# Relationship history for MSHA mine 3606211

Current hierarchy: **Heidelberg Materials AG → Essroc Cement → ESSROC CEMENT COPR.**

- 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:** Italcementi Spa → ESSROC CEMENT COPR.; 1950-01-01 to 2016-10-11; source msha-controller-operator-history
- **operator_operates_mine:** Mc Quiston Coal Company → ESSROC CEMENT COPR.; 1950-01-01 to 1995-08-13; source msha-controller-operator-history
- **controller_controls_mine:** Edwin M  Mc Quiston  et al → ESSROC CEMENT COPR.; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Edwin M  Mc Quiston  et al → Mc Quiston Coal Company; 1950-01-01 to 1995-08-13; source msha-controller-operator-history
- **operator_operates_mine:** Atlantic States Limestone Of Pa Inc → ESSROC CEMENT COPR.; 1995-08-14 to 1997-09-30; source msha-controller-operator-history
- **controller_controls_mine:** Bruntcliffe Aggregates PLC → ESSROC CEMENT COPR.; 1995-08-14 to 1997-09-30; source msha-controller-operator-history
- **controller_controls_operator:** Bruntcliffe Aggregates PLC → Atlantic States Limestone Of Pa Inc; 1995-08-14 to 1997-09-30; source msha-controller-operator-history
- **operator_operates_mine:** Atlantic States Limestone Of Pa Inc → ESSROC CEMENT COPR.; 1997-10-01 to 1999-03-23; source msha-controller-operator-history
- **controller_controls_mine:** Ennstone PLC → ESSROC CEMENT COPR.; 1997-10-01 to 1999-03-23; source msha-controller-operator-history
- **controller_controls_operator:** Ennstone PLC → Atlantic States Limestone Of Pa Inc; 1997-10-01 to 1999-03-23; source msha-controller-operator-history
- **operator_operates_mine:** Essroc Cement → ESSROC CEMENT COPR.; 1999-03-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Italcementi Spa → Essroc Cement; 1999-03-24 to 2016-10-11; source msha-controller-operator-history
- **controller_controls_mine:** Heidelberg Materials AG → ESSROC CEMENT COPR.; 2016-10-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Heidelberg Materials AG → Essroc Cement; 2016-10-12 to current/open; source msha-controller-operator-history