# Relationship history for MSHA mine 4606663

Current hierarchy: **Union Carbide Corp → Union Carbide Corp-Metals Division → Coalburg Mine No 1**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **controller_controls_mine:** Union Carbide Corp → Coalburg Mine No 1; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Union Carbide Corp-Metals Division → Coalburg Mine No 1; 1983-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Union Carbide Corp → Union Carbide Corp-Metals Division; 1983-06-01 to current/open; source msha-controller-operator-history