# Relationship history for MSHA mine 4703663

Current hierarchy: **Mathy Construction Company → Milestone Materials Div/Mathy Construction Company → Plant 87**

- 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:** Mathy Construction Company → Plant 87; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Milestone Materials Div/Mathy Construction Company → Plant 87; 2012-07-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mathy Construction Company → Milestone Materials Div/Mathy Construction Company; 2012-07-24 to current/open; source msha-controller-operator-history