# Relationship history for MSHA mine 3608573

Current hierarchy: **CRH PLC → Pennsy Supply Inc. → Small Mountain Quarry Inc-Salem Sand**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Earl R  Slusser → Small Mountain Quarry Inc-Salem Sand; 1988-08-01 to 1999-07-14; source msha-controller-operator-history
- **controller_controls_mine:** CRH PLC → Small Mountain Quarry Inc-Salem Sand; 1993-07-21 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Small Mountain Quarry Inc → Small Mountain Quarry Inc-Salem Sand; 1996-07-01 to 1999-07-14; source msha-controller-operator-history
- **controller_controls_operator:** Earl R  Slusser → Small Mountain Quarry Inc; 1996-07-01 to 1999-07-14; source msha-controller-operator-history
- **operator_operates_mine:** Small Mountain Quarry Inc → Small Mountain Quarry Inc-Salem Sand; 1999-07-15 to 2003-02-25; source msha-controller-operator-history
- **controller_controls_mine:** CRH PLC → Small Mountain Quarry Inc-Salem Sand; 1999-07-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** CRH PLC → Small Mountain Quarry Inc; 1999-07-15 to 2003-02-25; source msha-controller-operator-history
- **operator_operates_mine:** Pennsy Supply Inc. → Small Mountain Quarry Inc-Salem Sand; 2003-02-26 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** CRH PLC → Pennsy Supply Inc.; 2003-02-26 to current/open; source msha-controller-operator-history