# Relationship history for MSHA mine 3400026

Current hierarchy: **Eagle Materials Inc → Central Plains Cement Co. → Tulsa 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:** Martin Marietta Cement → Tulsa Plant; 1950-01-01 to 1983-05-17; source msha-controller-operator-history
- **controller_controls_mine:** Martin Marietta Materials Inc → Tulsa Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta Cement; 1950-01-01 to 1983-05-17; source msha-controller-operator-history
- **operator_operates_mine:** Blue Circle Inc → Tulsa Plant; 1983-05-18 to 2001-07-11; source msha-controller-operator-history
- **controller_controls_mine:** Blue Circle Industries Plc → Tulsa Plant; 1983-05-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Blue Circle Industries Plc → Blue Circle Inc; 1983-05-18 to 2001-07-11; source msha-controller-operator-history
- **operator_operates_mine:** LaFarge Building Materials Incorporated → Tulsa Plant; 2001-07-12 to 2008-04-18; source msha-controller-operator-history
- **controller_controls_mine:** Lafarge S A → Tulsa Plant; 2001-07-12 to 2015-07-09; source msha-controller-operator-history
- **controller_controls_operator:** Lafarge S A → LaFarge Building Materials Incorporated; 2001-07-12 to 2008-04-18; source msha-controller-operator-history
- **operator_operates_mine:** Lafarge North America → Tulsa Plant; 2008-04-19 to 2012-11-29; source msha-controller-operator-history
- **controller_controls_operator:** Lafarge S A → Lafarge North America; 2008-04-19 to 2012-11-29; source msha-controller-operator-history
- **operator_operates_mine:** Central Plains Cement Co. → Tulsa Plant; 2012-11-30 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Eagle Materials Inc → Tulsa Plant; 2012-11-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Eagle Materials Inc → Central Plains Cement Co.; 2012-11-30 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Holcim Ltd → Tulsa Plant; 2015-07-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Holcim Ltd → LaFarge Building Materials Incorporated; 2015-07-10 to 2008-04-18; source msha-controller-operator-history
- **controller_controls_operator:** Holcim Ltd → Lafarge North America; 2015-07-10 to 2012-11-29; source msha-controller-operator-history