# Relationship history for MSHA mine 3600039

Current hierarchy: **CRH PLC → Pennsy Supply Inc → PRESCOTT 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

- **controller_controls_mine:** Barbara M  Mumma → PRESCOTT QUARRY; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Calcite Quarry Corp → PRESCOTT QUARRY; 1950-01-01 to 1981-10-15; source msha-controller-operator-history
- **controller_controls_mine:** Iu Industrials Inc → PRESCOTT QUARRY; 1950-01-01 to 1981-10-15; source msha-controller-operator-history
- **controller_controls_operator:** Iu Industrials Inc → Calcite Quarry Corp; 1950-01-01 to 1981-10-15; source msha-controller-operator-history
- **controller_controls_mine:** Rangaire Corp → PRESCOTT QUARRY; 1981-09-23 to 1989-08-19; source msha-controller-operator-history
- **operator_operates_mine:** Corson Lime Company → PRESCOTT QUARRY; 1981-10-16 to 1985-12-08; source msha-controller-operator-history
- **controller_controls_operator:** Rangaire Corp → Corson Lime Company; 1981-10-16 to 1985-12-08; source msha-controller-operator-history
- **operator_operates_mine:** Lebanon Rock Inc → PRESCOTT QUARRY; 1985-12-09 to 1993-07-20; source msha-controller-operator-history
- **controller_controls_operator:** Barbara M  Mumma → Lebanon Rock Inc; 1985-12-09 to 1993-07-20; source msha-controller-operator-history
- **operator_operates_mine:** Pennsy Supply Inc → PRESCOTT QUARRY; 1993-07-21 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** CRH PLC → PRESCOTT QUARRY; 1993-07-21 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** CRH PLC → Pennsy Supply Inc; 1993-07-21 to current/open; source msha-controller-operator-history