# Relationship history for MSHA mine 3600216

Current hierarchy: **Heidelberg Materials AG → Essroc Cement Corporation → Nazareth Plant 2**

- 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:** Italcementi Spa → Nazareth Plant 2; 1950-01-01 to 2016-10-11; source msha-controller-operator-history
- **controller_controls_mine:** Penn-Dixie Industries Inc → Nazareth Plant 2; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Penn-Dixie Industries Inc → Nazareth Plant 2; 1978-03-09 to 1980-09-23; source msha-controller-operator-history
- **controller_controls_operator:** Penn-Dixie Industries Inc → Penn-Dixie Industries Inc; 1978-03-09 to 1980-09-23; source msha-controller-operator-history
- **operator_operates_mine:** Essroc Cement Corporation → Nazareth Plant 2; 1980-09-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Italcementi Spa → Essroc Cement Corporation; 1980-09-24 to 2016-10-11; source msha-controller-operator-history
- **controller_controls_mine:** Heidelberg Materials AG → Nazareth Plant 2; 2016-10-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Heidelberg Materials AG → Essroc Cement Corporation; 2016-10-12 to current/open; source msha-controller-operator-history