# Relationship history for MSHA mine 1516575

Current hierarchy: **Johnson Kurt E → Koal Inc → 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Phillips Processing → No 1; 1989-03-01 to 1989-05-22; source msha-controller-operator-history
- **controller_controls_mine:** Phillips Clyde N → No 1; 1989-03-01 to 1989-05-22; source msha-controller-operator-history
- **controller_controls_operator:** Phillips Clyde N → Phillips Processing; 1989-03-01 to 1989-05-22; source msha-controller-operator-history
- **operator_operates_mine:** Koal Inc → No 1; 1989-05-23 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Johnson Kurt E → No 1; 1989-05-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Johnson Kurt E → Koal Inc; 1989-05-23 to current/open; source msha-controller-operator-history