# Relationship history for MSHA mine 0900893

Current hierarchy: **Vulcan Materials Company → Florida Rock Industries Inc → Charlton Sand Mine**

- 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:** Florida Rock Industries Inc → Charlton Sand Mine; 1950-01-01 to 2007-11-15; source msha-controller-operator-history
- **controller_controls_mine:** Mc Govern Hal E → Charlton Sand Mine; 1950-01-01 to 1985-04-17; source msha-controller-operator-history
- **operator_operates_mine:** Davie Des Rocher Sand Company Inc → Charlton Sand Mine; 1978-03-09 to 1979-12-11; source msha-controller-operator-history
- **controller_controls_operator:** Mc Govern Hal E → Davie Des Rocher Sand Company Inc; 1978-03-09 to 1979-12-11; source msha-controller-operator-history
- **operator_operates_mine:** Florida Rock Industries Inc → Charlton Sand Mine; 1979-12-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Florida Rock Industries Inc → Florida Rock Industries Inc; 1979-12-12 to 2007-11-15; source msha-controller-operator-history
- **controller_controls_mine:** Vulcan Materials Company → Charlton Sand Mine; 2007-11-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Vulcan Materials Company → Florida Rock Industries Inc; 2007-11-16 to current/open; source msha-controller-operator-history