# Relationship history for MSHA mine 1502976

Current hierarchy: **Coon Branch Coal Company Inc → Coon Branch Coal Company Inc → No 123 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:** E & M Coal Company → No 123 Mine; 1950-01-01 to 1971-12-01; source msha-controller-operator-history
- **controller_controls_mine:** E & M Coal Company → No 123 Mine; 1950-01-01 to 1971-12-01; source msha-controller-operator-history
- **controller_controls_operator:** E & M Coal Company → E & M Coal Company; 1950-01-01 to 1971-12-01; source msha-controller-operator-history
- **operator_operates_mine:** Salisbury Coal Company → No 123 Mine; 1971-12-02 to 1973-06-01; source msha-controller-operator-history
- **controller_controls_mine:** Salisbury Coal Company → No 123 Mine; 1971-12-02 to 1973-06-01; source msha-controller-operator-history
- **controller_controls_operator:** Salisbury Coal Company → Salisbury Coal Company; 1971-12-02 to 1973-06-01; source msha-controller-operator-history
- **operator_operates_mine:** Coon Branch Coal Company Inc → No 123 Mine; 1973-06-02 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Coon Branch Coal Company Inc → No 123 Mine; 1973-06-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Coon Branch Coal Company Inc → Coon Branch Coal Company Inc; 1973-06-02 to current/open; source msha-controller-operator-history