# Relationship history for MSHA mine 0405981

Current hierarchy: **Vulcan Materials Company → Triangle Rock Products → TRP Amador 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:** Legacy Vulcan Corp (Form:Vulcan Materials Co) → TRP Amador Quarry; 1950-01-01 to 2007-11-15; source msha-controller-operator-history
- **controller_controls_mine:** Calmat Company → TRP Amador Quarry; 1987-11-09 to 1999-01-05; source msha-controller-operator-history
- **controller_controls_mine:** Legacy Vulcan Corp (Form:Vulcan Materials Co) → TRP Amador Quarry; 1999-01-06 to 2007-11-15; source msha-controller-operator-history
- **controller_controls_mine:** Vulcan Materials Company → TRP Amador Quarry; 2007-11-16 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Vulcan Materials Company → TRP Amador Quarry; 2025-01-20 to 2025-07-31; source msha-controller-operator-history
- **controller_controls_operator:** Vulcan Materials Company → Vulcan Materials Company; 2025-01-20 to 2025-07-31; source msha-controller-operator-history
- **controller_controls_operator:** Legacy Vulcan Corp (Form:Vulcan Materials Co) → Vulcan Materials Company; 2025-01-20 to 2007-11-15; source msha-controller-operator-history
- **operator_operates_mine:** Triangle Rock Products → TRP Amador Quarry; 2025-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Vulcan Materials Company → Triangle Rock Products; 2025-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Legacy Vulcan Corp (Form:Vulcan Materials Co) → Triangle Rock Products; 2025-08-01 to 2007-11-15; source msha-controller-operator-history
- **controller_controls_operator:** Calmat Company → Triangle Rock Products; 2025-08-01 to 1999-01-05; source msha-controller-operator-history