# Relationship history for MSHA mine 4105381

Current hierarchy: **Martin Marietta Materials Inc → Martin Marietta Materials Southwest, LLC → 51 Sand and Gravel**

- 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:** Texas Industries Inc → 51 Sand and Gravel; 2004-12-01 to 2014-07-01; source msha-controller-operator-history
- **controller_controls_mine:** Martin Marietta Materials Inc → 51 Sand and Gravel; 2007-11-26 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Martin Marietta Materials Inc → 51 Sand and Gravel; 2014-07-02 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** 37 Mining LLC → 51 Sand and Gravel; 2018-07-30 to 2020-08-30; source msha-controller-operator-history
- **controller_controls_mine:** 37 Building Products Ltd → 51 Sand and Gravel; 2018-07-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** 37 Building Products Ltd → 37 Mining LLC; 2018-07-30 to 2020-08-30; source msha-controller-operator-history
- **operator_operates_mine:** TXI Operations → 51 Sand and Gravel; 2020-08-31 to 2023-01-29; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → TXI Operations; 2020-08-31 to 2023-01-29; source msha-controller-operator-history
- **controller_controls_operator:** Texas Industries Inc → TXI Operations; 2020-08-31 to 2014-07-01; source msha-controller-operator-history
- **operator_operates_mine:** Martin Marietta Materials Southwest, LLC → 51 Sand and Gravel; 2023-01-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta Materials Southwest, LLC; 2023-01-30 to current/open; source msha-controller-operator-history