# Relationship history for MSHA mine 3604771

Current hierarchy: **Dando Frederick P-Harry David & Thomas W Martin → Locust Coal Company → No 1 Slope**

- 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:** Pewor Coal Co → No 1 Slope; 1973-01-01 to 1977-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Pewor Walter → No 1 Slope; 1973-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Pewor Walter → Pewor Coal Co; 1973-01-01 to 1977-05-31; source msha-controller-operator-history
- **operator_operates_mine:** Locust Coal Company → No 1 Slope; 1977-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Dando Frederick P-Harry David & Thomas W Martin → No 1 Slope; 1977-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dando Frederick P-Harry David & Thomas W Martin → Locust Coal Company; 1977-06-01 to current/open; source msha-controller-operator-history