# Relationship history for MSHA mine 0800884

Current hierarchy: **Vulcan Materials Company → Vulcan Construction Materials, LLC → POLK SAND PLANT**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Legacy Vulcan Corp (Form:Vulcan Materials Co) → POLK SAND PLANT; 1950-01-01 to 2007-11-15; source msha-controller-operator-history
- **controller_controls_mine:** Florida Rock Industries Inc → POLK SAND PLANT; 1950-01-01 to 2007-11-15; source msha-controller-operator-history
- **controller_controls_mine:** Moore Mc Cormack Resources Inc → POLK SAND PLANT; 1950-01-01 to 1988-09-05; source msha-controller-operator-history
- **operator_operates_mine:** Florida Mining & Materials Corp → POLK SAND PLANT; 1978-01-01 to 1988-09-05; source msha-controller-operator-history
- **controller_controls_operator:** Moore Mc Cormack Resources Inc → Florida Mining & Materials Corp; 1978-01-01 to 1988-09-05; source msha-controller-operator-history
- **operator_operates_mine:** Florida Mining & Materials Corp → POLK SAND PLANT; 1988-09-06 to 1991-11-30; source msha-controller-operator-history
- **controller_controls_mine:** Southdown Inc → POLK SAND PLANT; 1988-09-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Southdown Inc → Florida Mining & Materials Corp; 1988-09-06 to 1991-11-30; source msha-controller-operator-history
- **controller_controls_mine:** Vulcan Materials Co & Grupo Ica → POLK SAND PLANT; 1990-10-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Vulcan Construction Materials, LP → POLK SAND PLANT; 1991-12-01 to 2001-09-30; source msha-controller-operator-history
- **controller_controls_operator:** Vulcan Materials Co & Grupo Ica → Vulcan Construction Materials, LP; 1991-12-01 to 2001-09-30; source msha-controller-operator-history
- **operator_operates_mine:** Vulcan Construction Materials, L.P. → POLK SAND PLANT; 2001-10-01 to 2007-11-15; source msha-controller-operator-history
- **controller_controls_operator:** Legacy Vulcan Corp (Form:Vulcan Materials Co) → Vulcan Construction Materials, L.P.; 2001-10-01 to 2007-11-15; source msha-controller-operator-history
- **controller_controls_mine:** Vulcan Materials Company → POLK SAND PLANT; 2007-11-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Vulcan Materials Company → Vulcan Construction Materials, L.P.; 2007-11-16 to 2007-11-15; source msha-controller-operator-history
- **operator_operates_mine:** Florida Rock Industries Inc → POLK SAND PLANT; 2007-11-16 to 2010-08-31; source msha-controller-operator-history
- **controller_controls_operator:** Vulcan Materials Company → Florida Rock Industries Inc; 2007-11-16 to 2010-08-31; source msha-controller-operator-history
- **controller_controls_operator:** Florida Rock Industries Inc → Florida Rock Industries Inc; 2007-11-16 to 2007-11-15; source msha-controller-operator-history
- **operator_operates_mine:** Vulcan Construction Materials, LLC → POLK SAND PLANT; 2010-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Vulcan Materials Company → Vulcan Construction Materials, LLC; 2010-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Legacy Vulcan Corp (Form:Vulcan Materials Co) → Vulcan Construction Materials, LLC; 2010-09-01 to 2007-11-15; source msha-controller-operator-history