# Relationship history for MSHA mine 0500138

Current hierarchy: **Edward C  Levy Jr → Schmidt Aggregates → Menzer 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:** Schmidt-Tiago Construction Company → Menzer Quarry; 1950-01-01 to 1980-07-18; source msha-controller-operator-history
- **controller_controls_mine:** Walter R  Schmidt → Menzer Quarry; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Walter R  Schmidt → Schmidt-Tiago Construction Company; 1950-01-01 to 1980-07-18; source msha-controller-operator-history
- **operator_operates_mine:** Schmidt-Tiago Construction Company → Menzer Quarry; 1980-07-19 to 1985-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Rogers Construction Inc → Menzer Quarry; 1980-07-19 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Rogers Construction Inc → Schmidt-Tiago Construction Company; 1980-07-19 to 1985-03-31; source msha-controller-operator-history
- **operator_operates_mine:** Cooley Gravel Company Of Colorado Springs Inc → Menzer Quarry; 1985-04-01 to 1988-07-18; source msha-controller-operator-history
- **controller_controls_mine:** J L Shiely  Company → Menzer Quarry; 1985-04-01 to 1988-07-18; source msha-controller-operator-history
- **controller_controls_operator:** J L Shiely  Company → Cooley Gravel Company Of Colorado Springs Inc; 1985-04-01 to 1988-07-18; source msha-controller-operator-history
- **operator_operates_mine:** Cooley Gravel Company Of Colorado Springs Inc → Menzer Quarry; 1988-07-19 to 1990-07-18; source msha-controller-operator-history
- **controller_controls_mine:** English China Clays PLC → Menzer Quarry; 1988-07-19 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** English China Clays PLC → Cooley Gravel Company Of Colorado Springs Inc; 1988-07-19 to 1990-07-18; source msha-controller-operator-history
- **operator_operates_mine:** Schmidt Aggregates → Menzer Quarry; 1990-07-19 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Edward C  Levy Jr et al → Menzer Quarry; 1990-07-19 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Edward C  Levy Jr et al → Schmidt Aggregates; 1990-07-19 to current/open; source msha-controller-operator-history