# Relationship history for MSHA mine 1500079

Current hierarchy: **Vulcan Materials Company → Vulcan Construction Materials, LLC → Fort Knox 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) → Fort Knox Quarry; 1950-01-01 to 2007-11-15; source msha-controller-operator-history
- **operator_operates_mine:** Cen-Ken Stone Company Inc → Fort Knox Quarry; 1950-01-01 to 1982-09-30; source msha-controller-operator-history
- **controller_controls_mine:** W J  Crowe → Fort Knox Quarry; 1950-01-01 to 1982-09-30; source msha-controller-operator-history
- **controller_controls_operator:** W J  Crowe → Cen-Ken Stone Company Inc; 1950-01-01 to 1982-09-30; source msha-controller-operator-history
- **operator_operates_mine:** Vulcan Constr. Materials, L.P. → Fort Knox Quarry; 1982-10-01 to 2001-11-30; source msha-controller-operator-history
- **controller_controls_operator:** Legacy Vulcan Corp (Form:Vulcan Materials Co) → Vulcan Constr. Materials, L.P.; 1982-10-01 to 2001-11-30; source msha-controller-operator-history
- **operator_operates_mine:** Vulcan Materials Company → Fort Knox Quarry; 2001-12-01 to 2003-02-10; source msha-controller-operator-history
- **controller_controls_operator:** Legacy Vulcan Corp (Form:Vulcan Materials Co) → Vulcan Materials Company; 2001-12-01 to 2003-02-10; source msha-controller-operator-history
- **operator_operates_mine:** Vulcan Construction Materials, LLC → Fort Knox Quarry; 2003-02-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Legacy Vulcan Corp (Form:Vulcan Materials Co) → Vulcan Construction Materials, LLC; 2003-02-11 to 2007-11-15; source msha-controller-operator-history
- **controller_controls_mine:** Vulcan Materials Company → Fort Knox Quarry; 2007-11-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Vulcan Materials Company → Vulcan Constr. Materials, L.P.; 2007-11-16 to 2001-11-30; source msha-controller-operator-history
- **controller_controls_operator:** Vulcan Materials Company → Vulcan Materials Company; 2007-11-16 to 2003-02-10; 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