# Relationship history for MSHA mine 4405223

Current hierarchy: **Barton Delmar → Westwood Coal Company → No 3**

- 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

- **controller_controls_mine:** Blackwell Gentry Et Al → No 3; 1979-03-01 to 1979-10-01; source msha-controller-operator-history
- **operator_operates_mine:** A & O Mining Inc → No 3; 1979-07-01 to 1979-08-19; source msha-controller-operator-history
- **controller_controls_operator:** Blackwell Gentry Et Al → A & O Mining Inc; 1979-07-01 to 1979-08-19; source msha-controller-operator-history
- **operator_operates_mine:** Laurel Mountain Mining Company → No 3; 1979-08-20 to 1980-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Esseks Robert D → No 3; 1979-08-20 to 1980-03-31; source msha-controller-operator-history
- **controller_controls_operator:** Esseks Robert D → Laurel Mountain Mining Company; 1979-08-20 to 1980-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Blackwell Gentry Et Al → No 3; 1980-03-27 to 1984-11-06; source msha-controller-operator-history
- **operator_operates_mine:** A & O Corp Of Virginia → No 3; 1980-04-01 to 1981-09-01; source msha-controller-operator-history
- **controller_controls_operator:** Blackwell Gentry Et Al → A & O Corp Of Virginia; 1980-04-01 to 1981-09-01; source msha-controller-operator-history
- **operator_operates_mine:** Big Valley Mining Inc → No 3; 1981-09-02 to 1983-05-17; source msha-controller-operator-history
- **controller_controls_mine:** Boardwine Richard → No 3; 1981-09-02 to 1983-05-17; source msha-controller-operator-history
- **controller_controls_operator:** Boardwine Richard → Big Valley Mining Inc; 1981-09-02 to 1983-05-17; source msha-controller-operator-history
- **operator_operates_mine:** Westwood Coal Company → No 3; 1983-05-18 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Barton Delmar → No 3; 1983-05-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Barton Delmar → Westwood Coal Company; 1983-05-18 to current/open; source msha-controller-operator-history