# Relationship history for MSHA mine 1202119

Current hierarchy: **CRH PLC → Mulzer Crushed Stone, Inc → Mount Vernon Pit**

- 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:** Bart  Mulzer et al → Mount Vernon Pit; 1950-01-01 to 2017-02-09; source msha-controller-operator-history
- **controller_controls_mine:** Harry  McDonald → Mount Vernon Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** McDonald Sand & Gravel → Mount Vernon Pit; 1991-10-01 to 2014-11-05; source msha-controller-operator-history
- **controller_controls_operator:** Harry  McDonald → McDonald Sand & Gravel; 1991-10-01 to 2014-11-05; source msha-controller-operator-history
- **operator_operates_mine:** Mulzer Crushed Stone, Inc → Mount Vernon Pit; 2014-11-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bart  Mulzer et al → Mulzer Crushed Stone, Inc; 2014-11-06 to 2017-02-09; source msha-controller-operator-history
- **controller_controls_mine:** CRH PLC → Mount Vernon Pit; 2017-02-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** CRH PLC → Mulzer Crushed Stone, Inc; 2017-02-10 to current/open; source msha-controller-operator-history