# Relationship history for MSHA mine 3607463

Current hierarchy: **Heidelberg Materials AG → Essroc Cement Corp → Essroc Cement Corp - Bessemer PA**

- 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 Corp - Bessemer PA; 1950-01-01 to 2016-10-11; source msha-controller-operator-history
- **operator_operates_mine:** Sme Bessemer Cement Inc → Essroc Cement Corp - Bessemer PA; 1983-05-01 to 1988-08-28; source msha-controller-operator-history
- **controller_controls_mine:** Michael  Carlow  et al → Essroc Cement Corp - Bessemer PA; 1983-05-01 to 1988-08-28; source msha-controller-operator-history
- **controller_controls_operator:** Michael  Carlow  et al → Sme Bessemer Cement Inc; 1983-05-01 to 1988-08-28; source msha-controller-operator-history
- **controller_controls_mine:** Lawrence  Ousky → Essroc Cement Corp - Bessemer PA; 1988-07-15 to 1990-09-10; source msha-controller-operator-history
- **operator_operates_mine:** United States Cement Company → Essroc Cement Corp - Bessemer PA; 1988-08-29 to 1990-02-26; source msha-controller-operator-history
- **controller_controls_operator:** Lawrence  Ousky → United States Cement Company; 1988-08-29 to 1990-02-26; source msha-controller-operator-history
- **operator_operates_mine:** Essroc Cement Corp → Essroc Cement Corp - Bessemer PA; 1990-02-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Italcementi Spa → Essroc Cement Corp; 1990-02-27 to 2016-10-11; source msha-controller-operator-history
- **controller_controls_mine:** Heidelberg Materials AG → Essroc Cement Corp - Bessemer PA; 2016-10-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Heidelberg Materials AG → Essroc Cement Corp; 2016-10-12 to current/open; source msha-controller-operator-history