# Relationship history for MSHA mine 0504618

Current hierarchy: **Edward C  Levy Jr → Schmidt Aggregates → MENCENBERG 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:** Edward C  Levy Jr et al → MENCENBERG QUARRY; 1990-07-19 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Schmidt Aggregates → MENCENBERG QUARRY; 1998-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Edward C  Levy Jr et al → Schmidt Aggregates; 1998-06-01 to current/open; source msha-controller-operator-history