# Relationship history for MSHA mine 3609235

Current hierarchy: **Harry J  Silvers → Harry Silvers Quarry → Harry Silvers Quarry**

- 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:** Chuck's Rocks → Harry Silvers Quarry; 2004-04-27 to 2008-01-21; source msha-controller-operator-history
- **controller_controls_mine:** Charles E  Johnson → Harry Silvers Quarry; 2004-04-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Charles E  Johnson → Chuck's Rocks; 2004-04-27 to 2008-01-21; source msha-controller-operator-history
- **operator_operates_mine:** Harry Silvers Quarry → Harry Silvers Quarry; 2008-01-22 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Harry J  Silvers → Harry Silvers Quarry; 2008-01-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Harry J  Silvers → Harry Silvers Quarry; 2008-01-22 to current/open; source msha-controller-operator-history