# Relationship history for MSHA mine 2800463

Current hierarchy: **Heidelberg Materials AG → Mays Landing Sand & Gravel Company → DORCHESTER 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

- **operator_operates_mine:** Mays Landing Sand & Gravel Company Inc → DORCHESTER PLANT; 1950-01-01 to 1990-04-17; source msha-controller-operator-history
- **controller_controls_mine:** Frank  Romano → DORCHESTER PLANT; 1950-01-01 to 1995-01-04; source msha-controller-operator-history
- **controller_controls_operator:** Frank  Romano → Mays Landing Sand & Gravel Company Inc; 1950-01-01 to 1990-04-17; source msha-controller-operator-history
- **operator_operates_mine:** Vineland Group Inc → DORCHESTER PLANT; 1990-04-18 to 2002-06-30; source msha-controller-operator-history
- **controller_controls_mine:** Scancem Ans → DORCHESTER PLANT; 1990-04-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Scancem Ans → Vineland Group Inc; 1990-04-18 to 2002-06-30; source msha-controller-operator-history
- **operator_operates_mine:** Mays Landing Sand & Gravel Company → DORCHESTER PLANT; 2002-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Heidelberg Materials AG → DORCHESTER PLANT; 2002-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Heidelberg Materials AG → Mays Landing Sand & Gravel Company; 2002-07-01 to current/open; source msha-controller-operator-history