# Relationship history for MSHA mine 2002787

Current hierarchy: **Acton Edward C & Michael E → Quality Aggregates → Pioneer Plant #1**

- 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

- **operator_operates_mine:** Quality Aggregates → Pioneer Plant #1; 1987-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Acton Edward C & Michael E → Pioneer Plant #1; 1987-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Acton Edward C & Michael E → Quality Aggregates; 1987-09-01 to current/open; source msha-controller-operator-history