# Relationship history for MSHA mine 1512961

Current hierarchy: **Williamson Terry → Rough Branch Mining Inc → No 1**

- 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:** Buck Coal Inc → No 1; 1981-06-01 to 1981-09-16; source msha-controller-operator-history
- **controller_controls_mine:** Ethyl Corp → No 1; 1981-06-01 to 1981-09-16; source msha-controller-operator-history
- **controller_controls_operator:** Ethyl Corp → Buck Coal Inc; 1981-06-01 to 1981-09-16; source msha-controller-operator-history
- **operator_operates_mine:** F Taylor Mining Corp → No 1; 1981-09-17 to 1987-01-25; source msha-controller-operator-history
- **controller_controls_mine:** Taylor Fields Et Al → No 1; 1981-09-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Taylor Fields Et Al → F Taylor Mining Corp; 1981-09-17 to 1987-01-25; source msha-controller-operator-history
- **controller_controls_mine:** Blackburn Bobby Jr → No 1; 1984-04-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Wilderness Coal Inc → No 1; 1987-01-26 to 1987-06-17; source msha-controller-operator-history
- **controller_controls_operator:** Blackburn Bobby Jr → Wilderness Coal Inc; 1987-01-26 to 1987-06-17; source msha-controller-operator-history
- **operator_operates_mine:** Rough Branch Mining Inc → No 1; 1987-06-18 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Williamson Terry → No 1; 1987-06-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Williamson Terry → Rough Branch Mining Inc; 1987-06-18 to current/open; source msha-controller-operator-history