# Relationship history for MSHA mine 3400888

Current hierarchy: **Custom Coal Company → Custom Coal Company → No 1 Strip**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Higgins Mining Company Inc → No 1 Strip; 1975-05-01 to 1976-05-12; source msha-controller-operator-history
- **controller_controls_mine:** Higgins Mining Company Inc → No 1 Strip; 1975-05-01 to 1976-05-12; source msha-controller-operator-history
- **controller_controls_operator:** Higgins Mining Company Inc → Higgins Mining Company Inc; 1975-05-01 to 1976-05-12; source msha-controller-operator-history
- **operator_operates_mine:** Custom Coal Company → No 1 Strip; 1976-05-13 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Custom Coal Company → No 1 Strip; 1976-05-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Custom Coal Company → Custom Coal Company; 1976-05-13 to current/open; source msha-controller-operator-history