# Relationship history for MSHA mine 0502719

Current hierarchy: **Steele Don → Steele Construction → Maybell Pit**

- 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:** Union Carbide Corp → Maybell Pit; 1950-01-01 to 1979-08-27; source msha-controller-operator-history
- **controller_controls_mine:** Union Carbide Corp → Maybell Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Union Carbide Corp → Union Carbide Corp; 1950-01-01 to 1979-08-27; source msha-controller-operator-history
- **operator_operates_mine:** Steele Construction → Maybell Pit; 1979-08-28 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Steele Don → Maybell Pit; 1979-08-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Steele Don → Steele Construction; 1979-08-28 to current/open; source msha-controller-operator-history