# Relationship history for MSHA mine 1500087

Current hierarchy: **Vulcan Materials Company → Vulcan Construction Materials, LLC → Grand Rivers 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) → Grand Rivers Quarry; 1950-01-01 to 2007-11-15; source msha-controller-operator-history
- **operator_operates_mine:** Reed Crushed Stone Company Inc → Grand Rivers Quarry; 1950-01-01 to 1990-09-05; source msha-controller-operator-history
- **controller_controls_mine:** David W  Reed → Grand Rivers Quarry; 1950-01-01 to 1990-09-05; source msha-controller-operator-history
- **controller_controls_operator:** David W  Reed → Reed Crushed Stone Company Inc; 1950-01-01 to 1990-09-05; source msha-controller-operator-history
- **operator_operates_mine:** Vulcan Construction Materials, LLC → Grand Rivers Quarry; 1990-09-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Legacy Vulcan Corp (Form:Vulcan Materials Co) → Vulcan Construction Materials, LLC; 1990-09-06 to 2007-11-15; source msha-controller-operator-history
- **controller_controls_mine:** Vulcan Materials Company → Grand Rivers Quarry; 2007-11-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Vulcan Materials Company → Vulcan Construction Materials, LLC; 2007-11-16 to current/open; source msha-controller-operator-history