# Relationship history for MSHA mine 1200066

Current hierarchy: **Heidelberg Materials AG → Heidelberg Materials US Cement LLC → Speed Cement 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Louisville Cement Company → Speed Cement Plant; 1950-01-01 to 1986-08-28; source msha-controller-operator-history
- **controller_controls_mine:** Louisville Cement Company → Speed Cement Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Louisville Cement Company → Louisville Cement Company; 1950-01-01 to 1986-08-28; source msha-controller-operator-history
- **controller_controls_mine:** Italcementi Spa → Speed Cement Plant; 1950-01-01 to 2016-10-11; source msha-controller-operator-history
- **operator_operates_mine:** Essroc Cement Corp → Speed Cement Plant; 1986-08-29 to 2017-04-30; source msha-controller-operator-history
- **controller_controls_operator:** Italcementi Spa → Essroc Cement Corp; 1986-08-29 to 2016-10-11; source msha-controller-operator-history
- **controller_controls_mine:** Heidelberg Materials AG → Speed Cement Plant; 2000-07-21 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Heidelberg Materials AG → Speed Cement Plant; 2016-10-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Heidelberg Materials AG → Essroc Cement Corp; 2016-10-12 to 2017-04-30; source msha-controller-operator-history
- **operator_operates_mine:** Heidelberg Materials US Cement LLC → Speed Cement Plant; 2017-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Heidelberg Materials AG → Heidelberg Materials US Cement LLC; 2017-05-01 to current/open; source msha-controller-operator-history