# Relationship history for MSHA mine 1508487

Current hierarchy: **Sexton Gomer → J B Coal Company → No 1 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:** Christie Coal Company → No 1 Mine; 1975-07-16 to 1976-02-13; source msha-controller-operator-history
- **controller_controls_mine:** Christie Coal Company → No 1 Mine; 1975-07-16 to 1976-02-13; source msha-controller-operator-history
- **controller_controls_operator:** Christie Coal Company → Christie Coal Company; 1975-07-16 to 1976-02-13; source msha-controller-operator-history
- **operator_operates_mine:** Pugh Brothers Coal Company → No 1 Mine; 1976-02-14 to 1976-08-09; source msha-controller-operator-history
- **controller_controls_mine:** Pugh Lewis & James → No 1 Mine; 1976-02-14 to 1976-08-09; source msha-controller-operator-history
- **controller_controls_operator:** Pugh Lewis & James → Pugh Brothers Coal Company; 1976-02-14 to 1976-08-09; source msha-controller-operator-history
- **operator_operates_mine:** J B Coal Company → No 1 Mine; 1976-08-10 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Sexton Gomer Et Al → No 1 Mine; 1976-08-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Sexton Gomer Et Al → J B Coal Company; 1976-08-10 to current/open; source msha-controller-operator-history