# Relationship history for MSHA mine 0400196

Current hierarchy: **UNACEM Corp S A A → UNACEM North America → Tehachapi Cement, LLC.**

- 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:** Monolith Portland Cement Company → Tehachapi Cement, LLC.; 1950-01-01 to 1989-03-30; source msha-controller-operator-history
- **controller_controls_mine:** Monolith Portland Cement Company → Tehachapi Cement, LLC.; 1950-01-01 to 1989-03-30; source msha-controller-operator-history
- **controller_controls_operator:** Monolith Portland Cement Company → Monolith Portland Cement Company; 1950-01-01 to 1989-03-30; source msha-controller-operator-history
- **controller_controls_mine:** Cimenteries Cbr Cementbedrijven → Tehachapi Cement, LLC.; 1980-04-07 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Calaveras Cement Company → Tehachapi Cement, LLC.; 1989-03-31 to 1999-05-11; source msha-controller-operator-history
- **controller_controls_operator:** Cimenteries Cbr Cementbedrijven → Calaveras Cement Company; 1989-03-31 to 1999-05-11; source msha-controller-operator-history
- **controller_controls_mine:** Heidelberg Materials AG → Tehachapi Cement, LLC.; 1999-05-12 to 2021-09-30; source msha-controller-operator-history
- **operator_operates_mine:** Lehigh Southwest Cement → Tehachapi Cement, LLC.; 1999-05-12 to 2021-04-30; source msha-controller-operator-history
- **controller_controls_mine:** Heidelberg Materials AG → Tehachapi Cement, LLC.; 1999-05-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Heidelberg Materials AG → Lehigh Southwest Cement; 1999-05-12 to 2021-04-30; source msha-controller-operator-history
- **operator_operates_mine:** Lehigh Cement West LLC → Tehachapi Cement, LLC.; 2021-05-01 to 2022-12-26; source msha-controller-operator-history
- **controller_controls_operator:** Heidelberg Materials AG → Lehigh Cement West LLC; 2021-05-01 to 2021-09-30; source msha-controller-operator-history
- **controller_controls_mine:** Martin Marietta Materials Inc → Tehachapi Cement, LLC.; 2021-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Lehigh Cement West LLC; 2021-10-01 to 2022-12-26; source msha-controller-operator-history
- **operator_operates_mine:** UNACEM North America → Tehachapi Cement, LLC.; 2022-12-27 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Martin Marietta Materials Inc → Tehachapi Cement, LLC.; 2022-12-27 to 2023-10-31; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → UNACEM North America; 2022-12-27 to 2023-10-31; source msha-controller-operator-history
- **controller_controls_mine:** UNACEM Corp S A A → Tehachapi Cement, LLC.; 2023-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** UNACEM Corp S A A → UNACEM North America; 2023-11-01 to current/open; source msha-controller-operator-history