# Relationship history for MSHA mine 4601805

Current hierarchy: **Usx Corp → United States Steel Mining Company Inc → No 36 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:** Carbon Fuel Company → No 36 Mine; 1950-01-01 to 1982-06-11; source msha-controller-operator-history
- **controller_controls_mine:** ITT Corporation → No 36 Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** ITT Corporation → Carbon Fuel Company; 1950-01-01 to 1982-06-11; source msha-controller-operator-history
- **controller_controls_mine:** Usx Corp → No 36 Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** United States Steel Mining Company Inc → No 36 Mine; 1982-06-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Usx Corp → United States Steel Mining Company Inc; 1982-06-12 to current/open; source msha-controller-operator-history