# Relationship history for MSHA mine 4100071

Current hierarchy: **Quikrete Holdings Inc. → Continental Cement Company, LLC → Midlothian Quarry and 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:** TXI (A/K/A Texas Industries Inc) → Midlothian Quarry and Plant; 1950-01-01 to 2005-03-14; source msha-controller-operator-history
- **controller_controls_mine:** Texas Industries Inc → Midlothian Quarry and Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Texas Industries Inc → TXI (A/K/A Texas Industries Inc); 1950-01-01 to 2005-03-14; source msha-controller-operator-history
- **controller_controls_mine:** Continental Cement Holding Company → Midlothian Quarry and Plant; 1996-06-21 to 2011-05-30; source msha-controller-operator-history
- **controller_controls_mine:** Texas Industries Inc → Midlothian Quarry and Plant; 2004-12-01 to 2014-07-01; source msha-controller-operator-history
- **operator_operates_mine:** Martin Marietta North Texas Cement, LLC → Midlothian Quarry and Plant; 2005-03-15 to 2026-03-04; source msha-controller-operator-history
- **controller_controls_operator:** Texas Industries Inc → Martin Marietta North Texas Cement, LLC; 2005-03-15 to 2014-07-01; source msha-controller-operator-history
- **controller_controls_mine:** Summit Materials LLC → Midlothian Quarry and Plant; 2011-05-31 to 2025-02-09; source msha-controller-operator-history
- **controller_controls_mine:** Martin Marietta Materials Inc → Midlothian Quarry and Plant; 2014-07-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta North Texas Cement, LLC; 2014-07-02 to 2026-03-04; source msha-controller-operator-history
- **controller_controls_mine:** Quikrete Holdings Inc. → Midlothian Quarry and Plant; 2025-02-10 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Continental Cement Company, LLC → Midlothian Quarry and Plant; 2026-03-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Summit Materials LLC → Continental Cement Company, LLC; 2026-03-05 to 2025-02-09; source msha-controller-operator-history
- **controller_controls_operator:** Continental Cement Holding Company → Continental Cement Company, LLC; 2026-03-05 to 2011-05-30; source msha-controller-operator-history
- **controller_controls_operator:** Quikrete Holdings Inc. → Continental Cement Company, LLC; 2026-03-05 to current/open; source msha-controller-operator-history