# Relationship history for MSHA mine 1507729

Current hierarchy: **Mullins Elzy → Twin Ridge Coal Company → No 2-A 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Blue Ridge Coal Company → No 2-A Mine; 1974-01-01 to 1975-05-02; source msha-controller-operator-history
- **controller_controls_mine:** Cantrell Robert E → No 2-A Mine; 1974-01-01 to 1975-05-02; source msha-controller-operator-history
- **controller_controls_operator:** Cantrell Robert E → Blue Ridge Coal Company; 1974-01-01 to 1975-05-02; source msha-controller-operator-history
- **operator_operates_mine:** Twin Ridge Coal Company → No 2-A Mine; 1975-05-03 to 1976-03-15; source msha-controller-operator-history
- **controller_controls_mine:** Wellman Ermel-Bennett Et Al → No 2-A Mine; 1975-05-03 to 1976-03-15; source msha-controller-operator-history
- **controller_controls_operator:** Wellman Ermel-Bennett Et Al → Twin Ridge Coal Company; 1975-05-03 to 1976-03-15; source msha-controller-operator-history
- **operator_operates_mine:** Twin Ridge Coal Company → No 2-A Mine; 1976-03-16 to 1977-02-17; source msha-controller-operator-history
- **controller_controls_mine:** Hodge Harvey → No 2-A Mine; 1976-03-16 to 1977-02-17; source msha-controller-operator-history
- **controller_controls_operator:** Hodge Harvey → Twin Ridge Coal Company; 1976-03-16 to 1977-02-17; source msha-controller-operator-history
- **operator_operates_mine:** Twin Ridge Coal Company → No 2-A Mine; 1977-02-18 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Mullins Elzy → No 2-A Mine; 1977-02-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mullins Elzy → Twin Ridge Coal Company; 1977-02-18 to current/open; source msha-controller-operator-history