# Relationship history for MSHA mine 2002927

Current hierarchy: **CRH PLC → Michigan Paving and Materials Company → Stoneco Portable #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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** R Smith & Sons Trucking Inc → Stoneco Portable #1; 1994-05-01 to 2021-09-14; source msha-controller-operator-history
- **controller_controls_mine:** Roger A  Smith → Stoneco Portable #1; 1994-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Roger A  Smith → R Smith & Sons Trucking Inc; 1994-05-01 to 2021-09-14; source msha-controller-operator-history
- **controller_controls_mine:** CRH PLC → Stoneco Portable #1; 2005-08-19 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Michigan Paving and Materials Company → Stoneco Portable #1; 2021-09-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** CRH PLC → Michigan Paving and Materials Company; 2021-09-15 to current/open; source msha-controller-operator-history