# Relationship history for MSHA mine 0800076

Current hierarchy: **Tarmac Plc → Tarmac Florida Inc → Rockland Key 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

- **operator_operates_mine:** Charley Toppino & Sons Inc → Rockland Key Quarry; 1950-01-01 to 1984-07-31; source msha-controller-operator-history
- **controller_controls_mine:** Frank P  Toppino → Rockland Key Quarry; 1950-01-01 to 1984-07-31; source msha-controller-operator-history
- **controller_controls_operator:** Frank P  Toppino → Charley Toppino & Sons Inc; 1950-01-01 to 1984-07-31; source msha-controller-operator-history
- **controller_controls_mine:** Lone Star Industries Inc → Rockland Key Quarry; 1979-01-01 to 1984-12-27; source msha-controller-operator-history
- **operator_operates_mine:** Lone Star Florida Inc → Rockland Key Quarry; 1984-08-01 to 1984-12-27; source msha-controller-operator-history
- **controller_controls_operator:** Lone Star Industries Inc → Lone Star Florida Inc; 1984-08-01 to 1984-12-27; source msha-controller-operator-history
- **operator_operates_mine:** Tarmac Florida Inc → Rockland Key Quarry; 1984-12-28 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Tarmac Plc → Rockland Key Quarry; 1984-12-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Tarmac Plc → Tarmac Florida Inc; 1984-12-28 to current/open; source msha-controller-operator-history