# Relationship history for MSHA mine 4403645

Current hierarchy: **Steffey Jack → Steffey Trucking 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:** Tim Coal Company → No 1 Strip; 1973-01-01 to 1976-02-17; source msha-controller-operator-history
- **controller_controls_mine:** Roberts Joe H → No 1 Strip; 1973-01-01 to 1976-03-22; source msha-controller-operator-history
- **controller_controls_operator:** Roberts Joe H → Tim Coal Company; 1973-01-01 to 1976-02-17; source msha-controller-operator-history
- **operator_operates_mine:** Steffey Trucking Company → No 1 Strip; 1976-02-18 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Steffey Jack → No 1 Strip; 1976-02-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Steffey Jack → Steffey Trucking Company; 1976-02-18 to current/open; source msha-controller-operator-history