# Relationship history for MSHA mine 4001613

Current hierarchy: **Shipley Bradley → Shipley Coal Co → No 26 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:** Layne & Shipley Coal Co → No 26 Mine; 1974-01-01 to 1976-03-26; source msha-controller-operator-history
- **controller_controls_mine:** Layne & Shipley Coal Company → No 26 Mine; 1974-01-01 to 1976-03-26; source msha-controller-operator-history
- **controller_controls_operator:** Layne & Shipley Coal Company → Layne & Shipley Coal Co; 1974-01-01 to 1976-03-26; source msha-controller-operator-history
- **operator_operates_mine:** Shipley Coal Co → No 26 Mine; 1976-03-27 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Shipley Bradley → No 26 Mine; 1976-03-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Shipley Bradley → Shipley Coal Co; 1976-03-27 to current/open; source msha-controller-operator-history