# Relationship history for MSHA mine 3503016

Current hierarchy: **Matchett Roy L → Western Roads Inc → Howard Creek 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:** Matchett Roy L → Howard Creek Quarry; 1980-02-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Western Roads Inc → Howard Creek Quarry; 1980-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Matchett Roy L → Western Roads Inc; 1980-05-01 to current/open; source msha-controller-operator-history