hierarchy: **Williamson Terry → T & R Coal Company → No 1 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:** Lobo Coal Inc → No 1 Mine; 1981-06-01 to 1981-09-09; source msha-controller-operator-history
- **controller_controls_mine:** Clevinger David-William Roscoe Et Al → No 1 Mine; 1981-06-01 to 1982-03-14; source msha-controller-operator-history
- **controller_controls_operator:** Clevinger David-William Roscoe Et Al → Lobo Coal Inc; 1981-06-01 to 1981-09-09; source msha-controller-operator-history
- **operator_operates_mine:** T & R Coal Company → No 1 Mine; 1981-09-10 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Williamson Terry → No 1 Mine; 1981-09-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Williamson Terry → T & R Coal Company; 1981-09-10 to current/open; source msha-controller-operator-history