# Relationship history for MSHA mine 3608923

Current hierarchy: **Johnson Charles E → Charles Johnson Quarry → CHARLES JOHNSON QUARRY #2**

- 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

- **controller_controls_mine:** Johnson Charles E → CHARLES JOHNSON QUARRY #2; 1997-06-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Charles Johnson Quarry → CHARLES JOHNSON QUARRY #2; 2001-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Johnson Charles E → Charles Johnson Quarry; 2001-03-01 to current/open; source msha-controller-operator-history